Osg 1732001 Spiral Flute Tap 4-40 Unc Vanadium Hss

Product Description

The OSG 1732001 is a spiral flute tap designed for cutting internal 4-40 UNC threads in a range of steel materials. Built from vanadium high-speed steel with a steam oxide coating, it delivers consistent thread quality and extended tool life in production and maintenance applications. The 45-degree right-hand helix flute design pulls chips up and out of the hole, making it well suited for blind-hole tapping. The modified bottoming chamfer allows threading close to the bottom of a hole. With an overall length of 1.875 inches and an H2 thread limit, this tap holds tight tolerances for both 2B and 3B class-of-fit requirements.

This tap is used in machine shop, maintenance, and light manufacturing environments where small-diameter, fine-thread fastener holes are required. It is appropriate for use in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel workpieces. The 4-40 UNC size is common in instrument panels, electronics enclosures, and precision assemblies. It is intended for use in tapping machines, CNC machining centers, or drill press setups with a proper tap holder.

Key Features

• 45-degree right-hand spiral flute geometry evacuates chips from blind holes during tapping
• Modified bottoming chamfer enables threading closer to the bottom of a blind hole
• Vanadium high-speed steel construction provides wear resistance in steel and stainless applications
• Steam oxide coating reduces friction and improves lubrication retention
• H2 thread limit holds 2B and 3B class-of-fit tolerances
• Right-hand thread direction, 3 flutes, 40 threads per inch

Compatibility

Designed for cutting 4-40 UNC internal threads in stainless steel, high-carbon steel, low-carbon steel, and medium-carbon steel. Compatible with standard tap holders and collet chucks sized for a 0.141-inch shank diameter.

Installation Notes

Installation should be performed by a qualified machinist or tool and die technician using a rigid or floating tap holder appropriate for the machine setup. Always use a cutting fluid or tapping oil rated for the workpiece material, especially when tapping stainless steel. Secure the workpiece firmly and ensure the tap is aligned perpendicular to the work surface before beginning the cut. Inspect the tap for wear or damage before each use and replace if thread quality degrades.