MECHANICAL PROPERTIES OF BOLTS AND SCREWS

8/20/2019 MECHANICAL PROPERTIES OF BOLTS AND SCREWS

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COMMON STANDARDS

EN ISO 898-1(EXTRACT)

MECHANICAL PROPERTIES OF BOLTS AND SCREWS

The following prescriptions conform to the contents of ISO 898/1, and apply to bolts and screws:• With coarse pitch thread M3 to M30, and fine pitch

thread from M8x1 to M30x2.• With triangular ISO thread in accordance with

ISO 68-1.• With diameter/pitch combinations in accordance with

ISO 261 and ISO 262

• With thread tolerance in accordance with ISO 965-1and ISO 965-2.

• Made of carbon steel or alloy steel.

It does not specify requirements for such properties as:Ability to withstand temperature above +300°C, or below–50°C.

1) Boron content can reach 0.005% provided thatnon-effective boron is controlled by addition of titanium and/or aluminium.

2) In case of plain carbon boron steel with a carboncontent below 0.25% (ladle analysis), the minimummanganese content shall be 0.6% for property class8.8 and 0.7% for property class 10.9.

3) For the materials of these property classes, it isintended that there should be a sufficienthardenability to ensure a structure consisting of approximately 90% martensite in the core of the threaded sections for the fasteners in the“as-hardened” condition before tempering.

4) This alloy steel shall contain at least one of thefollowing elements in the minimum quantity given:chromium 0.30%, nickel 0.30%, molybdenum

0.20%, vanadium 0.10%. Where elements arespecified in combinations of two, three or four andhave alloy contents less than those given above, thelimit value to be applied for class determination is70% of the sum of the individual limit values shownabove for the two, three or four elements concerned.

5) A metallographically detectable white phosphorousenriched layer is not permitted for property class 12.9.

Carbon steel- 0.55 0.05 0.06 0.003 -

- 0.55 0.05 0.06 0.003 -

Carbon steels with additives

(e.g. B, Mn or Cr) quenched and tempered

0.15 2) 0.40 0.035 0.035 0.003 425

Carbon steels with additives

(e.g. B, Mn or Cr) quenched and tempered0.20 2) 0.55 0.035 0.035 0.003

425

Alloy steel quenched and tempered 4) 0.20 0.55 0.035 0.035 0.003

Alloy steel quenched and tempered 4) 0.28 0.50 0.035 0.035 0.003 380

STEELS AND CHEMICAL ANALYSIS

Propertyclass Material and treatment

Chemical composition(check analysis), %

Temperingtemperature

min. °C

C P S B 1)

min. max. max. max. max.

4.8

6.8

8.8

10.9 3)

12.9 3) 5)


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1) For structural bolting the limit is 12 mm.

2) Surface hardness shall not be more than 30 Vickerspoints above the measured core hardness on theproduct when readings of both surface and core are

carried out at HV 0.3. For property class 10.9 any

increase in hardness at the surface which indicatesthat the surface hardness exceeds 390 HV is notacceptable.

Property class

4.8 6.8 8.8 10.9 12.9

- - d ≤ 16mm d > 16mm - -1) 1)

420 600 800 830 1040 1220

130 190 250 255 320 385220 250 320 335 380 435

- - 2)

340 480 - - - -

- - 640 660 940 1100

310 440 580 600 830 970

- - See ISO 898/7

- - 12 12 9 8

- - 52 52 48 44

- - 1/2 H1 1/2 H1 2/3 H1 3/4 H1

- - 0.015 0.015 0.015 0.015

- - Reduction of hardness 20HV maximum

In accordance with ISO 6157-1 or ISO 6157-3 as appropriate

Mechanical properties

Thread Diameter

Minimum tensile strengthRm N/mm2

Vickers hardness HVF≥98N

Surface hardness HV 0.3Lower yield stressReL N/mm2

Stress at 0.2% non proportionalelongationRp0.2 N/mm2

Stress under proof load Sp

Breaking torque MBElongation after fracture,AReduction of area after fracture,Z

Minimum height of non-decarburizedthread zone,EMaximum depth of completedecarburization,GHardness after retempering

Surface integrity

min.

min.max.

max.

min.

min.N/mm2

N/m min.

% min.

% min.

mm.

MECHANICAL PROPERTIES


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COMMON STANDARDS

EN ISO 2702(EXTRACT)

HEAT-TREATED STEEL TAPPING SCREWS

MECHANICAL PROPERTIES AND PERFORMANCE

The primary objective of this International Standard is toensure that tapping screws will form mating threads inmaterials into which they are normally driven withoutdeforming their own thread and without breaking duringassembly or service.

MaterialsThe material used is casehardening quality steel.

Acceptance

For routine acceptance test, the drive test, torsional testand core hardness test may be used.

Drive testThe sample screws (coated or uncoated, as received)shall be driven into a test plate until a thread of fulldiameter is completely through the test plate.The test plate shall be made of low carbon steel with acarbon content not exceeding 0,23%. The hardness of the plate shall be 130 HV to 170 HV. The thickness of theplate shall conform to the values given in the followingtable.The test hole shall be drilled, or punched and redrilled,

or reamed to the hole diameter specified in table for thesize of screw being tested.

2 1.30 1.17 1.955 1.905

3 1.30 1.17 2.235 2.185

4 1.30 1.17 2.465 2.415

5 1.30 1.17 2.730 2.680

6 2.06 1.85 2.970 2.9207 2.06 1.85 3.290 3.240

8 2.06 1.85 3.480 3.430

10 3.23 3.10 4.065 4.015

12 3.23 3.10 4.785 4.735

14 5.05 4.67 5.525 5.475

16 5.05 4.67 6.935 6.885

STANDARD TEST PLATE THICKNESS AND HOLE DIAMETER FOR DRIVE TEST

DesignationPlate thickness Hole diameter

N°mm. mm.

max. min. max. min.

Nominal threaddiameter

ST 2.2

ST 2.6

ST 2.9

ST 3.3

ST 3.5ST 3.9

ST 4.2

ST 4.8

ST 5.5

ST 6.3

ST 8


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Torsional strength testThe shank of the sample screw (coated or uncoated, asreceived) shall be clamped in a mating, split, threadeddie or other device so that the clamped portion of thescrew is not damaged and at least two full threadsproject above the clamping device and at least two full-form threads exclusive of point are held within theclamping device.A threaded insert with a blind hole may be used in place

of the clamping device provided that the hole depthis such as to ensure that breakage will occur beyondthe point.By means of a suitable calibrated torque-measuringdevice, torque shall be applied to the screw until failureoccurs.The screw shall meet the minimum torsional strengthrequirements given in the following table.

In cases where screws are plated subsequent to delivery

to the purchaser (or where plating of screws is otherwiseunder the control of the purchaser), the producer is notresponsible for failure due to plating.In such cases, the bolt manufacturer can only be held

responsible if it is proved that the failure is not due to any

post-treatment.Screws from which the plating has been stripped off cannot be considered as samples.

