Osg 1729401 Spiral Point Tap 3/8-24 Unf Plug 2B Hss

Product Description

The OSG 1729401 is a spiral point plug tap designed for cutting right-hand internal threads in 3/8-24 UNF applications. Manufactured from Vanadium High Speed Steel (HSS-E) with a steam oxide coating, this tap is built for use in ferrous materials where heat and wear resistance matter. The plug chamfer — typically 3 to 5 threads — distributes cutting load at thread entry, making it suitable for through-hole tapping operations. With an H7 thread limit and a 2B class of fit, the 1729401 produces threads within tight tolerance ranges required for standard fastener assemblies. Machinists and maintenance techs install this tap in hand-tapping and machine-tapping setups alike.

This tap is suited for through-hole threading in hardened steel, low-carbon steel, medium-carbon steel, and stainless steel. The 3-flute design and spiral point geometry push chips forward ahead of the tap, clearing the cut zone and reducing chip packing in production and maintenance environments. At 2.937 inches overall length with a 0.381-inch shank diameter, it fits standard tap holders and tapping chucks used in drill press, CNC, and hand-tapping applications. The oxide coating provides a base level of lubricity and corrosion resistance for general-purpose use.

Key Features

• 3/8-24 UNF thread form with H7 thread limit and 2B class of fit for standard tolerance assemblies
• Vanadium High Speed Steel (HSS-E) construction for improved wear resistance over standard HSS
• Steam oxide coating reduces friction and provides mild corrosion protection
• Spiral point geometry pushes chips forward — optimized for through-hole tapping
• Plug chamfer (3-5 thread lead) balances cutting load at thread entry
• Right-hand cut, 3 flutes, no coolant-through — suited for general shop and maintenance use

Compatibility

Designed for through-hole tapping of 3/8-24 UNF threads in hardened steel, low-carbon steel, medium-carbon steel, and stainless steel workpieces. Compatible with standard tap holders and tapping attachments accepting a 0.381-inch shank diameter.

Installation Notes

Secure the workpiece and ensure the tap is properly aligned with the drilled hole before beginning the threading operation. Use an appropriate cutting fluid or tapping compound when threading stainless steel or hardened steel to reduce heat and extend tap life. For machine tapping, verify spindle speed is appropriate for the material and tap size per standard feeds-and-speeds guidelines. Inspect the tap for wear or chipping before each use — a damaged tap can seize in the workpiece and cause part damage.