Parting, Grooving & Cut-Off

Parting, Grooving and Cut-Off Tooling

Parting and grooving tools cut narrow, deep slots into rotating workpieces on a lathe — parting (sometimes called cut-off) separates a finished part from the bar stock it was machined from; grooving cuts retaining ring grooves, O-ring seats, and decorative profiles. The tooling is specialised because the cut is narrow, the side clearance is critical, and the tool tip is unsupported by the surrounding material. AIMS Industrial stocks parting, grooving, and cut-off tooling for lathe and turning workshops.

What's in the range

• Parting blades and holders — HSS blade in a holder, the traditional parting setup for general lathe work
• Indexable parting tools — replaceable carbide insert in a steel holder, longer life and faster cutting than HSS
• Grooving tools — for cutting external and internal grooves of specific widths and depths
• Cut-off inserts — replacement carbide inserts for indexable parting tools
• Internal grooving bars — for cutting grooves inside bores
• Threading tools and tips — closely related tooling, often sharing holder geometry

HSS blade versus indexable

HSS parting blades are the traditional choice — economical, easy to resharpen, and forgiving of speed and feed errors. Indexable carbide tooling cuts faster, lasts longer between insert changes, and produces better surface finish — but is less forgiving of vibration, deflection, and interrupted cuts. For occasional parting work in mixed materials, HSS earns its place; for production parting at speed, indexable is the right call.

Common parting problems

• Chatter — usually the tool projecting too far from the holder, or workpiece overhang causing flexure. Reduce projection and check setup.
• Tool dig-in — cutting edge below centre height grabs as the cut deepens. Set the tool tip exactly on centre.
• Poor surface finish — feed rate too high, or tool nose not properly ground. Reduce feed rate first; check tool geometry second.
• Tool breakage — usually misalignment, oversized feed, or trying to part too large a workpiece for the holder. Match tooling to job size.

Insert geometry — what to look for

Parting and cut-off inserts come in different widths and chip-breaker geometries. Wider inserts are stiffer and tolerate higher feed rates; narrower inserts waste less material but require more rigid setups. Chip-breaker geometry on the insert top face controls how the chip curls — important on continuous cuts to prevent a long ribbon wrapping around the workpiece.

Brands stocked at AIMS

SECO is the approved premium brand for indexable parting and grooving tooling. We also stock HSS parting blades and holders from quality manufacturers in the standard width and length range. Inserts and replacement blades are stocked alongside the tooling to support production work.

Setup advice

Tool tip exactly on workpiece centre height (a fraction high or low changes the rake angle dramatically and causes problems). Tool projection from the holder should be the minimum needed to clear the workpiece — every extra millimetre of projection increases flexure. Workpiece projection from the chuck should also be minimal; long overhangs flex and cause poor finish or chatter.

Need help matching tooling to a specific lathe, workpiece, or material? contact our team — we'll work through the spec.