Big Kaiser has launched the HMCJ, a milling chuck with peripheral coolant supply, designed to support heavy-duty and finish end milling tasks using Ø1/2” or Ø12mm cutters.

This member of the Hi-Power Milling Chuck (HMC) family features a clamping bore with fine slots surrounded by hundreds of needle bearings, which the company says are intended to ensure concentric, precise, and smooth clamping when the nut is tightened. The company says the HMCJ applies the highest gripping force to the cutting tool shank of any comparable milling chuck in its class, and five to six times greater compared to collet chucks.

Slimness is a feature of the HMJC.The design of this new chuck brings the nut diameter down to 1.260” (32mm), claimed to be the smallest in its class. This was achieved while maintaining a cross section of .394” (10mm) to prevent chatter and deliver cutting security. The max jet-through coolant pressure is 70 bar.

Despite being designed for heavy cutting, the HMCJ milling chuck is able to maintain a runout accuracy of 10 microns at 4xD, giving it additional flexibility for use on finishing applications. For additional rigidity and accuracy, the CAT and BT interfaces are BIG-PLUS as standard, however, a BIG-PLUS spindle is not necessary. A Ø32mm straight shank design is also available.

It is also possible to use smaller diameter milling tools through the use of PJC Reduction Collets. The Ø.500” HMCJ can then accept Ø3/8” and Ø1/4” shanks, and the Ø12mm HMCJ can accept Ø10mm, Ø8mm and Ø6mm shanks.