Nominalthread

diameter

DesignationMinimum torsional

N°strength

Nm

ST 2.2

ST 2.6

ST 2.9

ST 3.3

ST 3.5

ST 3.9ST 4.2

ST 4.8

ST 5.5

ST 6.3

ST 8

2 0.45

3 0.90

4 1.50

5 2.0

6 2.7

7 3.48 4.4

10 6.3

12 10.0

14 13.6

16 30.5


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COMMON STANDARDS

UNI 6946(EXTRACT)

TAPPING SCREWS

APPROXIMATE HOLE SIZES

The hole sizes in the present standard have beendetermined experimentally; when using them in a serie

production it is recommended to verify previously therevalues by proper testing.

HOLE SIZES FOR SHEET METALS

- 0.40 - 1.60 - -

0.40 0.50 - 1.60 - -0.50 0.60 - 1.70 - 1.650.60 0.80 - 1.80 - 1.650.80 0.90 - 1.90 - 1.650.90 1.20 - 1.90 - 1.701.20 1.50 - 1.95 - 1.80

- 0.40 2.20 2.20 - -0.40 0.50 2.20 2.20 - -0.50 0.60 2.50 2.30 2.20 -0.60 0.80 2.50 2.40 2.20 2.200.80 0.90 2.50 2.40 2.20 2.200.90 1.20 - 2.45 2.20 2.201.20 1.50 - 2.55 - 2.30

1.50 1.90 - 2.60 - 2.301.90 2.70 - - - 2.40- 0.40 2.85 2.65 - -

0.40 0.50 2.85 2.65 - -0.50 0.60 2.85 2.70 2.85 -0.60 0.80 2.85 2.70 2.85 2.650.80 0.90 2.85 2.80 2.85 2.650.90 1.20 - 2.85 2.85 2.651.20 1.50 - 2.95 - 2.701.50 1.90 - 3.10 - 2.801.90 2.70 - 3.25 - 2.852.70 6.30 - - - 3.10

- 0.50 3.10 2.95 - -0.50 0.60 3.10 2.95 3.10 -

0.60 0.80 3.10 2.95 3.10 2.900.80 0.90 3.10 2.95 3.10 2.900.90 1.20 3.10 3.10 3.10 2.951.20 1.50 - 3.25 - 3.101.50 1.90 - 3.50 - 3.251.90 2.70 - 3.60 - 3.502.70 6.30 - - - 3.60

- 0.50 3.50 - - -0.50 0.60 3.50 3.20 3.50 -0.60 0.80 3.50 3.20 3.50 2.950.80 0.90 3.50 3.20 3.50 3.100.90 1.20 3.50 3.25 3.50 3.251.20 1.50 - 3.50 - 3.50

1.50 1.90 - 3.60 - 3.601.90 2.70 - 3.80 - 3.752.70 3.20 - 3.80 - 3.753.20 3.40 - 3.90 - 3.803.40 9.50 - - - 3.90

Nominalthread

diameter

DesignationN°

Metalthickness

over until to

Hole size* for sheet metals in :

Steel, stainless and brass Aluminium alloy

Punched Drilled or Punched Drilled orholes trimmed holes holes trimmed holes

ST 2.2 2

ST 2.9 4

ST 3.5 6

ST 3.9 7

ST 4.2 8

Dimensions in mm.


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2.00 3.00 2.00 5.00 2.00 5.002.65 5.00 2.55 6.50 2.40 6.503.25 6.50 3.25 6.50 3.10 6.50

3.65 6.50 3.45 6.50 3.25 6.503.85 6.50 3.80 8.00 3.70 8.004.50 6.50 4.50 8.00 4.40 8.005.10 7.00 5.10 9.50 4.90 9.506.00 8.00 6.00 9.50 5.60 9.50

Nominalthread

diameter

DesignationN°

Aluminium, magnesium,Phenolic materials

Cellulosic, acrylic

zinc, brass, bronze casting and styrenic materials

Hole Depth of Hole Depth of Hole Depth of

size blind hole min. size blind hole min. size blind hole min.

ST 2.2 2ST 2.9 4ST 3.5 6

ST 3.9 7ST 4.2 8ST 4.8 10ST 5.5 12ST 6.3 14

* Recommended tolerance: H12

- 0.50 4.00 - - -0.50 0.60 4.00 3.70 4.00 -0.60 0.80 4.00 3.70 4.00 -0.80 0.90 4.00 3.75 4.00 3.700.90 1.20 4.00 3.90 4.00 3.701.20 1.50 - 3.90 - 3.701.50 1.90 - 4.00 - 3.751.90 2.70 - 4.10 - 3.752.70 3.20 - 4.30 - 3.80

3.20 3.40 - 4.30 - 3.803.40 4.20 - 4.40 - 3.904.20 9.50 - - - 4.10

- 0.60 4.70 4.20 - -0.60 0.80 4.70 4.20 - -0.80 0.90 4.70 4.20 - -0.90 1.20 4.70 4.30 - 4.101.20 1.50 - 4.50 - 4.251.50 1.90 - 4.70 - 4.401.90 2.70 - 4.70 - 4.602.70 3.20 - 5.00 - 4.703.20 3.40 - 5.00 - 4.703.40 4.20 - 5.10 - 4.804.20 9.50 - - - 5.00

- 0.80 5.3 5.00 - -0.80 0.90 5.3 5.00 - -0.90 1.20 5.3 5.00 - -1.20 1.50 - 5.10 - 5.101.50 1.90 - 5.20 - 5.101.90 2.70 - 5.30 - 5.202.70 3.20 - 5.80 - 5.303.20 3.40 - 5.80 - 5.303.40 4.20 - 6.00 - 5.404.20 4.80 - 6.00 - 4.404.80 4.90 - 6.00 - 5.604.90 9.50 - - - 5.80

Nominalthread

diameter

DesignationN°

Metalthickness

over until to

Hole size* for sheet metals in :

Steel, stainless and brass Aluminium alloy


ST 4.8 10

ST 5.5 12

ST 6.3 14

UNI 6946(EXTRACT)

HOLE SIZES FOR:ALUMINIUM, MAGNESIUM, ZINC, BRASS, BRONZE CASTING AND PLASTIC MATERIALS Dimensions in mm.


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HOLE SIZES FOR SHEET METALS

0.38 2.18 2.18 - -0.46 2.18 2.18 - -0.61 2.49 2.26 2.18 -0.76 2.49 2.39 2.18 2.180.91 2.49 2.39 2.18 2.181.22 - 2.44 2.18 2.18

1.52 - 2.54 - 2.261.91 - 2.59 - 2.260.38 2.82 2.64 - -0.46 2.82 2.64 - -0.61 2.82 2.69 2.82 -0.76 2.82 2.69 2.82 2.640.91 2.82 2.79 2.82 2.641.22 - 2.82 2.82 2.641.52 - 2.95 - 2.691.91 - 3.30 - 2.790.46 3.05 2.95 - -0.61 3.05 2.95 3.05 -0.76 3.05 2.95 3.05 2.87

0.91 3.05 2.95 3.05 2.871.22 3.05 3.05 3.05 2.951.52 - 3.25 - 3.051.91 - 3.45 - 3.250.46 3.45 - - -0.61 3.45 3.18 3.45 -0.76 3.45 3.18 3.45 2.950.91 3.45 3.18 3.45 3.051.22 3.45 3.25 3.45 3.251.52 - 3.45 - 3.451.91 - 3.56 - 3.560.46 3.99 3.66 - -0.61 3.99 3.66 3.99 -0.76 3.99 3.66 3.99 -0.91 3.99 3.73 3.99 3.661.22 3.99 3.78 3.99 3.661.52 - 3.91 - 3.661.91 - 3.99 - 3.730.46 - - - -0.61 4.70 4.22 - -0.76 4.70 4.22 - -0.91 4.70 4.22 - -1.22 4.70 4.32 - 4.091.52 - 4.50 - 4.221.91 - 4.62 - 4.390.46 - 4.98 - -0.61 - 4.98 - -

0.76 5.31 4.98 - -0.91 5.31 4.98 - -1.22 5.31 5.21 - -1.52 - 5.79 - 5.051.91 - 5.89 - 5.11

Nominalthread

diameter

DesignationN°

Metalthickness

ST 2.9 4

ST 3.5 6

ST 3.9 7

ST 4.2 8

ST 4.8 10

ST 6.3 1/4

ST 5.5 12

Hole size for sheet metals in :

Steel, stainless monel and brass Aluminium alloy


ASME B 18.6.4(EXTRACT)

TYPE AB THREAD TAPPING SCREWS

APPROXIMATE HOLE SIZES

Dimensions in mm.


