Collis Tool 78928 Tapping Adapter No. 12 Tap No. 2

Product Description

The COLLIS TOOL 78928 is a quick-change tapping adapter designed for use with No. 12 taps in a No. 2 adapter size. It accepts a tap shank diameter of 0.22 inches and a tap square size of 0.165 inches, providing a secure, precise fit for rigid or floating tapping operations on CNC machining centers, drill presses, and tapping machines. The through-coolant design channels cutting fluid directly to the tap, reducing heat buildup and extending tap life in ferrous and non-ferrous materials. Machinists and toolroom technicians rely on this adapter to maintain accurate thread depth and consistent torque transfer in production environments.

This adapter is suited for production tapping applications in job shops, manufacturing cells, and maintenance departments where No. 12 thread sizes are common. The quick-change interface allows operators to swap taps at the spindle without removing the entire holder, reducing cycle time on multi-tap operations. Through-coolant compatibility makes it appropriate for blind-hole and deep-hole tapping where flood coolant alone is insufficient to clear chips and control temperature.

Key Features

• Quick-change design for fast tap exchanges at the spindle without full holder removal
• Through-coolant capability channels fluid directly to the cutting edge for improved tap life
• 0.22-inch tap shank diameter and 0.165-inch tap square size for a precise No. 12 tap fit
• 0.32-inch projection keeps the tap close to the holder for reduced deflection
• 0.95-inch tap depth accommodates standard No. 12 tap shank engagement
• 1.88-inch flange diameter provides stable seating in the tapping head

Compatibility

Designed for use with No. 12 taps in No. 2 tapping adapter applications on quick-change tapping heads and compatible CNC or manual tapping systems that accept through-coolant tooling.

Installation Notes

Installation should be performed by a qualified machinist or toolroom technician. Ensure the spindle is fully stopped and the machine is in a safe, locked-out state before mounting or removing the adapter. Verify that the coolant supply line is connected and free of blockages before engaging through-coolant flow. Confirm tap shank and square dimensions match the adapter specifications before securing the tap to avoid slippage during operation.