Fasteners with imperial threads

Many American companies manufacture their products at European locations and require fasteners with imperial threads. Many American products that are linked with these screws are also exported from the US. For this reason, it is important to us to offer fasteners with imperial threads in addition to fasteners with metric threads. Firstly, we would like to present two types of threads in more detail.

First of all, the standard American coarse thread UNC and the standard fine thread UNF. These two types of threads are listed as standard in the new range of Würth Industrie Service items. The difference between the metric and American threads is that the thread pitch (e.g. M8 x 1.25 mm) is specified in metric and the number of threads in the American thread is specified over one inch (25.4 mm).*

Inch Fasteners

It is not only the thread types that are different between metric and imperial. Imperial items can be found in the US and the UK. There are also differences here. The flank angles in an American and English standard thread differ as follows:

Difference between the flank angles of UNC (US) and BSW (UK)

  • UNC = American standard coarse thread, 60º flange angle
  • BSW = British standard coarse thread, 55º flange angle

* 1 inch = 25.4 mm

​ ​