Osg 1103600400 Spiral Point Sti Tap 8-32 Unc Hss

Product Description

The OSG 1103600400 is a spiral point STI tap designed for cutting 8-32 UNC threads in through-hole applications. It features a 3-flute spiral point geometry that pushes chips forward ahead of the cutting zone, reducing chip packing and improving thread quality at production speeds. Built from high speed steel with a bright uncoated finish, this tap carries an H2 thread limit and a 3B class of fit, making it suitable for standard-tolerance threaded insert applications. The overall length is 2-3/8 inches (2.382 inches decimal) with a shank diameter of 0.22 inches. It weighs 0.025 pounds. Licensed machinists, toolroom technicians, and maintenance trade professionals use this tap when preparing holes to receive STI-style threaded inserts.

This tap is used in applications requiring 8-32 UNC tapped holes sized for STI (screw thread insert) inserts, such as Heli-Coil or equivalent systems. It is appropriate for through-hole tapping in ferrous and non-ferrous metals where chip evacuation matters and thread quality must meet 3B tolerance standards. The modified bottoming chamfer allows threading closer to the bottom of a blind hole than a standard plug chamfer while still providing enough lead-in to start the tap cleanly. Typical applications include maintenance and repair operations, precision machining, and production environments working with insert-reinforced threads.

Key Features

• Spiral point geometry pushes chips forward for clean through-hole tapping
• 8-32 UNC thread size with H2 thread limit and 3B class of fit
• 3 flutes for balanced cutting and chip clearance
• Modified bottoming chamfer for tapping close to blind hole bottoms
• High speed steel construction for durability across ferrous and non-ferrous materials
• Bright uncoated finish suitable for use with standard tapping fluids

Compatibility

Designed as an OEM-style STI tap for use in 8-32 UNC through-hole and near-bottom blind-hole applications requiring a 3B class of fit with H2 thread limit, compatible with standard STI insert systems for that thread size.

Installation Notes

This tap should be installed and operated by a qualified machinist or maintenance professional familiar with tapping speeds, feeds, and cutting fluid requirements for the workpiece material. Always ensure the workpiece is securely clamped and the tap is properly aligned before engaging the cut to avoid tap breakage or thread damage. Use an appropriate tapping fluid for the material being threaded. Disconnect or lock out power on any machine tool before changing tooling per applicable safety procedures.