Accupro 40103-01T Spiral Flute Tap 5/16-18 Unc Tin Coated

Product Description

The ACCUPRO 40103-01T is a spiral flute tap designed for threading 5/16-18 UNC holes in production and maintenance machining applications. It features a modified bottoming chamfer, 3 right-hand spiral flutes with a 42-degree helix angle, and a TIN (titanium nitride) coating over a powdered metal substrate. The high helix angle pulls chips up and out of the hole, making this tap well suited for blind-hole tapping in tough or stringy materials. The TIN coating reduces friction and extends tool life compared to uncoated taps. Overall length is 2-23/32 inches. Thread class of fit is 3B with an H3 thread limit, producing threads to standard tolerance for general fastener fitment.

This tap is used in machine shops, toolrooms, and maintenance environments where 5/16-18 UNC internal threads are required. The modified bottoming chamfer allows threading closer to the bottom of a blind hole than a standard taper or plug chamfer. It is appropriate for use in CNC tapping centers, drill presses with a tapping attachment, or manual machine tools. Coolant-through is not supported. Right-hand flute direction matches the right-hand thread direction, consistent with standard tapping practice for most ferrous and non-ferrous workpiece materials.

Key Features

• 5/16-18 UNC thread form with 3B class of fit and H3 thread limit
• 42-degree right-hand spiral flute geometry for efficient chip evacuation in blind holes
• Modified bottoming chamfer allows threading near the bottom of a blind hole
• TIN coating reduces friction and increases tool life over uncoated taps
• Powdered metal construction provides consistent hardness and wear resistance
• 2-23/32 inch overall length suits standard tap holders and tapping heads

Compatibility

Designed as a direct-fit replacement or standard tooling selection for 5/16-18 UNC tapping operations using conventional tap holders, collet chucks, or tapping heads that accept industry-standard shank dimensions for this tap size.

Installation Notes

A licensed machinist or qualified toolroom technician should mount this tap in a properly sized tap holder or tapping attachment before use. Ensure the spindle speed and feed rate are set per the workpiece material before starting the cut. Secure the workpiece fully before tapping to prevent movement. Inspect the tap for chipping or wear before each use and replace if the cutting edges show visible damage.