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COMMON STANDARDS

SteelCasehardening steels.

Torsional testWhen the screw is exclusively subjected to torsion, theminimum breaking torque of the following table shall bereached before rupture occurs for the considerednominal threaded diameter.

The screw (with or without coating) shall be clamped ina cut device, having a blind hole, so that the clampedpart will not be damaged. At least two full threads shallprotrude over the device and at least two full threads,excluding the end, shall be clamped.

Nominal threaddiameter

mm

Minimum breakingtorque

Nm

3 1.00

3.5 1.45

4 2.15

4.5 2.85

5 4.35

5.5 6.55

6 9.15

7 15.60

UNI 7323-12(EXTRACT)

TAPPING SCREWS WITH TWO PROFILE THREAD ANDDOUBLE START FOR PLASTIC MATERIALS:

MECHANICAL PROPERTIES AND PERFORMANCE


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COMMON STANDARDS


MECHANICAL AND PERFORMANCE REQUIREMENTSOF THREAD ROLLING SCREWS

SteelsCasehardening steels.

Torsional testThe sample screw shall be securely clamped by suitablemeans with at least two full threads projecting above theclamping device, and at least two full threads exclusive of point, held within the clamping device.By means of a suitably calibrated measuring device,torque shall be applied to the screw until failure of the

screw occurs. The torque required to cause failure shall beequal to or exceed the minimum breaking torquespecified in the table.

Ability to forming the mating threadThe screw shall, (without permanent deformation of itsown thread), form a mating thread in a test plate havinga hardness HV 140 – 180, thickness equal to the nominaldiameter, with a drive speed not over 30 rpm in a holewhose diameter is given in the following table.During this test the drive torque shall not exceed themaximum values given in the table.

EmbrittlementFor these screws there is a risk of failure due to hydrogenembrittlement, especially if they are electroplated.Therefore process investigation shall be conductedaccording to ISO 15330.

In the case of electroplating, hydrogen embrittlementrelief treatment in accordance with ISO 4042 shall beapplied.Non electrolytic applied coating are preferred.

Nominalthread

diameterd

Plate thickness

Hole diameterThickness mm.

mm. max. min.

Maximum Minimum Minimum tensile

drive torque breaking torque breaking load*

Nm Nm N

M2.5M3

M3.5

M4

M5

M6

M8

2.5 2.275 2.250 0.6 1.2 3 1503 2.775 2.750 1.1 2.1 4 680

3.5 3.180 3.150 1.7 3.4 6 300

4 3.680 3.650 2.5 4.9 8 170

5 4.530 4.500 5.0 10.0 13 200

6 5.430 5.400 8.5 17.0 18 700

8 7.336 7.300 21.0 42.0 34 000

* For information only.


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COMMON STANDARDS

UNI 8108(EXTRACT)

THREAD ROLLING SCREWSAPPROXIMATE HOLE SIZES

2.25 2.30 2.35 - - 2.20 2.25 2.302.70 2.75 2.80 - - 2.70 2.70 2.75

3.10 3.20 3.20 3.25 3.30 3.10 3.10 3.20 3.30 3.25

3.60 3.70 3.75 3.75 3.80 3.60 3.70 3.70 3.75

- 4.50 4.60 4.70 4.70 4.50 4.50 4.60 4.70

- 5.40 5.50 5.60 5.70 5.40 5.40 5.50 5.60

- 7.30 7.40 7.50 7.60 7.30 7.30 7.40 7.50

Threaddiameter

d

Materials

Steel, stainless steel and brass Aluminium and its alloysMetal thickness mm. Metal thickness mm.

Hole size Hole sizeH11 H11

from 0.5 from 2 from 3.5 from 6.8 from 9 from 0.5 from 2 from 3.5 from 6.8 from 9up to 2 up to 3.5 up to 6.8 up to 9 up to 13 up to 2 up to 3.5 up to 6.8 up to 9 up to 13

M2.5M3

M3.5

M4

M5

M6

M8

APPROXIMATE TRIMMEDOR DRILLED HOLE SIZES FOR SHEET METALS Dimensions in mm.


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COMMON STANDARDS

DIN 7513 DIN 7516(EXTRACT)

THREAD CUTTING SCREWS:MECHANICAL PROPERTIES AND PERFORMANCE

SteelsCasehardening screws.

Torsional testThe sample screw shall be securely clamped by suitablemeans with at least two full threads projecting above theclamping device, and at least two full threads exclusiveof point, held within the clamping device.By means of a suitably calibrated measuring device,torque shall be applied to the screw until failure of the

screw occurs. The torque required to cause failure shallbe equal to or exceed the minimum breaking torquespecified in the table.

Ability to forming the mating threadThe screw shall, without permanent deformation of itsown thread, form a mating thread in a test plate having ahardness HB 110 – 130, thickness equal to the nominaldiameter, with a drive speed not over 30 rpm in a holewhose diameter is given in the following table.During this test the drive torque shall not exceed themaximum values given in the table.

3 2.7 0.9 1.5

4 3.6 2.1 3.4

5 4.5 4.2 7.1

6 5.5 7.2 12

8 7.4 17 28

Nominalthread

diameterd

Test plate

Thickness Hole size

mm.Tolerance H9

mm.

Maximum Minimum

drive torque breaking torque

Nm Nm

M3

M4

M5

M6

M8


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COMMON STANDARDS


DRILLING SCREWS:MECHANICAL PROPERTIES AND PERFORMANCE

SteelsCasehardening steels or heat treatable steel.

Torsional testThe sample screw shall be securely clamped by suitablemeans with at least two full threads projecting above theclamping device, and at least two full threads exclusiveof point, held within the clamping device.By means of a suitably calibrated measuring device,torque shall be applied to the screw until failure of the

screw occurs. The torque required to cause failure shallbe equal to or exceed the minimum breaking torquespecified in the table.

Ability to forming the mating threadThe screw shall, (without permanent deformation of itsown thread), form a mating thread in a test plate havinga hardness HV 110 – 165.The plate thickness and the rotational speed are given inthe following table:

Embrittlement

For these screws there is a risk of failure due to hydrogenembrittlement, especially if they are electroplated.Therefore process investigation shall be conductedaccording to ISO 15330.

