Osg 1738701 Spiral Point Tap 1/2-13 Unc 3 Flute Plug

Product Description

The OSG 1738701 is a spiral point plug tap designed for threading 1/2-13 UNC internal threads in a wide range of steel materials. It features a 3-flute, plug chamfer geometry that pushes chips forward through the cut, making it well suited for through-hole threading applications. The tap is manufactured from vanadium high-speed steel (HSS-E), which provides improved toughness and wear resistance over standard M2 HSS. A steam oxide coating reduces friction and helps resist built-up edge during cutting. Thread limit is H5, and the class of fit is 2B, meeting standard tolerance requirements for most industrial fastener applications. Licensed machinists, toolroom technicians, and maintenance professionals are the primary users.

This tap is intended for right-hand threading in through-hole applications in materials including low-carbon steel, medium-carbon steel, hardened steel, and stainless steel. The plug chamfer entry requires a clean hole of correct pre-tap diameter before use. It is appropriate for use in manual tapping, CNC machining centers, and drill press setups where coolant-through tooling is not required. Series 300 designation indicates OSG standard production geometry.

Key Features

• Spiral point (gun tap) geometry pushes chips ahead of the tap for through-hole threading
• Vanadium high-speed steel (HSS-E) construction for improved toughness and extended tool life
• Steam oxide coating reduces friction and minimizes galling in steel materials
• Plug chamfer entry for gradual thread engagement in through-holes
• H5 thread limit holds 2B class of fit tolerances for standard inch fastener threads
• No coolant-through requirement - suitable for standard machine and hand tapping setups

Compatibility

Designed for threading 1/2-13 UNC right-hand internal threads in low-carbon steel, medium-carbon steel, hardened steel, and stainless steel workpieces. Not rated for coolant-through spindles.

Installation Notes

Install and remove tooling only with the machine spindle fully stopped and locked out per applicable safety procedures. Verify the pre-tap hole diameter matches the correct tap drill size for 1/2-13 UNC before tapping. Use an appropriate cutting fluid for the workpiece material - sulfurized oil is common for carbon steel, while stainless steel typically requires a higher-lubricity compound. Inspect the tap for chipping or wear before each use; a damaged tap can seize and break in the workpiece.