Osg 1762501 Spiral Flute Tap 1/2-20 Unf 3 Flute Hss

Product Description

The OSG 1762501 is a spiral flute tap designed for cutting 1/2-20 UNF internal threads in a range of ferrous materials. It features a 45-degree right-hand helix with three flutes and a modified bottoming chamfer, making it suited for threading holes that require thread engagement close to the bottom. The tap is manufactured from vanadium high-speed steel and carries a steam oxide coating for improved lubricity and surface hardness. Thread limit is H7 with a 2B class of fit. Overall length is 2.938 inches and thread length is 0.614 inches. Licensed machinists and toolroom technicians are the typical users of this tooling.

This tap is intended for use in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel workpieces. The modified bottoming chamfer allows threading to within a short distance of a blind hole floor, which is common in automotive, aerospace, and general metalworking applications. The 45-degree helix angle promotes efficient chip evacuation up and out of the hole, reducing the risk of chip packing in deep or semi-blind bores. This is a Series 303 tap from OSG, packaged individually.

Key Features

• 1/2-20 UNF right-hand thread, H7 thread limit, 2B class of fit
• 45-degree spiral flute helix for upward chip evacuation in blind and semi-blind holes
• Modified bottoming chamfer allows threading close to the bottom of a blind hole
• Vanadium high-speed steel construction for wear resistance in ferrous materials
• Steam oxide coating improves lubricity and reduces built-up edge
• No coolant-through design; compatible with flood or brush-applied cutting fluid

Compatibility

Rated for use in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel. Designed as an OEM-style cutting tool for 1/2-20 UNF threaded hole applications in general metalworking, toolroom, and production machining environments.

Installation Notes

This tap should be installed in a tapping chuck or rigid holder sized for a 0.381-inch shank diameter. Power down and de-energize any CNC or drill press before changing tooling. Use an appropriate cutting fluid for the workpiece material, especially when tapping stainless steel, to prevent galling and premature wear. Do not exceed the recommended speed and feed for the material being tapped, and back the tap out periodically to clear chips from the flutes when working in deep blind holes.