Circular Dies & Hexagon Die Nuts

Circular dies cut external threads on bar, rod, and studs — by hand in a diestock, in a lathe tailstock, or in a die head on a production machine. They’re a low-setup threading method that suits one-offs, repairs, and thread chasing on smaller diameters where a thread mill or single-point tool would be overkill.

We stock circular dies in high-speed steel covering metric coarse and fine threads, BSP, BSW, and UNC/UNF forms, plus hexagon die nuts for rethreading and cleaning up existing external threads. Matching diestocks are available in the correct sizes for the common die diameters.

All held in UK stock. Order before 4.30pm and it ships same day.

Circular dies vs. hexagon die nuts

A circular die in a diestock cuts a full external thread from scratch — you can adjust the die split for a trial pass then close it to full depth for the finished thread. A hexagon die nut is a compact six-sided version used primarily for rethreading: running over a damaged or corroded external thread to restore the profile. For threading new bar, use a circular die. For chasing an existing thread, a die nut is faster and needs less clearance around the workpiece.