Osg 1734908 Spiral Point Tap 4-40 Unc Ticn Hss

Product Description

The OSG 1734908 is a spiral point tap designed for cutting 4-40 UNC internal threads in a range of ferrous materials. Built from vanadium high speed steel with a TiCN coating, this plug-chamfer tap pushes chips forward ahead of the cut to maintain clean, unobstructed flute channels. It features a 2-flute design, a right-hand thread direction, and an H5 thread limit for consistent tolerance control in production and maintenance applications. With an overall length of 1.874 inches and a thread length of 0.33 inches, this tap is sized for compact fastener applications. Licensed HVAC, plumbing, and mechanical technicians use spiral point taps when threading new holes or repairing threaded fastener bores in equipment enclosures and mounting hardware.

The OSG 1734908 is suited for through-hole tapping operations where chip evacuation forward is practical. Rated for use in hardened steel, low-carbon steel, medium-carbon steel, and stainless steel, this tap fits both light production runs and field service work where a 4-40 UNC thread is required. The plug chamfer provides a gradual thread lead-in, making it appropriate for initiating threads from the beginning of a hole without a starter tap. It is part of the OSG Series 300 and carries an oversize designation to account for material spring-back in the finished thread.

Key Features

• TiCN coating reduces friction and extends tool life in ferrous materials including stainless steel
• Vanadium high speed steel construction provides hardness and wear resistance beyond standard HSS
• Spiral point geometry pushes chips forward, keeping flutes clear during through-hole tapping
• Plug chamfer with H5 thread limit delivers controlled thread tolerance for consistent fastener fit
• 2-flute design suited for smaller diameter taps in tight-clearance applications
• Right-hand thread direction, oversize designation accounts for material spring-back

Compatibility

Designed for use in through-hole tapping of 4-40 UNC threads in hardened steel, low-carbon steel, medium-carbon steel, and stainless steel workpieces. Compatible with standard tap handles and power tap drivers accepting a 0.141-inch shank diameter.

Installation Notes

Spiral point taps should be installed in a properly sized and drilled tap drill hole before threading begins. Secure the workpiece and ensure the tap is aligned perpendicular to the hole to avoid thread misalignment or tap breakage. Apply cutting fluid appropriate for the workpiece material, particularly when tapping stainless steel. Use appropriate tap holders rated for the tap shank diameter and follow standard machining or hand-tapping practices for small-diameter taps.