Osg 2531601 Spiral Point Tap 3/8-16 Unc Plug Hss

Product Description

The OSG 2531601 is a spiral point plug tap designed for cutting 3/8-16 UNC threads in through-hole applications. Manufactured from Vanadium High Speed Steel (HSS-E) with a steam oxide coating, it delivers consistent thread quality across a broad range of ferrous and non-ferrous materials. The spiral point geometry pushes chips forward ahead of the tap, preventing chip packing in the flute and allowing for clean, continuous threading. With a 3-flute, H2 thread limit design and 2B class of fit, this tap produces threads suitable for standard fastener engagement in production and maintenance environments. Overall length is 3.937 inches with a 0.752 inch thread length and a 0.381 inch shank diameter.

This tap is suited for threading through-holes in aluminum, low-carbon steel, medium-carbon steel, high-carbon steel, alloy steel, die steel, stainless steel, and cast iron. It is commonly used in machine shop production runs, maintenance and repair operations, and fabrication environments where right-hand UNC threads are required. The plug chamfer makes it appropriate for through-hole work where the tap can pass fully through the material. It is used in CNC machining centers, drill presses, and tapping machines where controlled feed rates are maintained.

Key Features

• Spiral point geometry pushes chips forward, ideal for through-hole tapping
• Vanadium HSS-E construction provides wear resistance across hard and abrasive materials
• Steam oxide coating reduces friction and improves lubrication retention
• H2 thread limit and 2B class of fit for standard-tolerance UNC thread production
• Plug chamfer with 3 flutes for smooth entry and consistent thread form
• Right-hand thread direction, compatible with standard tapping setups

Compatibility

Designed for cutting 3/8-16 UNC right-hand threads in through-hole applications across aluminum, hardened steel, stainless steel, high-carbon steel, low-carbon steel, medium-carbon steel, alloy steel, die steel, and cast iron workpieces.

Installation Notes

This tap should be installed by a machinist or tooling technician familiar with tapping operations. Always use the appropriate tapping fluid or cutting oil for the workpiece material, and ensure the tap is aligned perpendicular to the workpiece surface before engagement. For machine tapping, use a tapping attachment or floating holder to prevent tap breakage from misalignment or feed inconsistency. Inspect the tap for wear or chipping before each use and replace at the first sign of thread quality degradation.