ER Collets

  • Standard ER Collets conforming to DIN 6499.
  • Manufactured from high quality spring steel.
  • Used for rapid and secure mounting of cylindrical shanked tools.
  • Available types:
    • DIN 6499
    • Tap Collets
    • High Precision Collets
    • Sealed Collets: for Through spindle coolant chanelling
ER Collets

Spring Steel

DIN 6499


What is a collet?

Collets are clamping units used for holding cylindrical tool shanks. They are manufactured from spring steel and are capable of retaining their form after the compressive forces are removed. The collets come in a number of sizes, each being able to hold a specific shank diametre within 0.5mm or 1mm of range. The collets are mounted onto the collet chuck by means of the nut. As the nut is tightened, the collet compresses into the tool shank forming a tight grip over it.

Mounting and dismounting the collet

Insert the collet into the nut at an angle until the collet's face surpasses the extractor ring. The collet compresses to move past the ring and then retains back it's original form once the ring grips around its groove. If done correctly the collet's face should be nearly flush with that of the nut. 

Mount the assembly onto the collet chuck by rotating the threads of the nut onto that of the adaptor. Clamp the cutting tool inside the collet's bore and proceed to further tighten the nut onto the chuck by means of a wrench. Do not screw the nut onto the chuck bearing a collet, this can not only break the nut but damage the collet as well.

Similarly to remove the collet from the nut, first dismount the assembly from the chuck and the cutting tool from the collet. Push on one of the collet fingers until it lets loose of the extractor ring causing the collet to tilt at an angle. Continue pushing the collet off the nut. TYPE BORE SIZE/RANGE  Action
C-ER8 ER-8 1-5mm (0.5mm step)
C-ER11 ER-11 1-7mm (0.5mm step)
C-ER16 ER-16 1-10mm (1mm step)
C-ER20 ER-20 2-13mm (1mm step)
C-ER25 ER-25 2-16mm (1mm step)
C-ER32 ER-32 3-20mm (1mm step)
C-ER40 ER-40 3-26mm (1mm step)
C-ER50 ER-50 10-34mm (2mm step)
C-TAP ER-16-50 ⌀3.5-32mm ▢ 2.7-24mm
Also available in High Precision and Sealed variants