Osg 1232205 Spiral Point Tap 7/16-20 Unf Tin Hss

Product Description

The OSG 1232205 is a spiral point plug tap designed for threading operations in a wide range of ferrous and non-ferrous materials. It cuts a 7/16-20 UNF right-hand thread and carries a 3B class of fit with an H3 thread limit, making it suitable for through-hole tapping applications where chip ejection ahead of the cut is required. The body is manufactured from high-speed steel and finished with a titanium nitride (TiN) coating that increases surface hardness and extends tool life in production environments. Overall length is 3.156 inches, with a thread length of 0.882 inches and a shank diameter of 0.323 inches. Licensed machinists and toolroom technicians are the primary users.

This tap is suited for through-hole threading in both manual and CNC tapping operations. The spiral point geometry pushes chips forward and out of the hole, making it effective in production runs on materials including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel. The TiN coating provides additional wear resistance when running at higher speeds or in abrasive materials. It fits standard tap holders and chucks sized for the 0.323-inch shank diameter common to this tap series.

Key Features

• 7/16-20 UNF thread form with H3 thread limit and 3B class of fit
• 3-flute spiral point geometry ejects chips forward for clean through-hole tapping
• TiN coating increases surface hardness and extends tool life versus uncoated HSS
• High-speed steel construction handles a broad range of workpiece materials
• Right-hand cut, plug chamfer for standard through-hole starting and threading
• No coolant-through design; suitable for flood coolant or cutting oil applied externally

Compatibility

Designed for use in standard tap holders and tapping heads accepting a 0.323-inch shank diameter. Compatible workpiece materials include aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, high-carbon steel, and hardened steel as specified by the manufacturer for OSG Series 105.

Installation Notes

This tap should be installed by a qualified machinist or toolroom technician familiar with tapping speeds, feeds, and cutting fluid requirements for the workpiece material. Secure the tap in a properly sized holder or chuck before operation and confirm spindle direction matches the right-hand thread designation. Apply an appropriate cutting fluid or tapping compound to the work area before starting the cut. Inspect the tap for chipping or wear after extended use, particularly when working hardened steel, and replace before dimensional tolerance is compromised.