Value Collection MSC-04540290 Spiral Point Tap 1/4-28 Unf

Product Description

The VALUE COLLECTION MSC-04540290 is a spiral point tap designed for cutting 1/4-28 UNF threads in through-hole and shallow blind-hole applications. Built from high speed steel (HSS) with a bright uncoated finish, this tap is suited for general-purpose threading on steel, aluminum, and similar materials. The bottoming chamfer allows threading close to the bottom of a hole where standard or plug chamfer taps cannot reach. With a 2-flute spiral point geometry, the tap pushes chips forward ahead of the cutting action, reducing clogging in through-hole work. The H3 thread limit ensures consistent fit within the 3B class of fit tolerance range.

This tap is used in machine shop, maintenance, and fabrication environments where 1/4-28 UNF fine-thread forms are required. Bottoming taps are typically the final tap used in a three-tap sequence after a taper and plug tap have started the thread. It is appropriate for production machining, manual tapping, and repair work on threaded fastener holes in metal components. Right-hand thread direction is standard for the vast majority of fastener applications.

Key Features

• Bottoming chamfer for threading close to the bottom of a hole
• Spiral point geometry pushes chips forward, ideal for through-hole tapping
• High speed steel construction provides hardness and wear resistance
• H3 thread limit for 3B class of fit tolerance compliance
• Bright uncoated finish for use across a range of common materials
• Right-hand thread cutting direction

Compatibility

Designed for cutting 1/4-28 UNF right-hand internal threads per Unified National Fine thread standards. Fits standard 1/4-28 tap holders and collets compatible with the tap shank dimensions.

Installation Notes

A licensed machinist or experienced technician should select the correct tap drill size per UNF standards before tapping to ensure proper thread engagement. Secure the workpiece and use appropriate cutting fluid for the material being tapped to extend tool life and improve thread quality. Avoid excessive force when approaching the bottom of a blind hole with a bottoming tap, as the cutting flutes do not extend to the shank and breakage can occur if the tap bottoms out under load. Inspect threads with a 3B go/no-go gauge after tapping to verify dimensional compliance.