Ed's Tech Tip: How to Measure the Length of Different Fasteners

I find that there is often some confusion on the proper way to measure flat head, shoulder and hex or socket head screws. I realize this may be a simple, almost trivial discussion for many, but perhaps worthy of a review. At C.I.S. we continually strive to communicate effectively in order to understand our customers' needs. Insuring that we receive the correct measurements from you, our customers allows us to supply the product you indeed want. If confusion surrounds the measurement of fasteners, it can certainly lead to shipping delays and then the worst of all, production delays.

The following are simple diagrams that will show you how to measure the length and diameter of the fastener.

To measure the length of a shoulder bolt you must only measure from under the head to the end of the shoulder body. Please do not confuse this with the other fasteners and measure the overall length and include the threads.

Please include the diameter of the shoulder when ordering. When measuring a shoulder bolt please be aware that you do not measure the threads or the diameter of them. The threads will be a standard size that corresponds with the shoulder diameter. Example: If the diameter of the shoulder is 5/16 the threads will be 1/4-20. If the diameter of the shoulder is 3/8 the threads would be 5/16-18.

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