Value Collection 230-4399 5C Emergency Collet 1/8 Inch

Product Description

The VALUE COLLECTION 230-4399 is a 5C emergency collet designed for lathe and spindle workholding applications where a custom or field-bored solution is required. Emergency collets ship with an unbored or soft pilot hole, allowing machinists to bore the collet on-site to the precise diameter needed for a specific workpiece. This unit features a 1/8 inch pilot hole, an internal thread size of 1.041 inches at 24 threads per inch, and an external thread size of 1.242 inches at 20 threads per inch. Constructed from steel, it is suited for general-purpose turning, grinding, and secondary machining operations. Total indicated runout (TIR) is 0.00315 inches, supporting accurate concentricity once properly bored and seated.

This collet fits standard 5C spindle-nose collet closers and collet chucks found on lathes, grinding machines, and dedicated 5C collet fixtures in both job shop and production environments. The emergency style makes it the go-to choice when a standard 5C collet in the required bore size is not available, or when a non-standard diameter or special grip configuration must be machined in-house. Machinists in tool rooms, production cells, and maintenance shops routinely keep emergency collets on hand for quick-turn setups.

Key Features

• Emergency-style 5C collet — pilot hole is field-borable to a custom diameter
• 1/8 inch pilot hole size for initial setup and boring reference
• TIR of 0.00315 inches for reliable concentricity after boring
• Steel construction for durability in production and tool-room use
• Internal thread size 1.041 inches at 24 TPI; external thread size 1.242 inches at 20 TPI
• Single-piece unit — no assembly required before boring

Compatibility

Designed for use with standard 5C collet closers, collet chucks, and 5C fixture blocks. Confirm that the closer or chuck accepts a 1.242 inch at 20 TPI external thread before installation.

Installation Notes

Installation and boring of emergency collets is performed by a machinist using a lathe or grinding setup with a proper collet closer or fixture. Power down and de-energize the machine spindle before seating or removing the collet. Bore the pilot hole to final diameter in small increments, checking fit against the workpiece frequently to avoid overboring. Follow applicable shop safety standards and machine manufacturer guidelines during all boring operations.