has a great selection of charts used to identify and explain the wide variety of screws, bolts, nuts, washers and other pieces used for building just about every project you can imagine. Wood screws, machine screws, carriage bolts, lag bolts, square heads, torx, ogee washers and more.
There’s even a section about the grade/strength types of the different materials used for the fasteners. Very handy indeed.
Measuring
There are several different locations on a fastener where one can measure the diameter.
The most commonly used diameters are:
Thread Diameter (T). Also called major diameter.
Shank Diameter (S).
Root Diameter (R). Also called minor diameter.
