Osg 1754101 Spiral Flute Tap 4-40 Unc Modified Bottoming

Product Description

The OSG 1754101 is a spiral flute tap designed for threading 4-40 UNC holes in demanding materials. It features a modified bottoming chamfer, two right-hand spiral flutes with a 15-degree helix angle, and a steam oxide coating that reduces friction and extends tool life in production environments. The powdered metal construction provides consistent hardness and wear resistance across the cutting edges. With an overall length of 1.875 inches and a shank diameter of 0.141 inches, this tap is sized for small-diameter threading operations in machine shop, maintenance, and precision assembly applications. Thread limit is H3, suitable for standard tolerance fits on 4-40 UNC fasteners.

This tap is intended for threading alloy steel, stainless steel, hardened steel, titanium, and high-nickel alloy workpieces. The spiral flute geometry evacuates chips upward, making it well suited for blind-hole applications where chip packing is a concern. It is commonly used in CNC tapping, drill press, and tapping head setups across aerospace, automotive, and industrial maintenance operations requiring reliable small-thread production.

Key Features

• Modified bottoming chamfer allows threading close to the bottom of blind holes
• 15-degree right-hand spiral flute geometry promotes upward chip evacuation
• Steam oxide coating reduces friction and galling on difficult-to-machine alloys
• Powdered metal construction delivers uniform hardness for consistent thread quality
• H3 thread limit ensures proper tolerance fit for standard 4-40 UNC fastener applications
• No coolant-through requirement simplifies setup in standard machine environments

Compatibility

Designed for threading 4-40 UNC holes in alloy steel, stainless steel, hardened steel, titanium, and high-nickel alloy workpieces. Part of OSG Series 313.

Installation Notes

Install in a tapping chuck, CNC spindle, or manual tapping head rated for the shank diameter. Ensure the workpiece is securely fixtured and the spindle is aligned perpendicular to the hole before engaging the tap. Use an appropriate cutting fluid for the workpiece material to reduce heat buildup and extend tool life. Inspect the tap for chipping or wear before each use, as small-diameter taps are susceptible to breakage if run in worn or misaligned setups.