Osg 1740305 Spiral Point Tap 8-32 Unc Tin Hss

Product Description

The OSG 1740305 is a spiral point plug tap designed for threading 8-32 UNC holes in production and repair applications. Built from vanadium high-speed steel (HSS-E) with a titanium nitride (TiN) coating, it delivers extended tool life and reduced friction compared to uncoated taps. The 3-flute spiral point geometry pushes chips forward ahead of the cutting zone, making it well suited for through-hole tapping operations. With an overall length of 2.126 inches, a thread length of 0.374 inches, and a shank diameter of 0.168 inches, it fits standard tap holders and machine setups used by machinists and maintenance trades alike.

This tap is rated for right-hand threading to a 2B class of fit with an H3 thread limit, which is appropriate for standard tolerance fastener applications. It is suited for both manual and CNC machine tapping in through-hole configurations. The material compatibility list covers a broad range of ferrous and non-ferrous metals including aluminum, low-carbon steel, medium-carbon steel, high-carbon steel, alloy steel, die steel, cast iron, and stainless steel, making it a versatile tap for job shop and MRO use. Coolant-through is not supported on this model.

Key Features

• 8-32 UNC thread form, 2B class of fit, H3 thread limit for standard tolerance applications
• Spiral point geometry pushes chips forward, ideal for through-hole tapping
• 3-flute design balances chip clearance and cutting stability
• Vanadium HSS-E construction for improved wear resistance over standard M2 HSS
• TiN coating reduces friction and extends tool life across a wide range of work materials
• Plug chamfer provides easy thread entry and smooth cutting action

Compatibility

Designed for right-hand through-hole tapping in materials including aluminum, stainless steel, alloy steel, die steel, cast iron, and low-, medium-, and high-carbon steel. Fits standard tap holders sized for a 0.168-inch shank diameter.

Installation Notes

Tap installation should be performed by a qualified machinist or maintenance technician. Always secure the workpiece and ensure the tap is properly aligned with the pilot hole before beginning the threading operation. Use an appropriate tapping fluid or cutting oil for the work material to maximize tool life and thread quality. For machine tapping, verify spindle speed and feed rate are appropriate for the material and tap geometry before starting the cycle.