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ANSI
American National Standards Institute
The following ANSI standards are dimensional standards and are often used to call out the type of the fastener in engineering prints. They typically start with B18 for fasteners.
Bolts
| Standard |
Fastener Type |
| B18.2.1 |
Hex Bolt, Hex Cap Screw, Hvy Hex Bolt, Square Bolt, Hex Lag Screw, Tap Bolt |
| B18.2.6 |
Hvy Hex Structural Bolt |
| B18.5 |
Carriage Bolt, Ribbed Neck Car Bolt, Elevator Bolt, T-Head Bolt |
| B18.9 |
No. 3 Head Plow Bolt, No.7 Head Plow Bolt |
| B18.10 |
Oval Neck Track Bolt, Elliptic Neck Track Bolt |
| B18.15 |
Eye Bolt |
| B18.6.2 |
Slotted Flat Head Cap Screws, Slotted Round Head Cap Screws, Slotted Fillister Head Cap Screws |
Nuts
| Standard |
Fastener Type |
| B18.2.2 |
Hex Nut, Hex Jam Nut, Hvy Hex Nut, Slotted Nut, Square Nut |
| B18.2.6 |
Structural Hvy Hex Nut |
| B18.6.X |
Wing Nut |
Sockets
| Standard |
Fastener Type |
| B18.3 |
Socket Head Cap Screw, Low Head Socket Cap Screw, Flat Head Socket Cap Screw, Button Head Socket Cap Screw, Socket Shoulder Bolt, Socket Set Screw, Hex Key |
| B18.6.2 |
Square Head Set Screw, Slotted Set Screw |
Screws
| Standard |
Fastener Type |
| B18.6.1 |
Wood Screws - All Head Styles and Drives |
| B18.6.3 |
Machine Screws - All Head Styles and Drives |
| B18.6.4 |
Tapping Screws/Sheet Metal Screws - All Head Styles and Drives, Round Head U-Drive Screws |
Washers
| Standard |
Fastener Type |
| B18.21.1 |
Standard Flat Washer, Type A, Type B |
| B18.22.1 |
Helical Spring Lock Washer, High-Collar Lock Washer, Internal Tooth Lock Washer, External Tooth Lock Washer, Countersunk External Tooth Lock Washer, Internal/External Lock Washer |
Pins
| Standard |
Fastener Type |
| B18.8.1 |
Clevis Pins, Cotter Pins |
| B18.22.1 |
Taper Pins, Dowel Pins, Grooved Pins, Spring Pins |
