How to find the right Concave Radius Milling Cutters AI guide
Written by an AI model from its trained knowledge.
What the AI looks for in Concave Radius Milling Cutters
- Radius size
- Match the cutter's nominal radius to the convex edge radius you need on the part. A concave cutter forms a rounded (convex) edge. These are form cutters, so the radius is fixed and cannot be adjusted in setup.
- Arbor bore
- The bore must equal your arbor diameter exactly, typically 1 in or 1-1/4 in for inch arbors and 22, 27 or 32 mm for metric, with a matching keyway. A mismatched bore or a missing keyway causes runout and slippage on the arbor.
- Form-relieved teeth
- Choose form-relieved (cam-relieved) teeth, which are resharpened only on the tooth face. Grinding only the face keeps the radius profile accurate over the cutter's life.
- Material
- Cobalt HSS (M42 or M35) for steels and tougher alloys; plain M2 HSS for aluminum, brass and mild steel. Cobalt keeps its hardness at the heat a full-radius form cut produces.
- Full vs quarter radius
- Use a full half-circle profile to round a whole edge or rod end, and a corner-rounding (quarter) profile for single edges. Buying the wrong profile leaves a step or flat on the part.
Brands that matter
- KEO: Broad US catalog of HSS arbor-type form cutters, including radius profiles.
- Somta: South African maker with a wide range of HSS arbor cutters.
- HHIP: Budget import tooling, suitable for hobby and occasional use.
- Niagara Cutter: US maker of HSS milling cutters.
What to avoid
- Unbranded cutters that do not state the radius tolerance or the bore size.
- Running form cutters at slab-cutter feeds. Wide contact causes chatter, so reduce feed and speed.
- Regrinding the relief or flank of a form-relieved cutter, which destroys the profile.
Questions
Concave or convex: which one rounds an edge?
A concave cutter has a hollow profile and produces a rounded, convex edge on the work. A convex cutter cuts a concave groove.