Osg 2842801 Spiral Point Tap 1/2-13 Unc 3 Flute

Product Description

The OSG 2842801 is a spiral point plug tap designed for threading 1/2-13 UNC through holes in a wide range of metals. Built from 3% vanadium high-speed steel (HSS-E), it delivers increased wear resistance and edge retention compared to standard HSS taps. The steam oxide coating reduces friction and helps resist corrosion during storage and use. With 3 flutes and a plug chamfer, the tap pushes chips ahead of the cutting edge into the hole, making it well suited for through-hole tapping in production environments. Machinists and toolroom technicians use this tap in manual and CNC tapping applications.

This tap is rated for use in a broad range of workpiece materials including aluminum, low-carbon steel, medium-carbon steel, high-carbon steel, alloy steel, die steel, cast iron, and stainless steel. The H7 thread limit designates a slightly oversized tolerance class, which helps accommodate plating or coating on the finished thread. The plug chamfer provides a gradual lead-in and is best suited for through holes where chip evacuation ahead of the tap is not a concern. Series 280 is OSG's general-purpose vanadium HSS tapping line for industrial use.

Key Features

• 1/2-13 UNC right-hand thread form, H7 thread limit for oversized tolerance class
• 3% vanadium HSS-E construction for extended tool life vs. standard M2 HSS
• Steam oxide coating reduces friction and provides mild corrosion resistance
• Spiral point geometry pushes chips forward, optimized for through-hole tapping
• Plug chamfer with 3 flutes for stable, controlled thread engagement
• Compatible with a wide range of ferrous and non-ferrous workpiece materials

Compatibility

Designed for through-hole tapping of 1/2-13 UNC threads in aluminum, hardened steel, stainless steel, high-carbon steel, low-carbon steel, medium-carbon steel, alloy steel, die steel, and cast iron. Not rated for coolant-through applications.

Installation Notes

This tap is installed by machinists and toolroom technicians using a tap wrench, tapping head, or CNC rigid tapping cycle. Ensure the workpiece is securely fixtured and the pilot hole is drilled to the correct tap drill diameter for 1/2-13 UNC before tapping. Apply appropriate tapping fluid or cutting oil for the workpiece material to extend tool life and improve thread finish. Do not reverse direction until the tap has completed the full thread depth in through-hole applications using spiral point taps.