Thereby hangs a thread

1 min read

A range of thread repair kits, tools and threaded inserts is available from WDS Component Parts, the Leeds-based engineering components company.

These kits and inserts are used to repair worn or broken threads on any type of equipment, from a machine tool to a vehicle’s engine.

Stripping the thread of a tapped hole is not an uncommon occurrence in most fields of technical activity. This may happen because of excessive loads, misalignment when screwing two parts together or the mismatching of threads. Similarly, worn threads are found on many older machines or on machines that are subject to heavy usage patterns.

Unfortunately, a damaged thread can have consequences far beyond its own boundaries. In worse-case scenarios, it could mean a complete machine is rendered inoperable, which could, in turn, halt operations on a production line or bring mobile plant to a standstill, generating significant knock-on costs, in terms of lost revenue or project delays. Thus, the need to be able to repair threaded hole quickly, simply and effectively is paramount.

The inserts available from WDS are screwed into position to replace threads that have been damaged. To install them, the user has to drill out the damaged thread, but this has the knock-on effect of enlarging the diameter of the hole. So, then the hole has to be retapped with a tapping tool, typically provided as part of a WDS kit. With the damaged threaded hole prepared, the threaded insert can be screwed into place, using an inserting tool from the kit. After the repair, the hole is reformed to a specified diameter and thread.

Because the range of possible uses is almost infinitely varied, WDS offers different sizes and types of thread repair inserts, wire inserts in which coiled wire is tightly wound to replicate a tapped thread, and heavy-duty thread inserts made from carbon steel or 303 stainless steel. Further, standard and thin-walled options are also available.

"Recognising the importance of these humble inserts, WDS recently extended the range, so that a greater number of repairs requirements can be addressed," said the company. “The heavy-duty inserts now come in a range of sizes from M5 to M12 and can be used to rethread holes from 6.9mm to 20.5mm diameter. The length of the inserts is from 8mm to 16mm.”

Typically, the inserts weigh a few grams each and are supplied in packs of 10 or in kits that include the necessary tools for drilling out the damaged thread, retapping the whole and fitting the insert.