Value Collection 230-4121 5C Steel Collet 21/64 in

Product Description

The VALUE COLLECTION 230-4121 is a 5C round collet machined from steel for use in 5C-compatible collet chucks, collet closers, and indexing fixtures. It holds round workpieces at a nominal bore size of 21/64 inch with a total indicator runout (TIR) of 0.0005 inch, making it suitable for precision turning, milling, and grinding operations where concentricity matters. The internal thread measures 1.041 inch-24 and the external thread measures 1.242 inch-20, matching the standard 5C collet thread specification. The collet weighs 0.59 pounds. Machinists and toolroom technicians are the primary users of this part.

This collet is intended for use in manual and CNC lathes, milling machines, and rotary indexing heads equipped with a 5C spindle. It is well suited for production environments and job shops that require repeatable workholding on small-diameter round stock. The 21/64 inch bore size accommodates round bar stock at that diameter and is a common size in both imperial-measurement production lines and toolroom setups. Package quantity is one collet per order.

Key Features

• 21/64 inch bore for round workpieces
• 0.0005 inch TIR for high-concentricity workholding
• Steel construction for durability under repeated clamping cycles
• 1.041 inch-24 internal thread matches standard 5C collet closer engagement
• 1.242 inch-20 external thread for standard 5C chuck compatibility
• Single-piece collet design with no additional components required

Compatibility

Designed as an OEM-style replacement or direct-fit collet for standard 5C collet chucks, collet closers, and 5C indexing fixtures that accept the 1.041 inch-24 internal and 1.242 inch-20 external thread specification.

Installation Notes

Installation is performed by a machinist or toolroom technician. The machine spindle must be brought to a complete stop and all energy sources locked out before inserting or removing a collet. Inspect the collet bore and taper seating surfaces for chips or burrs before installation, as contamination will increase runout beyond the rated 0.0005 inch TIR. Do not exceed the rated bore size by forcing oversized stock into the collet, as this will permanently deform the collet segments.