In the case of electroplating, hydrogen embrittlement relief treatment in accordance with ISO 4042 shall be applied.Non electrolytic applied coating are preferred.

0.7 + 0.7 = 1.4 150 1 800 – 2 500 3 1.5

1 + 1 = 2 150 1 800 – 2 500 4 2.81.5 + 1.5 = 3 250 1 800 – 2 500 5 4.7

2 + 2 = 4 250 1 800 – 2 500 7 6.9

2 + 3 = 5 350 1 000 – 1 800 11 10.4

2 + 3 = 5 350 1 000 – 1 800 13 16.9

Nominal

thread

diameter

Designation

N°

Plate thickness

mm

Minimum

torsional

strength

Nm

Drilling parameters

Axial Rotational speed of Test

Force screw under load duration

N min.–1 s

ST 2.9 4

ST 3.5 6ST 4.2 8

ST 4.8 10

ST 5.5 12

ST 6.3 14


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COMMON STANDARDS

UNI 3740-4(EXTRACT)

MECHANICAL PROPERTIES OF NUTS

This standard specifies the mechanical properties for nuts.It applies to nuts:• with nominal thread diameters, d, from 3 mm. up to

and including 30 mm. for coarse thread and from 8mm. up to 30 mm. for fine pitch thread

• with triangular ISO thread according ISO 68-1• with diameter/pitch combinations according to ISO 261

(coarse thread and fine pitch thread)• with thread tolerances 6H according to ISO 965/1 and

ISO 965/2

• with dimensional tolerances according to ISO 4759/1• with widths across flats as specified in ISO 272 or

greater• manufactured in steel

It does not specify requirements for such properties as:ability to withstand temperature above +300°C, or below–50°C.

The property classes 5S, 6S end 8G have only hardness limits.The property classes 6, 8 end 10 have hardness limits and proof loads.

5S* 6* - 0.50 - 0.110 0.1506S* 8* - 0.58 0.25 0.060 0.150

8G♦ 10♦ 0.15 0.58 0.30 0.048 0.058* Free cutting steel is allowed; in this case the following maximum lead, phosphorus and sulphur

contents are permissible:Pb ≤ 0.35% P ≤0.12% S ≤ 0.34%

♦ When agreed with the user, the use of free cutting steel is allowed; in this case the limit for thelead is the following:

Pb ≤ 0.35%

Property class


C Mn P S

min. max min. max. max.

LIMITS OF CHEMICAL COMPOSITION

5S 6 150 302 79 - 306S 8 188 302 89 - 30

8G♦ 10♦ 272 353 - 26 36

♦ Nuts of this property class shall be hardened and tempered.

Property class

Vickers Hardness Rockwell Hardness

HV HRB HRC

min. max. min. min. max.

HARDNESS VALUES

PROOF LOAD VALUES

Property classStress under

proof load SpN/mm2

6 6008 80010 1000


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COMMON STANDARDS

DIN 267-4(EXTRACT)

MECHANICAL PROPERTIES OF NUTS

This standard specifies the mechanical properties of nutswhich have to withstand specified proof loads• with nominal thread diameters up to and including

39 mm• with ISO metric thread as defined in DIN 13 Part 13• with thread tolerances 6H in accordance with DIN 13

Part 15• with nominal heights not less than 0,8 D (including the

normal countersink on the thread)

• with width across flats or external diameters not lessthan 1,45 D and of other nuts where reference is madeto this standard. It does not specify requirements forsuch properties as:

Ability to withstand temperature above +300°C, or below–50°C.

8 0.58 0.30 0.060 0.150

10 0.58 0.30 0.048 0.058

Property class


C Mn P S

max. min. max. max.


8 800 302 3010 1000 353 36

Property class


Proof load Vickers Rockwellstress hardness hardness

Sp HV HRC

N/mm2

max. max.



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COMMON STANDARDS


MECHANICAL PROPERTIES OF FASTENERS

NUTS WITH SPECIFIED PROOF LOAD VALUES

COARSE THREAD

This International Standard specifies the mechanicalproperties of nuts with specified proof load values whentested at room temperatureProperties will vary at higher and lower temperature.It applies to nuts:• with nominal thread diameters up to and including 39 mm• with triangular ISO thread in accordance with ISO 68-1• with diameter/pitch combinations according to ISO 261

(coarse thread)• with thread tolerances 6H according to ISO 965-1 and

ISO 965-2

• with specific mechanical requirements• with widths across flats as specified in ISO 272 or

equivalent• with nominal heights greater than or equal to 0,5D• made of carbon steel or low alloy steel

It does not specify requirements for such properties as:Ability to withstand temperature above +300°C, or below–50°C.

6 6.8 ≤ 39 ≤ 39 -

8 8.8 ≤ 39 ≤ 39> 16

≤ 399 9.8 ≤ 16 - ≤ 1610 10.9 ≤ 39 ≤ 39 -12 12.9 ≤ 39 ≤ 16 ≤ 39

Propertyclass of

nut

Mating bolts NutsStyle 1 Style 2

Property class Diameter range Diameter rangemm. mm.

DESIGNATION SYSTEM FOR NUTS WITH NOMINAL HEIGHTS ≥ 0,8D

04 400 38005 500 500

Propertyclass of

nut

Nominal stress Actual stressunder proof load under proof load

N/mm2 N/mm2

DESIGNATION SYSTEM AND STRESSES UNDER PROOF LOAD FOR NUTS WITH NOMINAL HEIGHTS ≥ 0,5D BUT < 0,8D

6 0.50 - 0.060 0.15004 8 9 0.58 0.25 0.060 0.15005 10 0.58 0.30 0.048 0.058

12 0.58 0.45 0.048 0.058

Propertyclass


C Mn P S

max. min. max. max.



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> ≤- 44 77 1010 1616 39

380 188 302 NQT 1)

Diametermm.

Property class 04Thin nuts

Vickers hardnessHV

min. max.

Stress under proof loadSp

N/mm2state


> ≤- 44 77 1010 1616 39

500 272 353 QT 2)

Diametermm.

Property class 05

Thin nutsVickers hardnessHV

min. max.


N/mm2state

> ≤- 44 77 1010 1616 39

600 150 302 NQT 1)670 150 302 NQT 1)680 150 302 NQT 1)700 150 302 NQT 1)720 170 302 NQT 1)

Diameter

mm.

Property class 6Style 1

Vickers hardnessHVmin. max.

Stress under proof loadSpN/mm2

state

> ≤- 44 77 1010 1616 39

800 180 302 NQT 1)855 200 302 NQT 1)870 200 302 NQT 1)880 200 302 NQT 1)920 233 353 QT 2)

Diametermm.

Property class 8Style 1Vickers hardness

HVmin. max.


N/mm2state

> ≤16 39 890 180 302 NQT 1)

Diametermm.

Property class 8Style 2Vickers hardness

HVmin. max.


N/mm2state

1) NQT = Not quenched or tempered2) QT = Quenched and tempered


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> ≤- 44 77 1010 1616 39

900 170 302 NQT 1)915 188 302 NQT 1)940 188 302 NQT 1)950 188 302 NQT 1)920 188 302 NQT 1)

Diametermm.


Vickers hardnessHV

min. max.


N/mm2state

> ≤- 44 77 1010 16

16 39

1 0401 0401 040 272 353 QT 2)1 050

1 060

Diametermm.


