Frequently Asked Questions


A hex head cap screw has a washer face, while a hex head machine bolt does not.

The bearing surface is the washer face directly under the head.

Lag screws are available in both hex and square, although hex is more common.

Lag screws have a gimlet point.

Set screws are available in the following points: cup, cone, oval, dog, flat, nylon/brass tip, knurled cup.

The two degrees of angle commonly found are 82 and 100.

Pan Head and Binding Head.

Round, Flat, and Oval are the main head styles available for wood screws.

A type “A” has a sharp point, while a type “B” has a blunt point.


D/C stands for Double Chamfer and is common on hex nuts.

The two major visible differences are Height (thickness) and width across the flats.

The most common shapes for machine screw nuts are hex and square.


The major difference between the two is the outside diameter, but the inside diameter is also different.

A bonded washer consists of a neoprene washer bonded onto a steel, stainless, or aluminum washer.


WorldSource Fasteners has a $25 order min as well as a $2 line min.

Purchase orders can be sent direct to

Please feel free to contact any one of our Technical Sales Representatives at 262-236-9288 for immediate assistance.

Cold heading refers to the forming of metal wire into various shapes while in its “cold” (unheated) state. “Heading,” in short, is forming the head on the bolt. It is the fastest and most economical process used in the working of metal. The shapes are formed by one or more blows from hammers or punches in cavities that conform to the shape of the bolt or screw head.

Hot Forging is also a process for the forming of metal into predetermined shapes except that the material is preheated before it is forged. Bolts are hot-forged rather than cold headed when 1) the material is too large in diameter to be cold worked, 2) small quantity is more economical to run than cold heading, 3) tooling would be simplified.

Shear strength is a transfer rupture. It is opposite from tensile strength in that this latter physical characteristic is caused by longitudinal pull, while shear is caused by push or pull 90 degrees from the axis.

Tensile strength is the most referred to physical characteristic in high temperature and high strength bolting requirements. Tensile strength, basically, is that ultimate strength of a given alloy or products. It is calculated by determining the tensile stress corresponding to the maximum load observed in a tension test. Heat treatment will also increase the tensile strength of many alloys.