Osg 1754808 Spiral Flute Tap 8-32 Unc Modified Bottoming

Product Description

The OSG 1754808 is a spiral flute tap designed for threading 8-32 UNC holes in demanding materials. Built from powdered metal and finished with a TiCN (titanium carbonitride) coating, this tap handles alloy steel, stainless steel, hardened steel, titanium, and high-nickel alloys where standard high-speed steel tooling falls short. The modified bottoming chamfer allows threading closer to the bottom of blind holes. With a 15-degree helix angle and right-hand flute direction, the spiral geometry evacuates chips up and out of the hole during the tapping cycle, reducing the risk of chip packing in deep or tight applications. Licensed machinists and tool-room technicians are the primary users of this tap.

This tap is suited for production and job-shop environments where difficult-to-machine materials are common. The 8-32 UNC thread form is widely used in instrumentation, fastener assemblies, and light mechanical components. The modified bottoming chamfer makes it appropriate for blind-hole applications where full thread depth near the bottom of the hole is required. The H5 thread limit designation indicates a controlled oversize tolerance that accommodates coatings and maintains dimensional accuracy in tighter fits.

Key Features

• TiCN coating improves wear resistance and lubricity for extended tool life in hard and abrasive materials
• Powdered metal substrate provides uniform grain structure and higher toughness than conventional HSS
• Modified bottoming chamfer enables threading near the base of blind holes
• 15-degree helix angle promotes upward chip evacuation during cutting
• H5 thread limit for controlled oversize tolerance — compatible with standard 8-32 UNC fit classes
• Right-hand thread and right-hand flute direction for standard CW tapping operations

Compatibility

Designed for use in 8-32 UNC tapping applications in alloy steel, stainless steel, hardened steel, titanium, and high-nickel alloy workpieces. Fits standard tap holders and tapping chucks accepting a 0.168-inch shank diameter with a 0.131-inch square drive.

Installation Notes

This tap is installed by machinists or toolroom technicians using a tapping machine, CNC machining center, or hand tap wrench rated for the shank diameter. Ensure the correct tap drill size for 8-32 UNC is used prior to tapping. Secure the workpiece and verify spindle alignment before engaging the tap to prevent breakage. Cutting fluid or tapping compound appropriate for the workpiece material should be applied throughout the operation.