Value Collection MSC-81137820 Spiral Point Tap 1/4-20 Unc

Product Description

The VALUE COLLECTION MSC-81137820 is a spiral point tap designed to cut internal threads in through-hole applications. Built from high speed steel (HSS) with a bright, uncoated finish, this plug chamfer tap pushes chips forward ahead of the cutting edge, making it well suited for through-hole threading in a wide range of materials. It cuts a 1/4-20 UNC right-hand thread and is ground to an H7 thread limit for consistent dimensional accuracy. Machinists, tool-and-die technicians, and maintenance professionals use this style of tap for production and repair threading operations on manual machines and CNC equipment alike.

This tap is intended for through-hole threading in ferrous and non-ferrous materials where chip evacuation forward through the hole is practical. The plug chamfer — typically 3 to 5 threads — allows the tap to start easily and is the most common choice for general-purpose through-hole work in manufacturing, fabrication, and maintenance environments. It is not designed for blind-hole applications where chip packing is a concern.

Key Features

• 1/4-20 UNC thread form — one of the most common inch-series thread standards in industrial and commercial applications
• Spiral point geometry pushes chips forward, reducing chip clogging in through-hole operations
• H7 thread limit provides a controlled fit tolerance suitable for standard fastener clearances
• High speed steel construction offers good wear resistance and toughness across a range of workpiece materials
• Bright uncoated finish — no added coating to alter tap geometry or introduce thermal variability
• Right-hand thread direction for standard cutting rotation

Compatibility

Designed for through-hole tapping of 1/4-20 UNC threads in applications requiring an H7 thread limit. Suitable for use in standard tap handles, tap wrenches, and CNC rigid tapping setups configured for 1/4-20 tooling.

Installation Notes

This tap is installed by machinists and maintenance technicians using standard tapping equipment. Ensure the workpiece is securely fixtured and the tap is properly aligned with the pilot hole before engaging the cut. Use an appropriate cutting fluid or tapping compound for the workpiece material to extend tool life and improve thread quality. Inspect the tap for chipping or wear before each use — a damaged tap can strip threads or break in the hole.