Vickers hardnessHV

min. max.


N/mm2state

> ≤- 44 77 1010 16

16 39

1 1501 1501 160 272 353 QT 2)1 190

1 200

Diametermm.


Vickers hardnessHV

min. max.


N/mm2state

> ≤- 44 77 1010 16

1 1401 140 295 353 QT 2)1 1401 170

Diametermm.


Vickers hardnessHV

min. max.


N/mm2state



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COMMON STANDARDS


MECHANICAL PROPERTIES OF FASTENERS

NUTS WITH SPECIFIED PROOF LOAD VALUES

FINE PITCH THREAD

This international standard specifies the mechanicalproperties of nuts with specified proof load values whentested at room temperature.Properties will vary at higher and lower temperature.It applies to nuts:• with nominal thread diameters, d, from 8 mm. up to

and including 39 mm (fine pitch thread)• with triangular ISO thread in accordance with ISO 68-1• with diameter/pitch combinations according to ISO 261

(fine pitch thread)

• with thread tolerances 6H accordance with ISO 965-1and ISO 965-2

• with specific mechanical requirements• with widths across flats as specified in ISO 272 or

equivalent• with nominal heights greater than or equal to 0,5D• made of carbon steel or low alloy steel

It does not specify requirements for such properties as:ability to withstand temperature above +300°C, or below–50°C.

8 8.8 d ≤ 39 d ≤ 39 d ≤ 16

10 10.9 d ≤ 39 d ≤ 16 d ≤ 39

12 12.9 d ≤ 16 - d≤ 16

Propertyclass of nut

Mating bolts NutsStyle 1 Style 2

Property class Diameter range Diameter rangemm. mm.

DESIGNATION SYSTEM FOR NUTS WITH NOMINAL HEIGHTS ≥ 0,8D

04 400 380

05 500 500


Nominal stress Actual stress underunder proof load proof load

N/mm2 N/mm2

DESIGNATION SYSTEM AND STRESS UNDER PROOF LOADS FOR NUTS WITH NOMINAL HEIGHTS ≥ 0,5D BUT < 0,8D

04 8 0.58 0.25 0.060 0.150

05 10 0.58 0.30 0.048 0.058

12 0.58 0.45 0.048 0.058



C Mn P S

max. min. max. max.



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≥ 8 ≤ 16

> 16 ≤ 39380 188 302 NQT 1)

Diametermm.


Vickers hardnessHV

min. max.


N/mm2state

≥ 8 ≤ 16

> 16 ≤ 39

Diametermm.


Vickers hardnessHV

min. max.


N/mm2state

≥ 8 ≤ 16

> 16 ≤ 39890 195 302 NQT 1)

Diametermm.


Vickers hardnessHV

min. max.


N/mm2state

≥ 8 ≤ 10

> 10 ≤ 16

> 16 ≤ 33

> 33 ≤ 39

955 250 353 QT 2)

955 250 353 QT 2)

1 030 295 353 QT 2)

1 090 295 353 QT 2)

Diametermm.


Vickers hardnessHV

min. max.


N/mm2state


500 272 353 QT 2)


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≥ 8 ≤ 16

> 16 ≤ 391 200 295 353 QT 2)

Diametermm.


Vickers hardnessHV

min. max.


N/mm2state

≥ 8 16

> 16 ≤ 39

1 100295 353 QT 2)

1 110

Diametermm.


Vickers hardnessHV

min. max.


N/mm2state

≥ 8 ≤ 10

> 10 ≤ 16

> 16 ≤ 39

1 055 250 353 QT 2)

1 055 250 353 QT 2)

1 080 260 353 QT 2)

Diametermm.


Vickers hardnessHV

min. max.


N/mm2state



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COMMON STANDARDS

DIN 267-24(EXTRACT)

MECHANICAL PROPERTIES OF NUTS(HARDNESS CLASS)

This standard specifies the mechanical properties of nutsand similar fasteners not under tensile stresses in the rangefrom 10 up to and including 200 mm. thread diameterwhich are made of carbon steel or free cutting steel.

It does not apply to fasteners requiring special propertiessuch as:• specified tensile stresses• weldability• corrosion resistance• ability to withstand temperatures above + 250° C or

below –50° C

14H 0.50 0.12 0.35 0.34

Property class


C P Pb S

max. max. max. max.


14H 140 215 133 204

Property class


Vickers Brinellhardness hardness

HV HBmin. max. min. max.



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COMMON STANDARDS

TABLE A

PREVAILING TORQUES

FOR RINGS - ELASTIC STOP

M 20 1 14 4

M 25 1.5 22 6

M 30 1.5 34 9

M 35 1.5 54 12

M 40 1.5 70 15

M 45 1.5 94 24

M 50 1.5 116 32

M 55 2 140 40

M 60 2 162 48

M 65 2 185 58

M 70 2 208 66

M 75 2 232 75

M 80 2 255 84

M 85 2 278 92

M 90 2 300 100

M 95 2 324 108

M100 2 346 118

Thread PitchPrevailing Torque Nm

1° assembly max. 5° removal min.


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LubricantThe nuts are delivered with an appropriate lubrication, inorder to meet the specified performance requirements.The lubricant do not cause any irritation on the skin, noremits an unpleasant odour.Nuts supplied with a lubricant are clean and dry to thetouch.If the lubricant is subsequently removed by the customer,the mechanical and performance properties of the nutchange.

Prevailing torque testWith reference to DIN 267-15 the prevailing torque test isconducted as follows.The prevailing torque test is conducted at roomtemperature using a torque wrench and with the aid of adevice for measuring the clamping load on the bolt.A test bolt, together with a test washer, is inserted in thedevice for measuring the clamping load on the test bolt.The nut to be tested is then assembled on the bolt so thatat least 2 full bolt threads protrude through the nut. Nuttightening may be either manual using a torque wrench or

using a torque-sensing power device. The maximumprevailing torque occurring while the nut is beingadvanced through the next 360° of nut rotation ismeasured. This torque shall not exceed the first fixingprevailing torque value specified in the table enclosed.Tightening is continued until the nut is seated against thetest washer. The length of the test bolt shall be such thatseating of the nut occurs when a length equivalent to fourto seven thread pitches of the bolt protrudes through thetop of the nut, measured from the end of the bolt. The nutshall then be tightened until a tensile load equal to theclamp load, as specified in the table, is developed in the

bolt. The test washer shall be prevented from turning.

The nut is then slackened until the tensile load in the bolthas been reduced to zero. The minimum prevailing torqueoccurring while the nut is being slackened through thenext 360° of rotation is measured. This torque shall be notless than the first fixing prevailing torque value as specifiedin table.The nut is then reassembled and removed four more times.On each assembly, the nut shall be advanced sufficientlyto allow a length equivalent to four to seven tread pitchesto protrude through the nut, without applying a test clamp

load. On each removal, the prevailing torque elementshall be disengaged from the bolt thread.During the fifth removal, the minimum prevailing torqueoccurring while the nut is being slackened through the first360° of rotation is measured. This torque shall be not lessthan the prevailing torque value specified in table. Inaddition, at no time during these four additional refixingsand removals shall the torque exceed the maximum firstfixing prevailing torque value.To avoid overheating of the assembly, sufficient time shallelapse between the torque application cycles. The speedof installation and removal of the nut shall not exceed 30

min – 1 and shall be continuous and uniform.A property class in accordance with ISO 898-1 whichcorresponds with that assigned to the nut shall be chosenfor the test bolt, e.g. nut: 8; bolt: 8.8. The surface finish of the bolt shall also correspond with that of the nut,normally electroplated in accordance with ISO 4042.Where nuts with a protective coating other than zinc orphosphate are to be tested, a bolt with a zinc-phosphateand oiled finish shall be used. In referee tests the nut andbolt shall have the same surface finish. A new test boltshall be used for testing each nut.

