Osg 1759101 Spiral Point Tap 4-40 Unc Plug 2 Flute

Product Description

The OSG 1759101 is a spiral point tap designed for cutting 4-40 UNC internal threads in a wide range of demanding materials. Built from powdered metal and finished with a steam oxide coating, this plug-chamfer tap drives chips forward ahead of the cutting zone, making it well suited for through-hole tapping applications. The H3 thread limit provides controlled tolerance for consistent fit across production runs. With an overall length of 1.874 inches and a 2-flute configuration, it delivers clean thread formation in tight work envelopes. Licensed machinists, tool-and-die makers, and maintenance technicians are the primary users of this tap.

This tap is rated for use in hardened steel, stainless steel, high-nickel alloy, titanium, alloy steel, and die steel. The spiral point geometry pushes chips forward rather than packing them into the flutes, which reduces the risk of tap breakage during through-hole operations. The plug chamfer provides a gradual thread lead-in, making it appropriate for general-purpose through-hole threading in production and repair environments alike.

Key Features

• Spiral point geometry pushes chips forward, reducing clogging in through-hole applications
• Steam oxide coating improves lubricity and corrosion resistance during cutting
• Powdered metal construction provides increased wear resistance compared to standard HSS
• H3 thread limit delivers consistent, controlled tolerance for 4-40 UNC threads
• Plug chamfer offers gradual thread engagement for smooth lead-in
• Right-hand thread direction for standard tapping operations

Compatibility

Designed for through-hole tapping of 4-40 UNC threads in hardened steel, stainless steel, high-nickel alloy, titanium, alloy steel, and die steel. Coolant-through is not supported.

Installation Notes

This tap is installed by machinists or maintenance technicians using a tap handle, tapping arm, or CNC tapping head. Ensure the workpiece is securely fixtured and the correct tap drill size for 4-40 UNC is used before threading. Apply appropriate cutting fluid for the workpiece material to extend tool life and improve thread quality. Inspect the tap for wear or chipping before each use, as small-diameter taps are susceptible to breakage under side load or misalignment.