Osg 2511401 Spiral Point Tap 4-40 Unc 2 Flute Plug Hss

Product Description

The OSG 2511401 is a spiral point tap designed for cutting 4-40 UNC internal threads in a wide range of ferrous and non-ferrous materials. It features a plug chamfer geometry and a 2-flute spiral point design that pushes chips ahead of the cut, keeping the flutes clear during through-hole tapping operations. Manufactured from vanadium high-speed steel (HSS-E) with a steam oxide coating, this tap offers improved lubricity and corrosion resistance compared to uncoated tooling. The H2 thread limit holds tight tolerances consistent with a 2B class of fit. Overall length is 2.25 inches with a thread length of 0.295 inches. Licensed machinists and maintenance technicians use this tap in CNC, turret, and hand-tapping applications.

This tap is suited for threading through-holes in materials including aluminum, low-carbon steel, medium-carbon steel, high-carbon steel, alloy steel, die steel, stainless steel, cast iron, and hardened steel. The 4-40 UNC thread form is common in light-duty fastener applications such as electronic enclosures, instrument panels, and precision mechanical assemblies. The plug chamfer makes it appropriate for through-hole work where the tap can run fully through the workpiece. Right-hand thread direction is standard for conventional CNC and manual tapping setups.

Key Features

• Spiral point geometry pushes chips forward, reducing re-cutting in through-hole applications
• Vanadium high-speed steel (HSS-E) construction provides increased wear resistance over standard M2 HSS
• Steam oxide coating improves lubricity and helps resist corrosion during storage and use
• H2 thread limit maintains 2B class of fit tolerance for consistent thread quality
• Plug chamfer with 2 flutes allows controlled entry and chip evacuation
• Right-hand cut, no coolant-through requirement — compatible with standard tapping fluids and cutting oils

Compatibility

Designed as a direct-use spiral point tap for 4-40 UNC through-hole threading in standard tapping chucks, tap holders, and floating tap collets compatible with Series 250 OSG tooling geometry.

Installation Notes

This tap should be installed in a tapping chuck or floating holder that provides axial float to prevent thread stripping. Secure the workpiece firmly before tapping and apply an appropriate cutting fluid or tapping compound for the material being threaded. Use the correct tap wrench or CNC spindle speed for the material and tap size — excessive speed increases the risk of tap breakage in small-diameter taps. Follow shop or facility safety protocols for rotating tooling and secure all loose material before operation.