Screw thread inserts (STI) require the threaded hole to be inspected prior to inserting the threaded insert or coil. The dimensions and tolerances for the gages used to inspect these threads have been a bit confusing over the past 30 years. 

Screw threads are one of those important elements of mechanical design that are often taken for granted but find usage in critically important applications.

Thread classes for product threads, and by extension the gages used to inspect them, can become a bit of alphabet soup. Some find the requirements confusing.

Pick up any shaft or threaded fastener. How are you going to check it? An outside micrometer is most often the go-to tool for measuring diameters. A height gage or drop indicator could be used to check dimensions between part features, while an optical comparator is a good way to inspect thread forms or measure a groove width.

The basic concept of a thread plug is to provide a quick inspection for machinists and quality inspectors to verify that the threads are within the accepted tolerance so that it interacts with the mating part correctly. 

How do you measure an internal thread on a part? How do you decide what you need?

Kaman’s ThreadChecker™ uses proven inductive technology to provide economical go/no-go thread verification of 100% of your threaded parts.

The term “backlight” has two common meanings. One is a lighting product which is a planar uniform light source; the other is as a silhouetting lighting solution that may use that type of light source.

In today’s demanding manufacturing environment, it is vital that all of your threaded parts are properly inspected with the correct types of thread gages.

The measurement of the depth of thread on an internal thread can be challenging. A quick and accurate way to check thread depth is to modify the go thread plug gage by adding a depth notch or depth step to represent the functional thread depth.