Laydown Threading Shim Selection Guidelines It is essential to select the correct shim to ensure thread quality and maximum tool life These paramet

Laydown Threading Shim Selection Guidelines It is essential to select the correct shim to ensure thread quality and maximum tool life. These parameters are needed Pitch Pitch diameter Number of starts Feed direction NOTE When considering method of thread cutting, the part’s shape and stability and the flow of chips are determining factors in your decision. Laydown Selection Chart pitch (mm) del ar h P -B .2 "o ae P 10 9 8 7 6 5 4 3 2 1 0 1 2 3 4 5 6 7 8 9 10 RH thread/RH tooling LH thread/LH tooling LH thread/RH tooling RH thread/LH tooling pitch (mm) NOTE For multi-start threads, use the lead value instead of the pitch. Diagram of Thread Lead Angles To calculate the lead angle of a given thread, use this formula B Arctan P S re Dq B thread lead angle De effective pitch diameter of thread wear P 1/TPI TPI threads per inch S number of starts single-start, lead pitch multiple-start, lead pitch (x) number of starts All toolholders are designed with an inclination angle 1.5°. When turning standard threads with a lead angle of 1-2°, this guarantees adequate clearance at the flanks of the insert’s thread tooth. The thread lead angle and the required inclination angle of the insert are given by B. Cutting edge height is constant at every shim and insert combination. All toolholders are supplied with 1-1/2° lead angle. F100 Technical Information Laydown Threading Widia