SCT Threading Die Set


Threading dies are the heart of a spoke machine. Beginning in 2021 we now offer three distinct die sets, each designed exactly for one of the three gauge pair options—14/15G, 13/14G, or 12/13G. You can reshim any of these to run the other gauges (as before) but using them for their designed pair is smoother and more stable. Never before has a manual spoke machine made this specialty offering. It's part of our long term quest for perfection in threading. If your machine was set up with a single die set (to do all 3 gauge pairs) then you are using the 14/15G set. Now you can replace that or change to a design closer to your everyday use. Each set comes with a selection of 12 shims, six thicknesses for each die—0.1, 0.2, 0.3, 0.4, 0.5, and 1.0mm.

From 2018 into 2020 we offered a double sided design from TW but after delivering nearly 100 sets we changed to a new source—a small, experienced, perfectionist maker in Japan. The newest dies are single sided and to a higher standard of finish. Double sided (the previous design) offer potentially longer service but tooling on both dies sides introduces variations that interfere with thread shape at the microscopic level. Our new dies are not cheaper but dialing them in is smoother. Threading action is also excellent as these have full form finish relief, meaning the fixed die entry ramps are fully tooled, a feature our previous die maker was unable to do.

A die set is worn when its surface feels rough. Close examination shows material has fractured and broken away. The metal does not wear down smoothly—instead, it fatigues and crumbles. Even when wear is advanced, good threads can be made since the spoke rotates six times  in the process so the die has many chances to form a correct thread. Adjusting your machine to have moderate thread depth will help dies last longer. Rather than going to ISO/JIS spec (2.27mm thread OD on 14G) stay a bit below this (2.20mm). Oversized spokes (2.0+ wire diameter) come around and we don't want your machine to be under excess pressure. That will wear dies. Always best to use oil when threading and brush out the dies after a few runs. Any oil will do and rag or brush is effective. Use stuff that’s sustainable and smells good. Adjust the shimming of the dies as explained on page 8 of the Operation Manual, available to download here.  

Collections: Threading