DIN 267-15(EXTRACT)

CLAMPING FORCES AND PREVAILING TORQUES

FOR KLOCK AND ELASTIC STOP NUTS


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M 3 0.5 2190 3130 - - - 0.43 0.12 0.08 0.60 0.15 0.10

M 4 0.7 3820 5470 - - - 0.90 0.18 0.12 1.20 0.22 0.15

M 5 0.8 6170 8850 - - - 1.60 0.29 0.20 2.10 0.35 0.24

M 6 1 8700 12500 - - - 3 0.45 0.30 4 0.55 0.40

M 8 1.25 15900 22800 1 17000 24400 6 0.85 0.60 8 1.15 0.80

M10 1.5 25300 36100 1.25 26600 38100 10.50 1.50 1 14 2 1.40

M12 1.75 36700 52500 1.5 42300 62100 15.50 2.30 1.60 21 3.10 2.10

M14 2 50000 71600 1.5 54400 78000 24 3.30 2.30 31 4.40 3

M16 2 68200 97500 1.5 72700 104000 32 4.5 3 42 6 4.20

M18 2.5 86200 119000 1.5 97500 134000 42 6 4.20 56 8 5.50

M20 2.5 110000 152000 1.5 122000 169000 54 7.50 5.30 72 10.50 7

M22 2.5 136000 189000 1.5 150000 207000 68 9.50 6.50 90 13 9

M24 3 159000 220000 2 172000 239000 80 11.50 8 106 15 10.50

M27 3 206000 286000 2 223000 309000 94 13.5 10 123 17 12

M30 3.5 253000 350000 2 280000 386000 108 16 12 140 19 14

M33 3.5 312000 432000 2 343000 474000 122 18 14 160 21.50 16.50

M36 4 368000 509000 3 389000 538000 136 21 16 180 24 17.50

M39 4 440000 608000 3 463000 641000 150 23 18 200 26.50 19.5

Thread CoarsePitch

FinePitch

Clampingforce

N

Property class

8 10

Clampingforce

N

Property class

8 10

Prevailing TorqueNm

Property class Property class8 10

First First Fifth First First FifthAssemb. Removal Removal Assemb. Removal Removal

max. min. min. max. min. min.


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COMMON STANDARDS

UNI 3740-6(EXTRACT)

FASTENERS: PROTECTIVE COATINGS

The standard specifies the general technical prescriptionsfor the following protective coating on threadedfasteners.- Phosphate coatings- Organic coatings- Mechanical coatings

It can be applied on other threaded or non-threadedfasteners, like washers and pins.

PHOSPHATE COATINGS

Designation systemThe designation system is defined by the followingsymbols:Fe: base metal followed by an oblique barFAR: zinc anti-corrosion phosphateFAG: anti-seizure manganese phosphateZn: zinc (or zinc-iron)Mn: manganese (or manganese-iron)Possible number: nominal coating thickness expressedin mm.

Designation example- Fe/FAR Zn 6It means zinc (or zinc-iron) anti-corrosion phosphate onsteel base; nominal coating thickness of 6 m.

PerformancesPhosphate coatings are usually applied to improve theanti-corrosion performances of the steel surface.

They are made of a tiny crystalline, strongly sticking tothe support, dent coat.Sizes and morphological structure of crystallines definesurface roughness; friction coefficient in screwing isgenerally influenced.The phosphate coating alone is defined by lowprotecting performances, because of its porous structure.Unless different agreements between customer andproducer, it must be soaked with oil.

Thickness and mass of phosphate coatingThe most reliable evaluation is the one referred tophosphate coating specific mass, it is expressed in gramsof coat per square metre of ferrous surface.That measure must be used in case of complaint. Coatingthickness measures with magnetic or electric methods,give results that can be slightly significant.They are suggested only to general check.

Fe/FAR Zn 3 Zinc phosphate 3 a 5 6Fe/FAR Zn 6 Zinc-iron phosphate > 8 24Fe/FAG Mn 7 Manganese-iron phosphate > 10 16

* The nominal thickness is obtained dividing by 1,4 the mass of the coating

Designation Coating nature Coating massg/m2 *

Exposition timein salt spray

hmin.

CORROSION RESISTANCE (OILED COATS)


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Performances of deembrittlement treatmentPhenomena of hydrogen embrittlement can especiallyexist in acid pickling. During zinc phosphate (because of the lower acidity of bathes), they generally don’t getremarkable intensity; on the contrary manganesephosphate in this case verges to be more dangerous.Whenever the material nominal minimum tensile strength

Rm is higher or equal to 1 200 N/mm2 (o similar) can beasked the deembrittlement treatment, and that must bespecified on draw or in ordering. In this case thedeembrittlement treatment can be carry out by heating infurnace, then followed by a cooling at room temperature,as specified in prospect, or staying 120h at roomtemperature.

Temperatures higher than 110 °C are not allowed, toavoid phenomena of chalking of phosphate coat (only

zinc-calcium phosphate allows higher temperature,until 150 °C).

>1 200 N/mm2 8 110

Minimum tensile strength

Rm

Permanenceh

min.

Temperature°C

Deembrittlement treatment

DEEMBRITTLEMENT TREATMENT


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GeneralityThis section defines the technical prescriptions aboutchemical anti-corrosion coatings mainly made of zincand other anodic materials, in comparison with supportmetal and made of polymeric organic binders andchromates.These coatings are known with different commercialnames (for example “DACROMET”).These coatings are especially recommended for fastenerswith tensile strength Rm higher or equal to 1040 N/mm2,

because they don’t produce hydrogen embrittlement.

Designation systemDesignation system is defined by the following symbols:Fe: base metalAC: chemical anti-corrosion coating, made of chromatesmetals and polymeric organic bindersACL: lubricant chemical anti-corrosion coating, made of metals, chromates and polymeric organic binders, with acarbonic fluorine polymer.5: nominal thickness of 5 mm (ordinary class) with aminimum specific mass of 20 g/m2

8: nominal thickness of 8 mm (extraordinary class) witha minimum specific mass of 32 g/m2.

Designation example- Fe/AC 5It means chemical anti-corrosion coating on steel, with anominal thickness equal to 5 m, in ordinary class.

PerformancesThe coating performances are defined by the followingproperties: appearance, thickness, corrosion resistance,adhesion (evaluated as adhesion to thermic stress).

AppearanceCoating must be silver grey coloured, half dull (in case of no post-treatment), homogeneous and uniform on all thesurface.Little dents and light possible exceed of material deposit

are allowed, on condition that check with the gageremains possible.

ThicknessReferring to thickness, coating can be divided in twoclasses:Ordinary class: minimum thickness 5 mm (nominal 5 mm)Extraordinary class: minimum thickness 8 mm (nominal 8 mm)Coating must not compromise screwing, therefore it’simportant the choice of the threaded tolerance position,referring to the recommended thickness, specified by thedrawing or on ordering.

