Osg 1759108 Spiral Point Tap 4-40 Unc Plug Ticn

Product Description

The OSG 1759108 is a spiral point tap designed for threading 4-40 UNC holes in demanding materials. Built from powdered metal and coated with TiCN (Titanium Carbonitride), this tap delivers improved wear resistance and heat tolerance compared to standard high-speed steel options. The plug chamfer configuration, 2-flute design, and H3 thread limit make it well-suited for through-hole tapping operations where chip pushing ahead of the cutting action is acceptable. Overall length is 1.874 inches with a 0.141-inch shank diameter. Thread length is 9/16 inches. Right-hand cut only. Installed by machinists and toolroom technicians in production and maintenance environments.

This tap is used for cutting 4-40 UNC internal threads in through-hole applications across a range of ferrous and non-ferrous materials. The TiCN coating and powdered metal substrate extend tool life when working in hardened steel, stainless steel, high-nickel alloy, titanium, alloy steel, and die steel. It is a practical choice for aerospace, tool-and-die, and precision manufacturing operations where thread quality and tool longevity are critical. The H3 thread limit provides the oversize tolerance needed when tapping harder or coated materials that cause thread springback.

Key Features

• 4-40 UNC thread form with H3 thread limit for use in harder and coated materials
• TiCN coating improves surface hardness and reduces friction for extended tool life
• Powdered metal construction provides consistent grain structure and toughness
• Plug chamfer promotes chip pushing in through-hole applications
• 2-flute design suited for small-diameter tapping with limited chip clearance
• Right-hand cut, no coolant-through, non-interrupted thread profile

Compatibility

Designed for use in through-hole tapping of hardened steel, stainless steel, high-nickel alloy, titanium, alloy steel, and die steel workpieces requiring 4-40 UNC internal threads.

Installation Notes

This tap is installed by machinists using a tapping head, CNC machine, or hand tap wrench aligned perpendicular to the workpiece. Ensure the drilled hole diameter is correct for 4-40 UNC thread engagement before tapping. Apply an appropriate cutting fluid for the workpiece material, especially when tapping stainless steel or high-nickel alloys. Do not reverse the tap under power without confirming the drive is set for back-out; breaking a small-diameter tap in a workpiece is difficult to recover.