Collis Tool 79317 Tapping Adapter 3/8 Inch Tap

Product Description

The COLLIS TOOL 79317 is a quick-change tapping adapter designed to hold and drive 3/8 inch taps in CNC machining centers, drill presses, and tapping machines. It accepts taps with a shank diameter of 0.381 inches and a square drive size of 0.286 inches, providing a secure, positive drive connection during threading operations. The adapter features a flange diameter of 1.26 inches and a tap depth of 1.05 inches, making it suitable for production-level tapping applications where fast, repeatable tool changes are required. This unit does not support coolant-through configurations.

This tapping adapter is used in metalworking and machining environments where operators need to quickly swap tapping tools without removing the entire holder assembly. It is well suited for job shops, production floors, and maintenance machine shops running repetitive threading cycles. The quick-change design reduces setup time and keeps tapping operations consistent across multiple workpieces. It is installed and used by machinists and tool-room professionals working with standard tapping equipment.

Key Features

• Quick-change design allows fast tap swaps without full holder removal
• Accepts 3/8 inch tap size with 0.381 inch tap shank diameter
• Tap square size of 0.286 inches provides positive drive engagement
• Projection of 0.98 inches and tap depth of 1.05 inches for reliable reach
• Flange diameter of 1.26 inches for stable seating in the holder body
• Coolant-through not supported - dry or flood coolant via external means only

Compatibility

Designed as a direct-fit tapping adapter for 3/8 inch taps with standard shank and square dimensions in quick-change tapping systems that accept a number 1 adapter size.

Installation Notes

Installation and tool changes should be performed by a qualified machinist with the spindle fully stopped and the machine in a safe, locked-out state. Verify that the tap shank diameter and square size match the adapter specifications before seating the tap. Standard shop practices under applicable ANSI and OSHA machining safety guidelines apply. Do not attempt to force-fit taps that do not match the specified shank or square dimensions, as this can damage the adapter drive surfaces.