Osg 1728301 Spiral Point Tap 12-28 Unf 3 Flutes

Product Description

The OSG 1728301 is a spiral point plug tap designed for cutting right-hand internal threads in a 12-28 UNF thread form. It features 3 flutes and a plug chamfer, making it suited for through-hole tapping applications where chips are pushed forward ahead of the cutting edge. Manufactured from vanadium high speed steel (HSS-E) with a steam oxide coating, the 1728301 offers improved lubricity and corrosion resistance during tapping operations. The H3 thread limit and 2B/3B class of fit make it compatible with standard fastener fit requirements in precision assembly and maintenance work.

This tap is used in general metalworking and maintenance applications across manufacturing, fabrication, and repair environments. Its material application range includes hardened steel, low-carbon steel, medium-carbon steel, and stainless steel. The plug chamfer style makes it best suited for through-hole tapping rather than blind holes. It is typically installed by machinists, tool and die workers, and maintenance technicians using a tap wrench, tapping head, or CNC spindle.

Key Features

• 12-28 UNF thread form with H3 thread limit for consistent fit tolerance
• 3-flute spiral point design pushes chips forward, ideal for through-hole applications
• Vanadium high speed steel (HSS-E) construction for improved toughness and wear resistance
• Steam oxide coating reduces friction and improves chip flow
• Plug chamfer for standard through-hole tapping entry
• Right-hand thread direction, no coolant-through, non-interrupted thread design

Compatibility

Designed for tapping 12-28 UNF threads in hardened steel, low-carbon steel, medium-carbon steel, and stainless steel workpieces. Suitable for use in tap wrenches, tapping heads, or CNC spindle holders that accept the 0.2200-inch shank diameter of OSG Series 300 taps.

Installation Notes

Power down or de-energize any CNC machine or tapping equipment before installing or changing the tap. Secure the tap in a properly sized chuck or tap holder to prevent slippage and thread damage. Apply appropriate cutting fluid for the workpiece material, particularly when tapping stainless steel. Inspect the tap for wear or chipping before each use to maintain thread quality and avoid tool breakage.