Osg 1734801 Spiral Point Tap 4-40 Unc 2 Flute Plug

Product Description

The OSG 1734801 is a spiral point plug tap designed for cutting 4-40 UNC internal threads in a range of ferrous materials. Manufactured from vanadium high speed steel (HSS-E) with a steam oxide coating, this tap offers improved lubricity and corrosion resistance compared to uncoated tooling. It features 2 flutes with a plug chamfer, an H3 thread limit for controlled tolerance fits, and a right-hand thread direction. Overall length is 1.874 inches with a thread length of 0.33 inches and a shank diameter of 0.141 inches. This tool is installed by machinists, maintenance technicians, and tool-and-die professionals working on precision threaded assemblies.

The OSG 1734801 is suited for tapping 4-40 UNC threads in production and maintenance environments. Its spiral point geometry pushes chips forward ahead of the cutting action, making it well-suited for through-hole tapping operations. Rated material applications include hardened steel, low-carbon steel, medium-carbon steel, and stainless steel. The plug chamfer provides a gradual lead-in for starting threads in pre-drilled holes, balancing speed and tool life across moderate-volume runs.

Key Features

• 4-40 UNC thread form with H3 tolerance limit for controlled fit
• Spiral point geometry advances chips forward - optimized for through-hole applications
• Vanadium high speed steel (HSS-E) construction for improved wear resistance over standard HSS
• Steam oxide coating reduces friction and improves lubricity during cutting
• Plug chamfer for gradual thread engagement and smooth starts
• Right-hand thread direction, no coolant-through requirement

Compatibility

Rated for use in hardened steel, low-carbon steel, medium-carbon steel, and stainless steel. Designed as a standard replacement or production tap for any application requiring 4-40 UNC right-hand internal threads.

Installation Notes

This tap is installed by machinists or maintenance technicians using a tap wrench, tapping head, or CNC tapping cycle. Ensure the workpiece is securely fixtured and the pilot hole is drilled to the correct 4-40 UNC tap drill diameter before use. Apply appropriate cutting fluid for the workpiece material, particularly when tapping stainless steel. Inspect the tap for wear or chipping before each use and replace immediately if damage is observed to avoid thread damage or breakage in the workpiece.