Osg 2530801 Spiral Point Tap 5/16-18 Unc Plug H2 Hss

Product Description

The OSG 2530801 is a spiral point plug tap designed for cutting 5/16-18 UNC right-hand threads in through-hole applications. Built from vanadium high-speed steel (HSS-E) with a steam oxide coating, it delivers reliable wear resistance and reduced friction in production and maintenance threading work. The plug chamfer provides a gradual thread lead-in, making it well suited for through-hole tapping where chip ejection ahead of the tap is required. With 3 flutes, an H2 thread limit, and a 2B class of fit, this tap produces threads that meet standard fastener assembly tolerances. Overall length is 3.543 inches (90 mm) with a thread length of 1.125 inches.

The OSG 2530801 is appropriate for use in a wide range of metalworking applications including production tapping, maintenance and repair operations (MRO), and fabrication shops. The steam oxide finish improves lubricity and corrosion resistance during use. Compatible material applications include aluminum, low-carbon steel, medium-carbon steel, high-carbon steel, alloy steel, die steel, cast iron, and stainless steel. It is used by machinists, toolroom technicians, and maintenance trades requiring consistent 5/16-18 UNC thread quality in through-hole work.

Key Features

• Spiral point geometry pushes chips forward through the hole, reducing clogging in through-hole tapping
• Vanadium HSS-E construction provides increased toughness and heat resistance over standard M2 HSS
• Steam oxide coating reduces friction and improves lubricity during cutting
• Plug chamfer (3-5 thread lead) allows gradual thread engagement for smooth starts
• H2 thread limit and 2B class of fit ensure threads meet standard fastener assembly tolerances
• Right-hand thread direction; no coolant-through requirement for general-purpose use

Compatibility

Designed for cutting 5/16-18 UNC right-hand internal threads in through-hole configurations across aluminum, cast iron, low- and medium-carbon steel, high-carbon steel, alloy steel, die steel, and stainless steel workpieces.

Installation Notes

This tap is installed in a tapping chuck, tap wrench, or CNC rigid-tapping holder by a machinist or maintenance technician. Always drill the correct tap drill size for 5/16-18 UNC before tapping and ensure the workpiece is securely fixtured. Apply appropriate cutting fluid or tapping compound for the workpiece material to extend tool life. Never force a tap against resistance; back off periodically to break chips when tapping manually.