Osg 1651506208 Spiral Point Tap 5/16-32 Unef Plug 3B

Product Description

The OSG 1651506208 is a spiral point tap designed for cutting internal threads in a wide range of ferrous and non-ferrous metals. It produces a 5/16-32 UNEF right-hand thread to a 3B class of fit with an H3 thread limit, delivering consistent dimensional accuracy for precision threaded assemblies. The tap is manufactured from powdered metal and finished with an OSG V (VC-10) coating, which reduces friction and extends tool life across demanding materials. Overall length is 3.15 inches with a thread length of 0.653 inches and a shank diameter of 0.318 inches. Licensed machinists and tool-and-die professionals install this tap using a tap wrench, CNC tapping head, or drill press with tapping attachment.

This tap is suited for through-hole tapping applications in production and maintenance machining environments. The spiral point design pushes chips forward ahead of the tap, making it effective in through-holes where chip evacuation is straightforward. It is appropriate for use in alloy steel, aluminum, cast aluminum, cast iron, hardened steel, high-carbon steel, low-carbon steel, medium-carbon steel, stainless steel, and die steel. Both manual and machine tapping setups in job shop, OEM, and MRO contexts are typical application scenarios.

Key Features

• 5/16-32 UNEF thread form with 3B class of fit and H3 thread limit for precise tolerance control
• Powdered metal construction provides superior wear resistance compared to standard HSS
• OSG V (VC-10) coating reduces cutting friction and improves tool life in hard and abrasive materials
• Spiral point geometry pushes chips forward, optimized for through-hole tapping
• Plug chamfer with 3 flutes balances chip clearance and thread engagement on entry
• Right-hand thread direction, no coolant-through feature, non-interrupted thread form

Compatibility

Designed for through-hole tapping of 5/16-32 UNEF threads in alloy steel, aluminum, cast aluminum, cast iron, hardened steel, high-carbon steel, low-carbon steel, medium-carbon steel, stainless steel, and die steel workpieces.

Installation Notes

Installation should be performed by a qualified machinist following standard tapping practices. Ensure the workpiece is securely fixtured and the tap is properly aligned with the drilled pilot hole before engagement. Use a suitable tapping fluid or cutting oil appropriate to the workpiece material to promote chip evacuation and reduce heat buildup. Do not reverse the tap abruptly under load, as powdered metal tooling can fracture if subjected to sudden torque reversals without proper technique.