Osg 0137701 Spiral Flute Tap 5/16-24 Unf Bottoming 3B Hss

Product Description

The OSG 0137701 is a spiral flute bottoming tap designed for cutting internal 5/16-24 UNF threads in a wide range of steel materials. Manufactured from vanadium high-speed steel with a steam oxide coating, it delivers durability and reduced friction during tapping operations. The 45-degree helix angle on the spiral flute design pulls chips up and out of the hole, making it well-suited for blind-hole applications where chip evacuation is critical. With a 3B class of fit and H3 thread limit, it produces threads to tight dimensional tolerances expected in precision fastener applications. Machinists and toolmakers are the primary users of this tap.

This tap is intended for use in ferrous materials including stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel. The bottoming chamfer allows threading close to the bottom of a blind hole, a requirement common in fixture work, tooling fabrication, and mechanical assembly. It is sized for 5/16-24 UNF threads, a fine-thread specification frequently found in precision mechanical and industrial applications. The right-hand thread direction and right-hand flute orientation are standard for conventional CNC and manual tapping setups.

Key Features

• 45-degree helix angle promotes efficient chip evacuation in blind holes
• Bottoming chamfer allows threading to the base of blind bores
• Vanadium high-speed steel construction for wear resistance in steel materials
• Steam oxide coating reduces friction and improves lubrication retention
• H3 thread limit and 3B class of fit for consistent, tolerance-controlled threads
• Right-hand cut, right-hand spiral flute configuration for standard tapping operations

Compatibility

Rated for use in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel. Designed for 5/16-24 UNF blind-hole tapping applications on manual or CNC tapping equipment.

Installation Notes

This tap is installed and operated by machinists or toolmakers using a tapping head, CNC machining center, or manual tap wrench. Always apply an appropriate cutting fluid for the workpiece material before and during tapping. Ensure the workpiece is fully secured before starting the operation. Coolant-through is not supported on this tap, so external lubrication is required.