Kemmler SK Weldon End Mill Holders with Coolant Channels

Available Sizes and Part Numbers

Purpose and Application

Weldon Kemmler toolholders with coolant channels are engineered for CNC milling machines and machining centers equipped with SK spindles according to ISO 7388-1 (formerly DIN 69871). They are designed for reliable clamping of end mills and drills featuring a cylindrical Weldon shank (DIN 1835 Form B). Integrated internal coolant supply channels solve chip evacuation problems and provide optimal cutting edge cooling during deep cavity milling, shoulder machining, and difficult-to-machine steel processing.

Design and Features

Tool clamping is performed via a clamping screw that prevents shank movement or slippage under load. Longitudinal coolant channels are machined along the clamping bore: holders for diameters 6 to 18 mm feature 2 channels, while diameters 20 to 40 mm feature 4 channels. Starting from a clamping diameter of 25 mm, holders are equipped with two clamping screws. An O-Ring seal is included for tools with internal coolant supply. Bore radial runout is ≤ 3 µm, bore tolerance is H4, and fine balancing complies with G 2.5 at 25,000 rpm. An integrated RFID chip slot is provided as standard.

Compatibility

Compatible with machine spindles featuring SK 40 and SK 50 tapers (ISO 7388-1 / DIN 69871). Designed for clamping cutting tools with DIN 1835 Form B shanks. Pull studs compliant with ISO 7388-3 (formerly DIN 69872) are used for spindle mounting.

Selection Parameters

Toolholder selection depends on the spindle taper SK (40, 50) and clamping diameter DCONWS (6, 8, 10, 12, 14, 16, 18, 20, 25, 32, 40 mm). Available gage length LPR options range from 50 mm to 160 mm.

Key Advantages:

• Forced Edge Cooling: 2 or 4 coolant channels direct fluid straight into the cutting zone to extend tool life.
• Anti-Slippage & Pull-Out Protection: The clamping screw perpendicularly locks the Weldon shank flat.
• Sealing & Complete Set: Supplied complete with clamping screw and O-Ring seal for tools with through-coolant.
• Precision Accuracy: Bore tolerance H4 and radial runout ≤ 3 µm.
• High-Speed Balancing: Fine-balanced to G 2.5 at 25,000 rpm to reduce spindle vibration loads.