Round Carbide Insert Bits, 10-Pack | Fits AMMCO Brake Lathes | Part #40610

Brake Lathe Details

Replacement round carbide insert bits for AMMCO bench brake lathes equipped with round-style tool holders. The circular cutting edge maintains consistent geometry as it rotates in the holder, allowing the operator to index a fresh cutting edge once one section dulls. This extends the working life of each insert across more rotor cuts than fixed-edge inserts before replacement is needed.

Part #: 40610
Quantity: 10 inserts per pack
Cutter type: Round (indexable)
Material: Industrial-grade carbide
Application: Rotor and drum resurfacing on AMMCO brake lathes with round-bit holders
Lathe compatibility: AMMCO bench brake lathes with round insert holders (such as 40608, 40609, 40600)
Function: Indexable round-edge cutter for extended working life per insert

Browse more Brake Lathe Parts, Silencers & Chucks.

Frequently Asked Questions (FAQs)

How many cutting edges do I get with a round insert?

Unlike triangular bits which have 3 or 6 fixed points, round inserts offer "infinite" indexing. You can rotate the bit as little or as much as needed to find a sharp edge. Most technicians find they get 4 to 6 times the usable life out of a single round bit compared to a standard triangular bit.

Are these bits better for rotors or drums?

They are excellent for both, but they truly excel in drum resurfacing and heavy rotor roughing. The rounded edge is much more durable when hitting the "hard spots" or "rust scale" found on older drums. For a final mirror finish on a high-carbon rotor, they are just as effective as positive rake bits when used with a slow feed rate.

Will these fit my standard Ammco tool holder?

These bits require a Round Bit Tool Holder (typically the #01 and #02 holders used in Ammco 40608/40609 sets). They will not fit into the triangular pockets of standard negative or positive rake holders.

Why should I switch to round bits from triangular bits?

The main reason is cost-per-cut. Because you can use the entire circumference of the bit, you throw away less carbide. Additionally, the rounded cutting edge is less prone to "chipping" if the lathe experiences chatter or if the bit hits a particularly hard section of the rotor.

What is the best way to index a round bit?

Loosen the mounting screw just enough to allow the bit to turn. Use a small scribe or your finger (if wearing gloves) to rotate the bit a few degrees. Always clean the seat with a brush or compressed air before re-tightening to ensure the bit sits perfectly flat for the next cut.