Here in the Goodson Tech Department we get a lot of questions about which brake lathe cutting tip to use and why. We tested our most popular brake lathe cutting tips - RT-A and RT-312 to get some concrete answers for you.
Tests were conducted by the same operator on an Ammco 4000 Brake Lathe. The rotor being turned was mounted using a Quick Chuck Mounting Adaptor equipped with a CE-8 Rubber Silencer Band.
The titanium coating is applied to a carbide substrate. It is specifically developed for cutting, turning and boring most materials at a moderate to low speed. Its unique mechanical and thermal properties make it ideal for cutting drums and rotors while providing longer life and more cuts per tip.
Standard v. Honed Edge v. Titanium Coated v. Standard Round v. Titanium Coated Round
|Standard Triangle||Honed Edge Triangle||Titanium Coated Triangle||Standard Round||Titanium Coated Round|
Single Pass Cut: .006" off each side
|Single Pass Cut: .010" off each side
Rotor Diameter: 11"
Machine Speed: Medium
Fast Cut: .006" off each side; Slow Cut: .002" off each side
NOTE: An Ra finish of 14 to 70 off the production line is recommended. The lower the Ra number, the better the finish.
Triangular Cutting Tips v. Round Cutting Tips
Single Pass Cut: .006" off each side of rotor
Rotor Diameter: 11"
Machine Speed: Fast
Each test is another pass with the same cutting tip. For example, Test D represents four (4) passes with the same tip.
Standard Carbide Tips
|Triangle : RT-A||Round : RT-312|
|Test A (1 pass)||Temp: 136º | Ra: 133||Temp: 110º | Ra: 73|
|Test B (2 passes)||Temp: 138º | Ra: 136||Temp: 109º | Ra: 74|
|Test C (3 passes)||Temp: 138º | Ra: 138||Temp: 110º | Ra: 76|
|Test D (4 passes)||Temp: 136º | Ra: 140||Temp: 109º | Ra: 77|
|Test E (5 passes)||Temp: 139º | Ra: 143||Temp: 109º | Ra: 78|
Titanium Coated Carbide Tips
|Triangle : RT-A-T||Round : RT-312T|
|Test A (1 pass)||Temp: 103º | Ra: 101||Temp: 94º | Ra: 77|
|Test B (2 passes)||Temp: 103º | Ra: 101||Temp: 94º | Ra: 65|
|Test C (3 passes)||Temp: 121º | Ra: 101||Temp: 96º | Ra: 68|
|Test D (4 passes)||Temp: 128º | Ra: 127||Temp: 104º | Ra: 71|
|Test E (5 passes)||Temp: 136º | Ra: 132||Temp: 110º | Ra: 74|
As always, if you have any questions about this or any other technical topic, contact the Goodson Tech Service Department by phone (1-800-533-8010) or email