These British manufactured High Speed Steel Ground Threading Die Nuts have a machined lead-in for ease of use and accurate thread cutting. A Die Nut does not require a 'Die-Holder' and is normally used "free-hand" with a spanner. Die Nut's are normally used for thread cleaning/restoring and not for producing a 'new threads'.
B.S.W. (Whitworth) H.S.S. Die Nuts (3/4" - 2")