Osg 2941001 Spiral Flute Tap 5/16-18 Unc Vanadium Hss

Product Description

The OSG 2941001 is a spiral flute tap designed for threading 5/16-18 UNC right-hand threads in a variety of ferrous materials. It features 3 right-hand spiral flutes with a 45-degree helix angle, which evacuates chips upward out of the hole during tapping - a critical advantage in blind-hole applications. The tap is ground from 3% vanadium high-speed steel (HSS) and finished with a steam oxide coating to reduce friction and improve lubricity during cutting. The modified bottoming chamfer allows threading close to the bottom of blind holes. Overall length is 2-23/32 inches with a thread limit designation of H7, indicating a slight oversize tolerance suitable for plated threads.

This tap is suited for use in job shops, maintenance and repair operations, and production environments where blind-hole tapping of ferrous materials is required. Compatible materials include alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel. The 45-degree helix angle makes it particularly effective in materials that produce long, stringy chips. It is typically used in drill press, CNC machining center, and manual tapping operations where a tapping driver or synchronized spindle is available.

Key Features

• 5/16-18 UNC thread form with right-hand direction and H7 thread limit tolerance
• 45-degree helix angle promotes upward chip evacuation in blind-hole tapping
• Modified bottoming chamfer for threading close to the bottom of blind holes
• 3% vanadium HSS construction for improved wear resistance over standard M2 HSS
• Steam oxide coating reduces friction and galling during thread cutting
• Rated for alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel

Compatibility

The OSG 2941001 is part of the OSG Series 290 spiral flute tap line and is designed for tapping 5/16-18 UNC blind holes in alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel workpieces.

Installation Notes

This tap is intended for installation by machinists and tool and die technicians using a tapping driver, tapping head, or CNC rigid-tapping spindle. Ensure the tap is properly aligned with the drilled hole before engagement to prevent cross-threading or tap breakage. Use a suitable cutting fluid or tapping compound appropriate for the workpiece material. Never reverse a spiral flute tap under power without confirming the machine supports synchronized reversal.