Osg 2928008 Spiral Flute Tap 1/4-20 Unc Ticn Vanadium Hss

Product Description

The OSG 2928008 is a spiral flute tap designed for cutting internal 1/4-20 UNC right-hand threads in a range of ferrous and alloy materials. Built from vanadium high-speed steel and finished with a TiCN (titanium carbonitride) coating, this tap delivers extended tool life and reduced friction in demanding tapping applications. The modified bottoming chamfer allows threading closer to the bottom of blind holes compared to standard taper or plug styles. With a 45-degree helix angle and 3 right-hand flutes, it efficiently evacuates chips upward and out of the hole. The H2 thread limit provides consistent tolerance control suited to standard UNC thread fits. Licensed machinists, toolroom technicians, and maintenance tradespeople are the typical installers.

This tap is well suited for production and maintenance tapping in alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel workpieces. The Series 290 spiral flute design makes it particularly effective in blind-hole applications where chip packing is a concern. It is sold and packaged as a single unit, making it a straightforward replacement or addition to a tap set for job-site or shop use.

Key Features

• TiCN coating reduces friction and increases surface hardness for longer tool life in hard and abrasive materials
• Vanadium high-speed steel construction provides toughness and wear resistance across a broad range of workpiece materials
• 45-degree helix angle promotes efficient upward chip evacuation in blind holes
• Modified bottoming chamfer allows threading closer to the bottom of blind holes than plug or taper styles
• H2 thread limit ensures consistent tolerance control for standard UNC thread fits
• No coolant-through requirement simplifies use in conventional tapping setups

Compatibility

Designed as an OEM-style spiral flute tap for 1/4-20 UNC threading operations in alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel. Compatible with standard tap holders and tapping heads accepting a 0.381-inch shank diameter.

Installation Notes

This tap should be installed by qualified machinists or toolroom technicians using a properly sized tap holder or tapping head. Always ensure the workpiece is securely fixtured and the spindle is aligned before beginning the tapping cycle. Apply an appropriate cutting fluid or tapping compound for the specific workpiece material to protect the cutting edges and extend tool life. Inspect the tap for wear or chipping before each use and replace if cutting edge integrity is compromised.