Thread cutters for wood come in pairs and include a tool for exterior threads and one for cutting matching interior threads. These thread cutters are perfectly designed for making screw tight lids on boxes and caskets. This fascinating and practical aspect of woodturning includes a range of cutting tools that have been produced from High Speed Steel in 10, 16 and 20 threads per inch (TPI). They have been designed with a unique, enhanced helix angle specially designed for use in wood. This 3 piece thread cutting sets consist of a pair of thread cutters (one for internal cuts and one for cutting matching external threads), a thread and sizing gauge (which takes out the guess work out of dimensioning) and the Focus on Specialist Woodturning Tools Part 3 DVD.