CNC Threading Inserts are precision carbide cutting inserts designed for external and internal thread machining on CNC lathes. Available in ISO metric, UN, NPT, Whitworth and other thread profiles, our threading inserts provide stable cutting performance, accurate thread profiles and reliable tool life for steel, stainless steel, cast iron and other engineering materials.
CNC threading inserts are replaceable carbide cutting inserts used on CNC lathes to machine threads on metal parts.
Instead of grinding a thread directly with a solid tool, the insert is mounted in a threading tool holder, and the CNC machine moves it along the workpiece according to the programmed thread profile.
For example, when producing an M20 × 1.5 external thread, the CNC machine controls the spindle speed and feed so the insert cuts the correct 1.5 mm thread pitch over multiple passes.
Main types of CNC threading inserts Type Application Example External threading inserts Cutting threads on the outside diameter 16ER, 22ER Internal threading inserts Cutting threads inside a hole 16IR, 22IR Full-profile inserts Produces the complete thread profile and crest ISO Metric Partial-profile inserts Can machine different pitches within a range General-purpose Multi-tooth inserts Multiple thread teeth for high productivity High-volume production What does 16ER / 16IR mean?
This is particularly important when selling threading inserts.
16ER = external threading insert 16IR = internal threading insert 16 = insert size E = external I = internal R = right-hand cutting direction
For example:
16ER AG60 → external, right-hand threading insert with a 60° profile.
16IR AG60 → internal, right-hand threading insert with a 60° profile.
Common thread standards
CNC threading inserts are available for different thread standards:
ISO Metric threads — M UN / Unified threads — UNC, UNF, UNEF NPT threads — National Pipe Thread BSP / Whitworth threads Trapezoidal threads ACME threads Partial-profile and full-profile threads Why carbide inserts are used
CNC threading inserts are usually made from cemented carbide, often with coatings such as TiN, TiCN, TiAlN or AlTiN.
They provide:
High wear resistance Stable thread accuracy High cutting speed Longer tool life Consistent performance in CNC production Easy insert replacement
