Osg 1701801 Spiral Point Tap 5/8-18 Unf 3 Flute

Product Description

The OSG 1701801 is a spiral point plug tap designed for threading 5/8-18 UNF internal threads in demanding materials. It features a 3-flute spiral point geometry that pushes chips forward ahead of the cut, keeping the thread zone clear and reducing the risk of chip packing in blind and through holes. Built from powdered metal with a steam oxide coating, this tap handles elevated cutting loads and resists galling in tough workpiece materials. The plug chamfer provides a gradual thread entry suitable for through-hole applications. Overall length is 3.811 inches with a thread length of 1.118 inches and a shank diameter of 0.48 inches.

This tap is suited for production and maintenance machining operations where 5/8-18 UNF threads are required. It is rated for use in hardened steel, stainless steel, high-nickel alloy, titanium, alloy steel, and die steel — materials common in aerospace, tooling, and heavy industrial fabrication work. The H5 thread limit and 2B class of fit deliver the tolerance stack typical of standard fastener and mechanical assembly applications. Right-hand thread direction is standard for conventional tapping setups.

Key Features

• Spiral point geometry pushes chips forward, reducing packing in through-hole applications
• Powdered metal construction provides increased toughness and wear resistance over standard HSS
• Steam oxide coating reduces friction and improves lubrication retention during cutting
• Plug chamfer allows gradual thread engagement for through-hole tapping
• H5 thread limit with 2B class of fit for standard tolerance fastener threads
• Rated for hardened steel, stainless steel, titanium, high-nickel alloy, alloy steel, and die steel

Compatibility

Designed for tapping 5/8-18 UNF through holes in hardened steel, stainless steel, high-nickel alloy, titanium, alloy steel, and die steel. Series 312 tap compatible with standard tap holders and tapping chucks accepting a 0.48-inch shank diameter.

Installation Notes

Installation is performed by machinists or maintenance technicians using a tapping machine, CNC machining center, or hand tap wrench with appropriate torque control. Ensure the workpiece is securely fixtured and the tap is properly aligned to the drilled hole centerline before engagement. Use a cutting fluid or tapping compound rated for the workpiece material, particularly when tapping stainless steel, titanium, or high-nickel alloys, to extend tap life and prevent galling. Inspect the tap for chipping or wear before each use; do not force a dull or damaged tap.