Techniks 04220-04 ER20 Collet 4mm Through Coolant

Product Description

The TECHNIKS 04220-04 is an ER20 series collet designed for precision tool holding in CNC machining centers, milling machines, and high-speed spindle applications. Built to a 4mm collet size with a Total Indicator Runout (TIR) of 0.0002 inches (0.0050 mm), this collet delivers the concentricity required for tight-tolerance work. Through-coolant capability allows cutting fluid to pass directly through the collet body to the tool tip, supporting effective chip evacuation and tool life in demanding cutting operations. Installation is handled by machinists and CNC service technicians in production and job-shop environments.

This collet is suited for use in ER20-compatible collet chucks found in vertical and horizontal machining centers, CNC lathes with live tooling, and high-speed routing spindles. The 4mm bore size accommodates tooling with a 4mm shank. Through-coolant design makes it well suited for drilling and reaming operations where directed coolant flow at the cutting edge improves performance and extends tool life in ferrous and non-ferrous materials.

Key Features

• ER20 collet series for use with standard ER20 collet chucks and nuts
• 4mm collet bore size for 4mm shank tooling
• TIR of 0.0002 inches (0.0050 mm) for high-precision, low-runout tool holding
• Through-coolant design directs cutting fluid to the tool tip during operation
• Compact form factor compatible with high-speed spindle applications

Compatibility

Designed as a direct-fit replacement or spare for ER20-compatible collet chucks accepting 4mm bore collets with through-coolant capability.

Installation Notes

Installation and replacement should be performed by a qualified machinist or CNC service technician with the spindle fully stopped and machine power isolated. Use a proper ER20 collet nut and spanner wrench to seat and torque the collet correctly - do not use improvised tools. Inspect the collet bore and chuck taper for chips or debris before seating. Verify TIR with a test indicator after installation when operating at high spindle speeds or holding tight-tolerance tooling.