Osg 8011202 Spiral Flute Sti Tap 1/4-20 Unc Hss

Product Description

The OSG 8011202 is a high speed steel spiral flute tap designed for cutting STI (Screw Thread Insert) threads in a 1/4-20 UNC configuration. It features a 50-degree helix angle that efficiently evacuates chips up and out of the hole during through-hole and blind-hole tapping operations. The bottoming chamfer allows threading close to the bottom of blind holes, making it suitable for applications where full thread depth near the base of a bore is required. The elektraLUBE surface finish provides lubricity to reduce friction and extend tool life in production environments. This tap is intended for use by machinists, maintenance technicians, and tool-room professionals working with ferrous and non-ferrous materials.

The OSG 8011202 is appropriate for creating STI threads used with helical wire inserts such as those commonly installed to repair or strengthen threaded holes in castings, housings, and structural components. It suits both manual tapping operations and machine tapping setups in light manufacturing, MRO, and precision machining environments. The 1/4-20 UNC thread form and H3 thread limit make this tap compatible with standard STI insert specifications at this thread size. It is well suited for job shops, maintenance departments, and production lines where insert-threaded fastener systems are standard practice.

Key Features

• 1/4-20 UNC thread form for STI insert thread preparation
• 50-degree spiral flute helix for efficient chip evacuation in blind and through holes
• Bottoming chamfer allows threading to the base of blind holes
• elektraLUBE finish reduces friction and extends tap service life
• H3 thread limit for consistent fit with standard STI inserts
• High speed steel construction provides toughness across a range of workpiece materials

Compatibility

Designed for use in STI tapping applications requiring a 1/4-20 UNC thread form with an H3 thread limit. Consult the OSG Series 108 tool documentation to confirm compatibility with specific insert systems and machine setups.

Installation Notes

Installation should be performed by a qualified machinist or maintenance technician using a properly aligned tap handle or tapping head. Secure the workpiece firmly before tapping and apply appropriate cutting fluid for the material being machined. When tapping blind holes, use the bottoming chamfer to maximize thread engagement depth without forcing the tap against the hole bottom. Inspect the tap for wear or damage before each use and replace if cutting edges appear dull or chipped.