Weldon tool holders are rigid clamping systems widely used on CNC machining centres for roughing and heavy drilling operations that demand high metal removal rates.
Watch Temak Teknik’s video below on the design, advantages and on-machine application of Weldon tool holders:
Key Features and Advantages
- Prevents Axial Slippage (Pull-In): In Weldon holders, the clamping screw (set screw) seats directly on the flat on the cutting tool shank (Weldon shank / D-shank) [00:14]. This mechanical lock completely prevents the tool from slipping into or pulling out of the holder under high axial loads [00:59].
- Power for Heavy Cuts and Roughing: Delivers high torque transmission in heavy drilling with U-drills (indexable insert drills) and in rough end milling [00:50].
- Mechanical Security: Compared with collet chucks, it provides a positive lock on the shank flat in addition to friction, so the tool does not spin under high cutting forces [00:50].
Selection and Application Considerations
- Weldon Shank Compatibility: Use only with cutting tools that have a Weldon flat on the shank [00:14]. With plain/cylindrical shank tools, the screw applies point pressure, causing runout and unstable tool behaviour [02:06].
- Diameter Standards: Unlike collet chucks, they do not cover a wide clamping range; a separate Weldon holder of exact size is required for each shank diameter (e.g. 6, 8, 10, 12, 16, 20 mm) [00:31].
- Runout Factor: Because the screw presses the tool from one side, they do not offer runout as low as hydraulic or shrink-fit chucks in precision finishing; their main purpose is roughing and rigidity.