Collis Tool 78918 Tapping Adapter 7/16 Inch Tap

Product Description

The COLLIS TOOL 78918 is a quick-change tapping adapter designed to hold 7/16 inch taps in compatible tap holders and CNC tapping heads. It accepts taps with a shank diameter of 0.323 inches and a tap square size of 0.242 inches, conforming to Adapter Size No. 1 specifications. The unit supports through-coolant delivery, allowing cutting fluid to pass directly through the adapter body to the tap for improved chip evacuation and tool life in production tapping operations. Machinists, toolroom technicians, and CNC operators install this adapter in machine shop environments where repeatable tap changes and coolant-fed tapping cycles are required.

This adapter is suited for production and job-shop tapping applications on machining centers, CNC lathes, and dedicated tapping machines. It is appropriate for both ferrous and non-ferrous materials where through-coolant is advantageous. The quick-change design reduces setup time between tap changes, making it a practical choice for high-volume or multi-feature parts. A flange diameter of 1.18 inches and a tap depth of 1.06 inches provide solid registration and adequate tap engagement depth for standard threading operations.

Key Features

• Accepts 7/16 inch taps with 0.323 inch shank diameter and 0.242 inch tap square size
• Quick-change interface for fast, repeatable tap changes without tools
• Through-coolant capable for direct fluid delivery to the cutting edge
• Tap Adapter Size No. 1 for compatibility with standard quick-change tap holder systems
• 1.18 inch flange diameter provides stable seating in the holder body
• 1.06 inch tap depth and 0.28 inch projection for controlled tap engagement

Compatibility

Designed for use with quick-change tap holder systems that accept Tap Adapter Size No. 1 and support through-coolant functionality. Verify holder bore and coolant port alignment with your specific machine tool setup before installation.

Installation Notes

Installation should be performed by a qualified machinist or toolroom technician familiar with quick-change tooling systems. Always power down and lock out the machine spindle before inserting or removing tapping adapters. Confirm through-coolant port alignment between the adapter and holder body prior to running coolant. Do not force the tap shank into the adapter; verify square size and shank diameter match the adapter specifications before assembly.