® Thread Turning Technical Section Important Points about Carmex Threading Inserts 1. In most thread forms internal and external threads have differentdepth and radii, thustools are notinterchangeable4. Profiles of Carmexinternal & externalthreading insertsare precision ground to ensure accurate thread geometry when used in their 2. The Insert reliefangle of a standardCarmex externaltoolholder is 10˚; for aninternal toolholder it is 15˚.This 5º difference iscorrespondingtoolholders.Using internal insertswith an external holderwill result in distortion of angleand insert geometry. to provide additional necessary radial clearance. 5. Insert and toolholder 3. Our built-in relief angles should always match. ensure automatic insert An IN-RH insert must be flank angle clearance. used with an IN-RH toolholder. No mismatch is allowed. Flank Clearance Angle A04-6