Value Collection 204-4056 ER40 Collet 7/8 Inch

Product Description

The VALUE COLLECTION 204-4056 is an ER40 series collet machined to a 0.8748 inch (7/8 inch) bore size with a total indicator runout (TIR) of 0.0005 inches. ER collets are precision workholding components used in CNC machining centers, manual mills, and lathes to grip cutting tools or round stock concentrically within a collet chuck. The tight TIR rating on this collet supports accurate material removal and consistent tool positioning during cutting operations. Machinists and tool-room technicians select ER40 collets when the application requires a mid-to-large bore capacity within the widely standardized ER collet system. The part weighs 0.44 pounds.

This collet is suited for use in ER40-compatible collet chucks mounted on vertical machining centers, horizontal mills, CNC lathes, and similar machine tool spindles. The 7/8 inch bore accommodates standard shank tooling and round stock at that diameter. It is used in job shops, production facilities, and tool rooms wherever repeatable tool holding is required at the ER40 bore size. Installation and removal follow standard ER collet procedures using a torque wrench and the appropriate ER40 collet nut and chuck body.

Key Features

• ER40 collet series — fits any ER40-compatible chuck body
• 0.8748 inch (7/8 inch) bore for standard shank tooling and round stock
• 0.0005 inch TIR for precise, concentric tool holding
• Lightweight at 0.44 pounds for easy handling and quick changeover
• Single-piece collet construction standard to the ER system

Compatibility

Designed for use in ER40-compatible collet chucks across standard CNC and manual machine tool platforms that accept the ER40 collet series.

Installation Notes

ER collets are installed and removed by qualified machinists or tool-room technicians. Before changing collets, power down the machine spindle and confirm the spindle has come to a full stop. Seat the collet fully into the collet nut before threading the nut onto the chuck body, and use a calibrated torque wrench with the correct ER40 collet nut spanner to achieve proper clamping force. Do not use an undersized or oversized collet to grip a tool shank — always match the collet bore to the actual tool shank diameter.