Osg 1251702 Spiral Flute Pipe Tap 3/8-18 Npt Hss

Product Description

The OSG 1251702 is a spiral flute pipe tap designed to cut 3/8-18 NPT threads in through or blind holes where chip evacuation is a priority. The spiral flute geometry pulls chips up and out of the hole, reducing clogging in ductile metals. Built from high-speed steel with an elektraLUBE finish, it delivers improved lubricity and extended tool life compared to uncoated taps. The bottoming chamfer allows threading close to the bottom of a hole. With 4 flutes and a 15-degree helix angle, this tap suits machinists, pipefitters, and maintenance technicians cutting pipe threads in production or field repair settings.

This tap is used to cut NPT tapered pipe threads in a range of materials including steel, aluminum, and cast iron. The bottoming chamfer makes it well suited for blind-hole applications where a standard or plug chamfer would leave too many unthreaded threads at the base. It is commonly used in HVAC, plumbing, and industrial maintenance shops to tap pipe fittings, manifolds, valve bodies, and pressure ports. The right-hand flute direction is compatible with standard right-hand tap holders and CNC tapping cycles.

Key Features

• 3/8-18 NPT thread form for tapered pipe thread applications
• Spiral flute design evacuates chips upward, reducing tap breakage in blind holes
• Bottoming chamfer for threading close to the bottom of a hole
• High-speed steel construction provides toughness across a range of workpiece materials
• elektraLUBE finish improves lubricity and reduces built-up edge
• 4 flutes with 15-degree helix angle for controlled chip flow

Compatibility

Designed as an OEM-style replacement or direct-fit tap for standard 3/8-18 NPT tapping operations using right-hand tap holders, adjustable tap wrenches, or CNC tapping attachments.

Installation Notes

Installation should be performed by a qualified machinist or pipefitter familiar with NPT tapping procedures. Secure the workpiece firmly before tapping and use a suitable cutting fluid for the workpiece material. Always back the tap out periodically to break and clear chips, especially in deeper holes. Follow applicable shop safety practices and ensure the tap holder provides proper axial alignment to prevent tap breakage.