Osg 2831201 Spiral Point Tap 5/16-24 Unf Plug Hss

Product Description

The OSG 2831201 is a spiral point plug tap designed for cutting internal threads in through-hole applications. Built from vanadium high-speed steel (HSS-E) with a steam oxide coating, it is engineered for durability and chip evacuation in production threading work. The plug chamfer distributes cutting load across the first several threads, making it suitable for machine tapping in CNC and manual setups alike. At 2.72 inches overall length with a 1-1/8 inch thread length and H3 thread limit, it produces 5/16-24 UNF Class 3B threads with consistent tolerances. Machinists, tool-and-die makers, and maintenance technicians working in light manufacturing and repair applications reach for this tap when threading ferrous and non-ferrous materials.

The 2831201 is suited for through-hole tapping across a wide range of workpiece materials, including aluminum, low-carbon steel, medium-carbon steel, high-carbon steel, alloy steel, die steel, stainless steel, and cast iron. The spiral point geometry pushes chips ahead of the tap and out through the exit side of the hole, reducing chip packing and tool breakage in CNC tapping centers and drill press setups. It is a standard production-grade tool for job shops, maintenance facilities, and manufacturing lines requiring reliable 5/16-24 UNF thread formation.

Key Features

• 5/16-24 UNF thread form with Class 3B fit and H3 thread limit for tight-tolerance internal threads
• Spiral point design pushes chips forward through the hole, preventing recutting and clogging
• Plug chamfer distributes cutting force gradually, reducing tap breakage at entry
• Vanadium high-speed steel (HSS-E) construction provides increased wear resistance over standard HSS
• Steam oxide coating improves lubricity and reduces galling, especially in ferrous materials
• Right-hand cut, 3 flutes, non-coolant-through design suitable for standard tapping fluid or cutting oil

Compatibility

Designed for use in any machine or hand-tapping setup requiring 5/16-24 UNF internal threads. Compatible with standard tap holders accepting a 0.318 inch shank diameter. Suitable for tapping aluminum, stainless steel, alloy steel, die steel, cast iron, and low-, medium-, and high-carbon steel workpieces.

Installation Notes

Install this tap in a rigid or floating tap holder appropriate for the machine being used. Ensure the workpiece is securely fixtured and the tap is aligned axially with the drilled hole before engaging. Apply cutting oil or tapping fluid appropriate for the workpiece material to reduce heat and extend tool life. Power down or disengage the spindle before removing or inspecting the tap after use.