Nuts and Bolts Specifications

Bolts are often identified by a number or letter found on its head.

Nuts and bolts are simple things on first glance, but they are full of mysteries. Those mysteries are unraveled as we attend to the various specifications of these common items.

Nut Types

Standard nuts are first classified according by use. Acorn, anchor, cage, castle, coupling, cylinder, finger, flange, hex, jam, kep, lock, nylon insert, pallet, push, round, self-clenching, speed, square, T, U-type, washer, weld and wing are all types of nuts.

Nut Characteristics

Each nut has a set of characteristics that identify it. Those characteristic include type of metal, direction of thread, length of the nut, diameter of the thread channel, size and turn of the threads, diameter and height of the head, style of the head, whether it is SAE or metric and by its finish.

Bolt Types

Bolts are also classified by use. Use specifications include anchor, carriage, elevator, flange, hanger, hexagon, lag, machine, plow, sex (yes, it's a bolt), shoulder, square, structural, stud, T-head, toggle and U-bolts.

Bolt Characteristics

Again, the use does not specify the characteristics of the individual bolt. Specific characteristics for bolts include bolt diameter, Society of Automotive Engineers (SAE) or metric, length, material, head-fitting, head diameter and height, thread size and turn, radius, shank length and run out.

References

• Gizmology: Nuts and Bolts
• Global Spec: Nut Specifications
• Global Spec: Bolt Specifications

Resources

• British Fasteners: Nut and Bolt Specifications