Salt spray corrosion resistanceReferring to the process coating, significant surface is allthe sample surface, except concavities.

ORGANIC COATINGS

Fe/AC 5 600

Fe/ACL 5 600

Fe/AC 8 1000

Fe/ACL 8 1000

Designation

Time without red corrosion productson significant surface

hmin.

CORROSION RESISTANCE


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MECHANICAL COATINGS

GeneralityMechanical coating means applying protective coating,generally made of Zn, Sn, or Al individually or combinedput on the surface, and used as dust in checkedgranulometry water suspension, in a mechanical longrandom pressure action, pressed on details in definedbarrel, produced by mixing spheres of particular sizesand chemical catalyst.Mechanical coating is especially indicated as protectingcoating for high strength fasteners with a tensile strength

Rm higher or equal to 1040 N/mm2, since it doesn’tproduce hydrogen embrittlement.

Designation systemDesignation system is defined by the following symbols:Fe: base metal followed by a oblique barM: mechanical deposition of metallic coatingChemical symbols of coating element: example Zn o Sno Al. The sequence of two symbols of metals means thecoating is made of metallic layers in reference to theapplication order specified in designation.8, 10, 12, 15: nominal values of coating thickness,

expressed in mm, in case of only one layer; or the valueof the total layers thickness of the coating.

c: converting coating made of chromate materials1 e 2: converting coating classes made of chromatematerialsA, B, C, D: kind of converting coating made of chromatematerials *.PerformancesCoating performances are defined by the followingproperties: appearance, thickness, corrosion resistance,adhesion.

AppearanceMechanical coating, without chromate conversion, isdifferently coloured in reference to the coating metal;however its appearance is silvery, from dull to half-bright, homogeneous and uniform on all the surface.After chromate conversion, it gets the typical appearanceof the same.

ThicknessCoating must not compromise screwing.

Salt spray corrosion resistance

Referring to the process coating, significant surface is allthe sample surface, except corners.

* Subject to agreement between customer and producer, conversion coatings made of chromate materials designed byB, with a typical appearance “transparent and iridescent” and D, with a typical appearance “olive green and brown andbronze shades” and its corrosion resistance can be applied.

Fe/M Zn 8c1AFe/M Zn 12c1AFe/M Zn 20c1AFe/M Zn 8c2CFe/M Zn 12c2CFe/M Zn 20c2C

Transparent, light

with blue reflexes

Iridescent yellow

728 96

120144

72 192216

Designation Typicalappearance

Time without whitecorrosion products on

significant surfaceh

min.

Time without redcorrosion products on

significant surfaceh

min.

ZINC COATING


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COMMON STANDARDS


FASTENERS: ELECTROPLATED COATINGS

The following prescription conforms to the contents of ISO 4042, and concerns the electroplating of threaded

fasteners, but it may also be applied to other threadedparts and non-threaded parts such as washers and pins.

A2A Fe/Zn 5c1AA2B Fe/Zn 5c1BA2C Fe/Zn 5c2CA2D Fe/Zn 5c2DA2R Fe/Zn 5BkA3A Fe/Zn 8c1AA3B Fe/Zn 8c1BA3C Fe/Zn 8c2CA3D Fe/Zn 8c2DA3R Fe/Zn 8BkA4A Fe/Zn 12c1AA4B Fe/Zn 12c1B

A4C Fe/Zn 12c2CA4D Fe/Zn 12c2DA4R Fe/Zn 12Bk

A 6 24B 12 36C 48 72D 72 96Bk 12 -A 6 48B 24 72C 72 120D 96 144Bk 24 72A 6 72B 24 96

C 72 144D 96 168Bk 24 96

5

8

12

PROTECTION PERFORMANCE OF ZINC

Designation codesfor coatings

Other possibledesignation

Nominal coat.thickness

µmChromate White corrosion Red rust

h h

Salt spray resistance

1A Clear Transparent, clear, sometimes with a bluish tingeB Bleached Transparent with slight iridescence

2 C Iridescent Yellow iridescentD Opaque Olive green shading to brown or bronzeBk Black Black with slight iridescence

DESIGNATION OF CHROMATE TREATMENTS

Class Designation Type Typical appearance


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DESIGNATION CODE

The following code system is given for electroplated coatings:

X Y Z

where

X : coating metal Y : minimum coating thickness Z : Finish and chromate treatment

Zn Zinc A

Cu Copper C

Ni Nickel E

CuNi Copper-Nickel G

ZnNi Zinc-Nickel PZnCo Zinc-Cobalt Q

ZnFe Zinc-Iron R

COATING METAL / ALLOY

Symbol Elements Designation X

No coating thickness required - 0

5 2 + 3 28 3 + 5 3

12 4 + 8 4

COATING THICKNESS / DESIGNATION

One coating metals Two coating metals Designation Yµm min. µm min.

Transparent, clear A

Transparent with slight iridescence ( bleached ) BYellow iridescent C

Olive green brown D

Black R

FINISH AND CHROMATE TREATMENT

Typical appearance Designation Z


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AGRATI GROUP(EXTRACT)

SURFACE COATING BEHAVIOUR

1000 Dacroblack 15 12µ Incorporated Black Yes 800 1000 0.12 ÷ 0.18 A A A

1000 Zinc pl. + Dorreltech B17 12µ Incorporated Silver grey Yes 800 1000 0.08 ÷ 0.14 A B C

1000 Deltatone / Dorreltech B17 14 µ Incorporated Silver grey Yes 700 1000 0.08 ÷ 0.14 A A A

1000 Dacromet 320 B 8µ No Silver grey Yes 200 1000 0.15 ÷ 0.25 A A A

1000Dacromet 320 B 5µ

T.n.T. Blue Silver grey

Yes 200 1000 0.08 ÷ 0.14 A A Alubricatedor green + possible

or colour less colour

1000 Dacromet 500 B 8µ Incorporated Silver grey Yes 200 1000 0.12 ÷ 0.18 A A A

1000 Dacromet plus L 8µ Incorporated Silver grey Yes 200 1000 0.08 ÷ 0.14 A A A

600 Dacromet 320 A 5µ No Silver grey Yes 200 600 0.15 ÷ 0.25 A A A

600Dacromet 320 A 5µ

T.n.T. Blue Silver grey

Yes 200 600 0.08 ÷ 0.14 A A Alubricated

or green + possible

or colour less colour

600Dacromet 320 A 5µ

Luberstone Silver grey Yes 200 600 0.05 ÷ 0.08 A A Alubricated

600 Dacromet 500 A 5µ Incorporated Silver grey Yes 200 600 0.12 ÷ 0.18 A A A600 Zinc plating + Finigard 105 12µ Incorporated Yellow Yes 200 600 0.12 ÷ 0.18 A B C

