Gillian Babicz, Associate Editor T he fastener industry is a cost-conscious one. Covering all the bases, from having an original threading standard to investing in equipment, can make the difference between go and no go. The trouble with a screw thread is that it s not a simple element. The tolerances on the gaging involved on making a metric thread and exporting it to Europe can be different than the gaging on the same thread being used in the United States. Cox said the difficulty in interpreting specifications, to make the fasteners correctly, is an international problem.
Many books have pages of thread data some are good and some are bad.
If a manufacturer doesn t have the original document, an ANSI standard for example, they run the risk of having problems pop up along the way, and these problems never show themselves until the machines spit out a couple hundred thousand parts, said Cox. One way to avoid this aggravation is to buy the specification sheet. Cox said, Avoid using someone s interpretation and get the document. They re written in plain English and are very easy to understand. Customer-provided drawings with thread specifications that make no real reference to the standards leave everyone second guessing all the way down the line, including the people supplying the gages and cutting tools for the job, said Cox.