Osg 1722008 Spiral Flute Tap 4-40 Unc Vanadium Hss

Product Description

The OSG 1722008 is a spiral flute tap designed for cutting 4-40 UNC internal threads in a range of ferrous materials. Built from vanadium high-speed steel and finished with a TiCN (titanium carbonitride) coating, this tap delivers improved wear resistance and lubricity compared to uncoated HSS tools. It features a modified bottoming chamfer for threading closer to the bottom of blind holes. With a 45-degree helix angle and three right-hand flutes, the tap efficiently evacuates chips upward out of the hole during the threading operation. Installed by machinists and precision fabricators, this tap is suited for production and maintenance work where thread quality and tool life in harder steels matter.

The OSG 1722008 is intended for threading operations in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel workpieces. Its modified bottoming chamfer makes it a practical choice for blind-hole applications where thread engagement close to the hole bottom is required. The 4-40 UNC thread form is common in small-fastener assemblies found in electronics enclosures, precision instruments, and light mechanical assemblies. This tap is suitable for both CNC tapping centers and manual tapping operations using a tap wrench or tapping arm.

Key Features

• 4-40 UNC thread form with 40 threads per inch for small-fastener applications
• Vanadium high-speed steel construction provides increased hardness and toughness over standard M2 HSS
• TiCN coating improves surface hardness and reduces friction against stainless and carbon steels
• 45-degree right-hand spiral flutes promote upward chip evacuation in blind holes
• Modified bottoming chamfer allows thread cutting close to the bottom of blind holes
• H3 thread limit for close-tolerance thread fits in production environments

Compatibility

Designed for cutting 4-40 UNC threads in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel. Part of the OSG EXOTAP VA3 series.

Installation Notes

This tap is installed by machinists and tool-and-die professionals using a tapping chuck, CNC rigid tap holder, or manual tap wrench. Always use the recommended tap drill size for 4-40 UNC threads and verify drill depth before tapping blind holes. Apply a suitable cutting fluid for the workpiece material, particularly when threading stainless steel, to reduce heat buildup and extend tool life. Do not reverse the tap under power without confirming the machine is set for rigid tapping or a floating holder is in use.