600 Zinc plating + Zinthum 12µ Incorporated Black Yes 200 600 0.12 ÷ 0.18 A B C

600 Zinc plating + Lanthane 300 12µ Incorporated Clear blue Yes 200 600 0.12 ÷ 0.18 A B C

600 Zinc plating + Ludogen 12µ Incorporated Yellow Yes 200 600 0.12 ÷ 0.18 A B C

480 Zinc nichel 8µ T.n.T. Yellow Yes 240 4800.12 ÷ 0.18

A B Cor others

400 Deltatone / Deltaseal GZ 12 µ Incorporated Silver grey Yes 288 400 0.08 ÷ 0.14 A A A

400Deltatone / Deltaseal GZ black

Incorporated Dull black Yes 288 400 0.08 ÷ 0.14 A A A12 µ

360 Zinc pl. + Deltacoll GZ 25µ Incorporated Clear blue Yes 120 360 0.08 ÷ 0.14 A B Cor black

312 Zinc iron 5µ T.n.T. Black Yes 120 3120.08 ÷ 0.14

A B Cor others

288 Deltatone 10µ T.n.T. Silver grey Yes --- 288 0.08 ÷ 0.14 A A A

288 Zinc plating 12µ No Olive green -- 96 288 0.15 ÷ 0.30 A B C

288 Mechanical zinc plating 12µ T.n.T. Olive green -- 96 2880.08 ÷ 0.14

A B Cor others

240 Zinc plating + Deltacoll GZ 13µ IncorporatedClear blue

Yes 120 240 0.08 ÷ 0.14 A B Cor black

240 Zinc plating 15µ No Yellow -- 72 240 0.15 ÷ 0.30 A B C

240 Zinc plating 15µ T.n.T. Yellow -- 72 2400.08 ÷ 0.14

A B Cor others

Index saltspray

resistancehrs

plating description andminimum thickness

Lubrication Appearance Thermalshock

salt spray resistancehrs

Property classvs. hydrogen (*)Friction

coefficentµwhite

productshrs

redproducts

hrs≤ 8.8 10.9 12.9


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192 Zinc plating 8µ No Olive green -- 96 192 0.15 ÷ 0.30 A B C

192 Mechanical zinc plating 8µ T.n.T. Olive green -- 96 1920.08 ÷ 0.14

A B Cor others



A B C

or others168 Mechanical zinc plating 12µ T.n.T. Yellow -- 72 168

0.08 ÷ 0.14A B C

or others



A B Cor others

144 Mechanical zinc plating 8µ T.n.T. Yellow -- 72 1440.08 ÷ 0.14

A B Cor others

144 Zinc plating 15µ No Clear blue -- 6 144 0.15 ÷ 0.30 A B C

144 Mechanical zinc plating 15µ T.n.T. Clear blue -- 6 1440.08 ÷ 0.14

A B C

or others96 Zinc plating 8µ No Black -- 24 96 0.15 ÷ 0.30 A B C

96 Mechanical zinc plating 8µ T.n.T. Black -- 24 960.08 ÷ 0.14

A B Cor others


96 Zinc plating 12µ T.n.T. Clear blue -- 6 960.08 ÷ 0.14

A B Cor others


A B Cor others


72 Zinc plating 8µ T.n.T. Clear blue -- 6 720.08 ÷ 0.14

A B Cor others


A B Cor others

72 Phosphatizing ZN 8µ Yes Grey black NA --- 72 0.10 ÷ 0.16 A A1 A1

24 Phosphatizing ZN 6µ Yes Grey black NA --- 24 0.10 ÷ 0.16 A A1 A1

16 Phosphatizing MN Yes Grey black NA --- 16 0.08 ÷ 0.14 A A1 A1

8 Microphosphatizing ZN/CA 3µ Yes Grey black NA --- 8 0.08 ÷ 0.14 A A1 A1

Index saltspray

resistancehrs

plating description andminimum thickness

Lubrication Appearance Thermal

shock

salt spray resistancehrs

Property classvs. hydrogen (*)Friction

coefficentµwhite

productshrs

redproducts

hrs≤ 8.8 10.9 12.9

( * ) A = Precaution not neededA1 = Precaution only with cleaning operationsB = Baking is requiredC = Application excludedNA = Not applicable

And moreover :- Copper plating- Nickel plating- Brass plating- Tin plating

AGRATI GROUP(EXTRACT)


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COMMON STANDARDS


FASTENERS – ACCEPTANCE INSPECTION

This International Standard is applicable to bolts, screws,studs, nuts, pins, washer, blind rivets and other relatedfasteners not intended for high volume machine

assembly, special-purpose applications or speciallyengineered applications requiring greater in-processcontrol and lot traceability.

TERMS AND DEFINITIONS

Sample size: NNumber of fasteners in a sample.

Acceptance number : AC

Maximum number of nonconformities of the samecharacteristic in any given sample which, whenexceeded, causes the lot to be rejected.

Acceptable quality level: AQLQuality level in a sampling plan corresponding to a highprobability of acceptance.Note: In this International Standard, the probability is

greater than or equal to 95%.

Width across flats 1 1 1.5 1

Width across coners 1 1 1.5 1

Nut height 1 - -

Width of slot 1 - 1.5 1

Depth of slot 1 - 1.5 1

Recess penetration 1 - 1.5 1

Socket, GO gauge 1 - - -

Socket, NO GO gauge 1 - - -

Configuration under head 1 - - 1

GO thread gauge 1 1 - 1

NO GO thread gauge 1 1 - 1

Major diameter - - 2.5 1

Geometric tolerances 1 1 2.5 1

All others 1.5 1.5 2.5 1.5

Nonconforming fasteners 2.5 2.5 4 2.5

DIMENSIONAL CHARACTERISTICS OF THREADED FASTENERS

Dimensional characteristicsBolts, screws andstuds of grades

A and B

Nuts of grades Aand B

Self-tapping screws

All thread-formingscrews, self-drilling

screws and chip-boardscrews

Product group

AQL

DIMENSIONAL CHARACTERISTICS OF PLAIN WASHERS

Dimensional characteristicsProduct grade A

AQL

Hole diameter 1Outside diameter 1.5All others 2.5


34/34

191

AQL

EXAMPLES OF SAMPLING PLANS

AC 0.65 1.0 1.5 2.5 4.0

N

0 8 5 3 - -1 50 32 20 13 82 125 80 50 32 203 200 125 100 50 324 315 200 125 80 505 400 250 160 100 -

6 - 315 200 125 807 - 400 250 160 1008 - - 315 200 12510 - - 400 250 16012 - - - 315 20014 - - - 400 25018 - - - - 31522 - - - - 400

CHARACTERISTICS OF THREADED FASTENERS, EXCEPTING DIMENSIONAL CHARACTERISTICS

Characteristics AQL Reference standards

Mechanical characteristics Non-destructive tests 1)and surface integrity Destructive tests

Chemical composition

Metallurgical characteristics

Functional (performance) characteristics

Coating

Others

1) If non-permitted surface discontinuities (for example, quench cracks) are found during surfacediscontinuity inspection (non-destructive test), regardless of their size, the inspection lot shall be rejected.

0.651.5

1.5

1.5

1.5

1.5

1.5

ISO 898 ISO 3506ISO 2320 ISO 6157ISO 2702 ISO 7085ISO 8839 Etc.

ISO 4042 ISO 10683

MECHANICAL CHARACTERISTICS OF PLAIN WASHERS

AQL

Mechanicalcharacteristic 1)

Carbon o alloy steel Stainless steel Non-ferrous metal

Hardness 0.65 0.65 -

1) Specified in product standards. Other characteristics may be required according to the


Documents

MECHANICAL PROPERTIES OF BOLTS AND SCREWS