Osg 1101600703 Spiral Point Tap 1/4-20 Unc Plug H3 Nitride

Product Description

The OSG 1101600703 is a spiral point tap designed for threading 1/4-20 UNC holes in production and job-shop environments. It features a plug chamfer for starting in through-holes and a 3-flute spiral point geometry that pushes chips forward ahead of the cutting action, keeping the flutes clear during the cut. The tap is manufactured from vanadium high-speed steel (HSS-E) and finished with a nitride coating to improve surface hardness and reduce friction. It carries an H3 thread limit for a 3B class of fit, making it suitable for standard tolerance fastener applications. Licensed machinists and tool-and-die technicians are the primary users.

This tap is intended for right-hand threading in through-hole applications. The spiral point design is particularly effective in materials such as aluminum and cast aluminum, where chip evacuation is critical to maintaining thread quality. The plug chamfer requires a through-hole or sufficient clearance below the thread for chip ejection. At 3.146 inches overall length with a 0.594-inch thread length, it is sized for standard hand-tap holders, CNC tapping heads, and drill press setups running at controlled feed rates.

Key Features

• Spiral point geometry pushes chips forward, reducing re-cutting and tap breakage in through-hole work
• Vanadium high-speed steel (HSS-E) construction provides elevated heat and wear resistance over standard HSS
• Nitride coating lowers friction and extends tool life, especially in non-ferrous materials
• H3 thread limit holds 3B class of fit for standard tolerance fastener threads
• Plug chamfer with 3 flutes balances cutting load and suits machine tapping applications
• Right-hand thread direction, no coolant-through requirement, compatible with flood or mist coolant delivery

Compatibility

Designed for threading 1/4-20 UNC through-holes in aluminum and cast aluminum. Suited for use with standard straight-shank tap holders and synchronous tapping attachments that accept a 0.255-inch shank diameter.

Installation Notes

Installation should be performed by a qualified machinist following standard tapping procedures. Secure the workpiece before engaging the tap, and ensure the tap is aligned perpendicular to the workpiece surface to prevent thread runout or tap breakage. Power down or de-energize the machine spindle before loading or removing the tap from the holder. Use an appropriate cutting fluid or coolant rated for the workpiece material; dry tapping aluminum is not recommended with this geometry.