Lathe Tool Bits

Lathe Tool Bits

Lathe tool bits — also called toolbit blanks — are unground cutting tool blanks that the machinist grinds to the required profile for turning, boring, facing, threading and parting operations. They are the foundation of traditional lathe tooling, used in conjunction with a bench grinder and standard tool post.

Sutton Tools, Bordo and Maxigear

AIMS stocks lathe tool bits from Sutton Tools, Bordo and Maxigear. Sutton's M301 series covers standard HSS (high speed steel) square tool bits in a full range of sizes from small precision work up to heavy-duty turning. The M302 cobalt steel series adds 5% cobalt for improved hardness and heat resistance, extending tool life when turning harder materials. Round tool bits (M300 series) are ground for boring bars and special holder applications.

Parting Off Tool Bits

Bordo's HSS cobalt parting-off bevel toolbits are a workshop staple — precision ground with a bevel clearance to reduce drag and heat during cutoff operations. Parting tool bits require careful grinding and setup but are cost-effective for cutoff work on a capstan or centre lathe.

HSS vs Cobalt Steel

Standard M2 HSS is the workhorse grade for general turning of mild steel, aluminium, brass and plastics. M35 cobalt steel (5% cobalt) is harder and retains its edge better at elevated cutting temperatures — the right choice for stainless steel, hardened steels, titanium and other difficult materials. Both grades can be hand-ground to any profile required using a standard bench grinder and dressing wheel.

Square and Round Blanks

Square blanks are the most common form and suit the majority of standard tool post holders. Round blanks are used in boring bars, fly cutters and special-purpose holders. AIMS stocks a range of sizes across both forms — match the blank size to your tool post's holder opening to ensure rigidity and correct cutting height. For production turning where insert indexing is preferred over regrinding, see our SECO indexable inserts.