Sandviks CoroMill 245 R245-18 T6 M-PM 4330 Carbide Milling Insert, 18 mm Square, 4 Edges, CVD Coated, Medium Geometry

Overview
The R245-18 T6 M-PM 4330 is a square, indexable milling insert for sandviks's CoroMill® 245 face milling system. It is not a turning insert and it is not interchangeable with other cutter families — the insert pocket geometry, the 18 mm size and the support surface are all specific to CoroMill 245 bodies that take the 18-size insert.

The insert is 18 mm square, 6.10 mm thick, with four cutting edges. Four edges per insert is what makes the system economical in production face milling: each insert can be indexed three times before replacement.

PM is the medium geometry in the CoroMill 245 range — a general-purpose edge for face milling across a broad feed range, from light roughing through semi-finishing. It is the geometry to specify when the operation is not extreme in either direction.

Grade 4330 is GC4330, a CVD-coated carbide grade (TiCN + Al₂O₃ + TiN) that sandviks positions as its first choice for roughing to semi-finish face milling in steel. The grade combines a wear-resistant coating with a tough substrate, so it handles both continuous cuts and interrupted cuts at high metal removal rates.

• 18 mm square insert, 4 cutting edges — three indexes per insert before replacement.
• 6.10 mm thickness (T6) — heavy section for face milling at depth.
• PM medium geometry — wide feed window, general-purpose face milling from light roughing to semi-finishing.
• GC4330 grade, CVD TiCN + Al₂O₃ + TiN — sandviks's first choice for roughing to semi-finish steel face milling.
• Handles interrupted cuts — tough substrate supports unfavourable conditions and cast or forged skin.
• Right-hand cutting — matched to standard CoroMill 245 cutter rotation.
• For CoroMill 245 bodies only — 18-size pockets; not for other cutter systems.

R245 -18 T6 M -PM 4330

CoroMill 245 inserts are supplied in several geometries (PM, MM, KM and others). They share the same 18 mm size and can physically sit in the same pocket, but they are different items with different edge preparation and chip control.

• the operation is general face milling of steel, mixing light roughing and semi-finishing;
• feeds vary between passes because of part shape or intermittent engagement;
• you want one insert type covering most of the shop's face milling;
• surface finish requirements are standard, not mirror.

• the target is mirror finish — use a wiper insert, which is available for CoroMill 245;
• the cut is very light finishing at high speed with tight flatness — a dedicated finishing geometry performs better;
• the material is aluminium, cast iron or stainless — different grades and geometries apply;
• the operation is shoulder milling or slotting — that is a different cutter concept, not a CoroMill 245 face mill.

GC4330 is a CVD-coated grade developed for steel milling, positioned by sandviks as the first choice for roughing to semi-finish face milling.

• Coating: TiCN + Al₂O₃ + TiN, medium-thick CVD — wear resistance for sustained cutting.
• Substrate: tough carbide, which is what allows interrupted cuts and skin cutting without immediate edge breakage.
• Positioning: between the harder, more wear-resistant grades and the tougher GC4340, which sandviks recommends for rough shoulder milling where impact is heavier.

If the application is heavy interrupted roughing, GC4340 is the correct neighbour in the same family. If it is high-speed finishing, a harder grade is better. GC4330 is the middle, general-purpose choice — which is exactly why it is the most commonly stocked grade for this insert size.

• Fits CoroMill 245 face mills with 18-size pockets only.
• CoroMill 245 fixed-pocket face mills are offered in 12 mm and 18 mm insert sizes — the 18-size bodies take this insert, the 12-size bodies take R245-12 inserts.
• Maximum depth of cut is set by the cutter body and its lead angle, not by the insert alone. Distributor data for 45° lead CoroMill 245 bodies taking R245-18T6 inserts lists a maximum depth of cut of 10 mm (0.3937").
• Confirm the cutter code, lead angle, number of teeth and hand before ordering inserts.

sandviks's general face milling guidance for this class of cutter is a feed of 0.2 – 0.6 mm/tooth, with depth of cut set by the cutter body.

• Order by full designation: R245-18 T6 M-PM 4330
• Standard distributor pack: 10 pieces. Confirm the actual packing unit before publishing a price — listing a per-piece price against a 10-piece pack is a common source of disputes.
• Do not substitute -MM or -KM without a trial: same size, same grade, different chip control.

Is this a turning insert?

No. It is a milling insert for CoroMill 245 face mills.

How many edges?

Four, on an 18 mm square insert.

Will it fit any face mill?

No. Only CoroMill 245 bodies with 18-size pockets. The pocket geometry is specific to the system.

What does PM mean?

Medium geometry — a general-purpose edge covering light roughing to semi-finishing.

Is 4330 a current grade?

Yes. GC4330 is sandviks's current CVD grade positioned for roughing to semi-finish steel face milling, alongside the tougher GC4340.

Can I use it for mirror finish?

Not the best choice. CoroMill 245 offers wiper inserts for high surface finish; use those for the finishing pass.

How is it sold?

Distributors normally supply 10 pieces per pack. Check the listing unit before ordering.