Tungsten alloy tap and die set Metric & SAE. Covers most common sizes in both ranges including a suprisingly high 3/4" in the AF series. These taps and dies are well suited to thread chasing for restoring threads and whilst they will cut threads as well, will not last as long as High speed steel or Chrome Alloy made products under those conditions. As the thread restorer and occasional thread maker, these taps and dies are are excellent choice for workshop and self repairer alike at a price that is hard to beat.