Osg 1747301 Spiral Flute Tap 8-32 Unc Modified Bottoming

Product Description

The OSG 1747301 is a spiral flute tap designed for cutting 8-32 UNC internal threads in a range of ferrous materials. It features a 45-degree helix angle that evacuates chips upward during blind-hole tapping, reducing the risk of chip packing and tap breakage. Manufactured from vanadium high-speed steel with a steam oxide coating, it delivers added lubricity and corrosion resistance during cutting. The modified bottoming chamfer allows threading close to the bottom of a blind hole. With a 2B class of fit and H7 thread limit, it produces threads that meet standard fastener tolerances for general mechanical assembly work.

This tap is suited for production and maintenance tapping in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel. The 8-32 UNC size is common in instrument panels, electronic enclosures, small structural brackets, and precision mechanical assemblies. The 3-flute spiral design performs well in both CNC tapping centers and hand-tapping operations where chip control in blind holes is a priority. It is sold individually and is appropriate for machine shops, maintenance facilities, and trade professionals working with small-diameter threaded fastener applications.

Key Features

• 45-degree right-hand helix angle for upward chip evacuation in blind holes
• Modified bottoming chamfer for threading close to hole bottom
• Vanadium high-speed steel construction for durability in ferrous materials
• Steam oxide coating improves lubricity and reduces galling
• 2B class of fit with H7 thread limit for standard fastener tolerance compliance
• Right-hand thread cutting direction, 3 flutes

Compatibility

Rated for use in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel. Designed for 8-32 UNC thread form per Series 303 specifications.

Installation Notes

Installation should be performed by a machinist or qualified technician familiar with tapping operations. Secure the workpiece fully before tapping and use an appropriate cutting fluid for the material being tapped. For machine tapping, verify spindle speed and feed rate are appropriate for the tap diameter and material hardness. Inspect the tap for wear or chipping before each use to avoid thread damage or breakage in the workpiece.