Machining a thread by cutting chips out of the groove rather than forming it. Cutting suits large diameters, short runs, hard or brittle materials and most tapped holes. The cut severs the grain at the root and leaves tool marks, so cut external threads have lower fatigue strength than rolled ones in the same material.
Heard on the job
Six pieces? Cut the threads on the lathe, it's not worth buying rolling dies for two-inch studs.
Also heard as
- cut thread
Do not mix it up with
- Thread rolling: Thread rolling forms the thread by displacing metal, giving better fatigue strength and no chips.
Related terms
Thread rolling
Forming threads by squeezing a blank between hardened dies, displacing metal instead of cutting it away.
Percent thread
How deep an internal thread is compared with full theoretical depth, set mainly by the tap drill size.
Fatigue
Cracking that grows a little with every load cycle until a bolt breaks far below its static strength.