Dormer circular split dies can be used by hand or machine. Because the die has a split it can be adjusted slightly to provide a thread slightly smaller or larger than the norm.
UNC Adjustable Dies
Application: For Production of components less than three times diameter in length.
Tolerance : 2A Adjustable
Chamfer Lead : Two Threads
Surface treatment : Bright
Material : HSS - High Speed Steel
BS1127:1950