Kennametal 1729939 ER40 Collet 0.75 Inches

Product Description

The KENNAMETAL 1729939 is an ER40 series collet designed for use in CNC machining centers, milling machines, and other rotating spindle applications that accept ER40 toolholders. This collet holds workpieces or cutting tools with a nominal clamping capacity of 0.75 inches and delivers a total indicator runout (TIR) of 0.0203 mm, supporting tight tolerances in precision machining operations. With an overall length of 1.811 inches and a 41 mm outer diameter, it fits standard ER40 collet chucks and is installed by machinists and toolroom technicians in production and job-shop environments.

This collet is suited for use in both production and toolroom settings where consistent clamping force and low runout are required. Typical applications include end mill and drill chuck retention in vertical and horizontal machining centers. The ER40 series is a widely adopted standard in metalworking, making this collet applicable across a broad range of compatible toolholding systems. Minimum collet capacity is 0.71 inches, giving the collet a working clamping range appropriate for standard shank tooling near the 3/4-inch size.

Key Features

• ER40 series collet with 0.75-inch nominal clamping size
• Low TIR of 0.0203 mm for precision tool runout control
• Overall length of 1.811 inches fits standard ER40 chuck bodies
• Minimum collet capacity of 0.71 inches provides a defined clamping range
• 41 mm outer diameter conforms to ER40 collet geometry standards

Compatibility

Designed as a standard ER40 series replacement collet compatible with ER40 collet chucks and toolholding systems that accept the ER40 collet standard.

Installation Notes

Installation is performed by qualified machinists or toolroom technicians. Power down and lock out the spindle before inserting or removing collets. Ensure the collet bore, chuck taper, and clamping nut threads are clean and free of chips or debris before assembly. Use the appropriate ER40 torque wrench or spanner to seat the clamping nut — do not use improvised tools that may damage the collet or chuck threads.