Osg 1728201 Spiral Point Tap 12-24 Unc Plug H3 Hss

Product Description

The OSG 1728201 is a spiral point plug tap designed for cutting 12-24 UNC right-hand threads in through-hole applications. Manufactured from vanadium high-speed steel (HSS-E) with a steam oxide coating, this tap offers improved lubricity and corrosion resistance during the tapping operation. It features 3 flutes, an H3 thread limit, and a plug chamfer that allows for gradual thread engagement. The overall length is 2.374 inches with a thread length of 0.58 inches (15/16 inches) and a shank diameter of 0.22 inches. The spiral point geometry pushes chips forward ahead of the tap, making it suited for machine tapping in through holes rather than blind holes.

This tap is suited for threading through holes in a range of ferrous materials including low-carbon steel, medium-carbon steel, hardened steel, and stainless steel. It fits standard production and job-shop CNC machining, drill press, and tapping machine setups where 12-24 UNC threads are required. The 2B and 3B class of fit coverage makes it versatile for both standard commercial and close-tolerance threaded fastener applications. The Series 300 designation places it within OSG's general-purpose tapping line targeting industrial machining environments.

Key Features

• Spiral point geometry pushes chips forward, optimized for through-hole tapping
• Vanadium high-speed steel (HSS-E) construction for increased wear resistance over standard M2 HSS
• Steam oxide coating reduces friction and provides light corrosion protection
• H3 thread limit with plug chamfer for gradual thread lead-in and accurate thread sizing
• Right-hand thread direction, 3 flutes, no coolant-through requirement
• Covers 2B and 3B class of fit for versatile fastener thread applications

Compatibility

Designed for cutting 12-24 UNC right-hand internal threads in low-carbon steel, medium-carbon steel, hardened steel, and stainless steel workpieces. Suited for through-hole applications on CNC machining centers, drill presses, and dedicated tapping machines using standard tap holders.

Installation Notes

This tap should be installed by a qualified machinist or tooling technician using a tap holder or collet sized to the 0.22-inch shank diameter. Ensure the workpiece is securely clamped and the spindle is aligned perpendicular to the hole before beginning the tapping cycle. Apply an appropriate cutting fluid for the workpiece material to extend tool life, particularly when tapping stainless steel. Do not exceed the recommended surface footage for HSS tooling, and reverse the spindle to break chips if manual tapping is performed.