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Types and Uses of Fasteners
Copyright © Texas Education Agency, 2011. All rights reserved.
Copyright © Texas Education Agency, 2011. All rights reserved.
Importance of Fasteners
• They simplify the manufacture of machines and structures.
• They reduce the need for large one piece parts.
• It is normally easier to make less complex components and fasten them together
Copyright © Texas Education Agency, 2011. All rights reserved.
Importance cont.
• They simplify repair of structures and equipment.
• Individual component parts can simply and quickly be separated for inspection, repair, or replacement.
Copyright © Texas Education Agency, 2011. All rights reserved.
They Provide Safety
• Use of fasteners tends to assure that once an assembly is fastened together it will hold together.
• They can also be installed to provide additional support or they be a weak links. (Ex. Shear pins, drive shafts, & breakaway plowshares)
Copyright © Texas Education Agency, 2011. All rights reserved.
B. General types of Fasteners
• Bolts, nuts, and washers
• Screws• Keys• Studs• Pins• Rings• Rivets
• Adhesives• Nails• etc.
Copyright © Texas Education Agency, 2011. All rights reserved.
Specific Types and uses of fasteners
• Bolts: are threaded lengths of steel rod with heads on one end.
• They are used with a nut at the other end and sometimes with a washer as well.
Copyright © Texas Education Agency, 2011. All rights reserved.
American Standard BoltsHexagon or Square Head
• Most have a hexagonal head (6-sided). Older square bolts have a 4- sided head.
• Without a nut they are called cap screws and are screwed into threaded holes.
• Bolts are selected by strength rating, chemical or heat compatibility.
Carriage Bolts
• Most have a round head with a square neck, under the head.
• Carriage bolts are used to fasten wood parts where a smooth finish is required.
Copyright © Texas Education Agency, 2011. All rights reserved.
Bolts
Carriage bolt
Plow bolt
Cap Screw
Hex Bolt
Copyright © Texas Education Agency, 2011. All rights reserved.
Plow Bolts
• Counter sunk, square- neck carriage bolt.
• These have a flat, tapered head that fit into countersunk holes.
• Used when it is necessary for the head to lie flush with the surfaces of the part.
Copyright © Texas Education Agency, 2011. All rights reserved.
Nuts:
• Are flat, usually hexagonal shaped steel pieces with internally cut threads.
Copyright © Texas Education Agency, 2011. All rights reserved.
Castellated & Slotted nuts
• A. These are used when a cotter pin is placed through a hole in the bolt to secure the nit so it cannot come loose.
• Ex: Wheel bearing spindles
Copyright © Texas Education Agency, 2011. All rights reserved.
Nuts
Copyright © Texas Education Agency, 2011. All rights reserved.
Self Locking nuts
• A. Once tightened these nuts stay firmly in place.
• B. They are commonly known as “elastic” or plastic insert nuts.
Copyright © Texas Education Agency, 2011. All rights reserved.
Washers• A. Plain washers: (flat washers) are steel
disks with a hole in the center.
• B. They are used to reduce the stress under the bolt or nut.
• C. They spread a clamping force from the bolt over a larger area to span slots and oversize holes in wood
Copyright © Texas Education Agency, 2011. All rights reserved.
Washers
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Lock Washers
• A. Helical spring washers are made of tough spring steel.
• B. Normally installed under the nut or bolt.
• C. They are used to prevent rotation of the nut.
Copyright © Texas Education Agency, 2011. All rights reserved.
Nails
• Nails are steel rods with a head on one end and usually pointed at the other end.
• They are used primarily to join wood together.
Copyright © Texas Education Agency, 2011. All rights reserved.
Nail size:
• Generally given in terms of “penny”
• “d” indicates the penny size
• Nails are sold by the pound at most hardware stores.
Copyright © Texas Education Agency, 2011. All rights reserved.
Penny SizesNumber per pound
Penny Length (In) Common Box Finish
2d3d4d8d
10d16d20d
11 ¼1 ½
23
3 ¼4
8305783161681066949
80106354732361458471
1315180758430918912190
Copyright © Texas Education Agency, 2011. All rights reserved.
Common Nail
• This is a general all purpose construction nail suitable for framing structures.
• It has a larger diameter than the same size box nail
Copyright © Texas Education Agency, 2011. All rights reserved.
Common Nail
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Box Nail
• Box Nail are used for end nailing and light household use.
• The point is dulled to prevent splitting the wood
Copyright © Texas Education Agency, 2011. All rights reserved.
Box Nails
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Finish Nail
• This is a nail with a small head with a dimple in the center to allow for countersinking with a nail set.
Copyright © Texas Education Agency, 2011. All rights reserved.
Finish Nail
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Duplex Nails
• A duplex nail has two heads on the shank
• It is used to whenever a nail has to be removed.
• Ex when assembling concrete forms
Copyright © Texas Education Agency, 2011. All rights reserved.
Duplex Nail
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Roofing Nails
• Used to secure shingles or roofing to the underlying structure
• They are normally available with either a spiral or helix head shank for extra holding power.
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Roofing Nail
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Screws
• Screws are threaded lengths of steel rod with heads on one end.
• Screw heads may be slotted, cross slotted, square, or hexagonal.
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Types of screws
Copyright © Texas Education Agency, 2011. All rights reserved.
(c) 2006 Texas Trade & Industrial Education UNT in partnership with TEA, Copyright ©. All rights reserved. Building Trades: Fasteners