BS4466:

1989

Shape

CodesIn April 2000 a new British Standard, BS8666 the ‘Specification for scheduling, dimensioning, bending and cutting of steel reinforcement for concrete’ was introduced, replacing BS 4466. Although BS4466 is superseded it is still used and is described below for reference purposes.

BS

4466 –

Preferred

Shapes

Method of measurement ofbending dimensions.

Total length of bar (L)measured along centre line.

Method of measurement ofbending dimensions.

Total length of bar (L)measured along centre line.

Shape Code 20A

Shape Code 41A+B+(C)If angles with the horizontalare 45° or less: see note 4.

Shape Code 32A+h

Shape Code 43A+2B+C+(E)If angles with the horizontal are45° or less: see note 4.

Shape Code 33A+2h

Shape Code 51A+(B)-½R-dThis formula is approximate, if R is minimum, use shape 37. If R is greater than 200mm, see note 2 to clause 10 BS 4466 1989.

Shape Code 34A+nWhere the overall dimension of the bob is critical, use shape code 37.

Shape Code 6112(A+B)+12dNeither A nor B are to be less than 12d or 150mm, whichever is the greater, for grade 460 in sizes not exceeding 20 mm nor less than 14d for sizes of 25mm and over. Neither A nor B are to be less than 10d for grade 250 with a minimum value of A and

B of 100mm. See note 3.

Shape Code 35A+2nWhere the overall dimension of eitherbob is critical, do not use this shape code.

Shape Code 62A+(C)If angle with horizontal is 45° or less.See note 4.

Shape Code 37A+(B)-½r-dThis formula is approximate. Where r is greater than the minimum value in table 3 BS 4466 1989, use shape code 51.

Shape Code 822A+3B+18dIf B is greater than 400+2d, see note 2 to clause 10 BS 4466 1989.See note 3

Shape Code 38A+B+(C)-r-2d

BS

4466 –

Non

Preferred

Shapes

Method of measurement ofbending dimensions.

Total length of bar (L)measured along centre line.

Method of measurement ofbending dimensions.

Total length of bar (L)measured along centre line.

Shape Code 39A+0.57B+(C)-1.57dIf B is greater than 400+2d, see note 2 to clause 10 BS 4466 1989

Shape Code 772A+B+20dSee note 3.

Shape Code 42A+B+C+nIf angle with horizontal is 45° or less.see note 4.

Shape Code 782A+B+C+3dSee note 3.

Shape Code 45A+B+(C)-½r-dIf angle with horizontal is 45° or less.see note 4.

Shape Code 792A+3B+10dNeither A nor B shall be less than 12d or 150mm, whichever is the greater, for grade 460 in sizes not exceeding 20mm nor less than 14d for sizes of 25mm and over. Neither A nor B are to be less than 10d for grade 250 with a minimum value of A and

B of 100mm. See note 3

Shape Code 49A+B+(C)If angle with horizontal is 45° or less. see note 4.

Shape Code 85A+B+0.57 C+(D)-½r-2.57dIf C is greater than 400+2d see note 2 to clause 10 BS 4466 1989.

Shape Code 52A+B+C+(D)-1½r-3d

Shape Code 87C⁄B π (A-d) (L<12m)Where A is the external diameter of helix (in mm) B is the pitch of helix (in mm)C is the overall height of helix (in mm). Where B is greater than A/5 the formula does not apply. There shall be at least two full turns in the helix. Note, unless A is small relative to d, this shape is fabricated in a closed form and pulled to shape on site.

Shape Code 53A+B+C+D+(E)-2r-4d

Custom Shape Shape Code 99All other shapesTo be calculatedA dimensional sketch shall be drawn out over schedule columns A to E. Every dimension that is to allow for

the permissable deviations shall be indicated in parenthesis, otherwise the fabricator is free to choose which dimension shall allow for the tolerance.

Shape Code 54A+B+(C)-r-2d

Shape Code 55A+B+C+D+(E)-2r-4d

Shape Code 65AThese bars will be supplied straight when the radius is greater than that given in table 5 of BS 4466 1989.

Notes

Note 1. r indicates the minimum value in the table 3 BS 4466 1989

Note 2. The dimensions in parenthesis are the free dimensions

Note 3. To avoid separate equations for each steel grade and bending radius, simplified total length formulae are used for shape codes 61, 77, 78, 79 and 82. These formulae are necessarily approximate.

Note 4. The length formula is approximate and when bending angles exceed 45° the length should be calculated more accurately allowing for the difference between the specified overall dimensions and the true length measured along the central axis of the bar or wire. When the bending angles approach 90°, it is preferable to specify shape code 99 with a fully dimensional sketch.

BAR MASS per linear metre (kg/m) :-

50mm: 15.413kg/m 40mm: 9.864kg/m 32mm: 6.313kg/m 25mm: 3.854kg/m

16mm: 1.579kg/m 12mm: 0.888kg/m 10mm: 0.616kg/m 8mm: 0.395kg/m

Table 3. Minimum former radii, bend and hook allowances

Bar Size Grade 250 bars complying with the requirements of BS 4449 (type and grade R) and BS 6744 type S

Bar Size Grade 460 bars complying with the requirements of BS 4449 (type and grade T) and BS 6744 type S

Fabric Size

Sheet Fabric complying with the requirements of BS 4483standard size 4.8m x 2.4m

d r+ n h d r+ n h d r+

6†‡ 12 100 100 6†‡ 18 100 100 5 15

8 16 100 100 8 24 100 100 6 18

10 20 100 100 10 30 100 110 7 21

12 24 100 110 12 36 100 140 8 24

16 32 100 150 16 48 100 180 9 27

20‡ 40 100 180 20‡ 60 110 220 10 30

25‡ 50 130 230 25‡ 100 180 350 12 36

32‡ 64 160 290 32‡ 128 230 450

40‡ 80 200 360 40‡ 160 280 560

50‡ 100 250 450 50‡ 200 350 700

**The use of hooks as end anchorages is not normally necessary with deformed bars.† It should be borne in mind that special precautions such as reducing the speed of bending or increasing the radius of bending may necessary in cold weather. For bending and rebending on site refer to BS 8110.

‡ Non-preferred size for grade 250 bars.

• Non-preferred size for grade 460 bars.

NOTE: These radii are the minimum radii of the formers for material complying with the relevant British standard. Certain design situations may call for larger radii and for these the recommendations in BS 8100 should be followed.

Radius of

bend

ing:-

m

aximum

values

requiring

bendin

g

Bar Size 6 8 10 12 16 20 25 32 40

Radius (m)

2.5 2.75 3.5 4.25 7.5 14 30 43 58

N.B. Bars to be formed to a radius exceeding the above dimensions will be supplied straight.