Osg 1700401 Spiral Point Tap 1/4-28 Unf Plug 3 Flute

Product Description

The OSG 1700401 is a spiral point tap designed for cutting 1/4-28 UNF right-hand threads in through-hole applications. Built from powdered metal and finished with a steam oxide coating, this tap is engineered for use in harder, more demanding materials where standard high-speed steel falls short. The plug chamfer provides gradual thread engagement over the first few threads, making it suitable for through-holes where the tap can push chips forward ahead of the cutting action. With 3 flutes and an H5 thread limit, it delivers controlled tolerances consistent with precision fastener applications. Licensed tradespeople and machinists in manufacturing, maintenance, and repair environments rely on this tap series for consistent thread quality across production and one-off jobs alike.

The OSG 1700401 is intended for threading through-holes in a range of ferrous and specialty materials. The steam oxide finish provides mild lubricity and corrosion resistance during cutting operations. Rated material applications include hardened steel, stainless steel, high-nickel alloy, titanium, alloy steel, and die steel. Its compact shank diameter of 0.255 inches and overall length of 2.5 inches make it compatible with standard tap holders and machine spindles used in vertical mills, drill presses, and CNC machining centers. This is a non-coolant-through design intended for use with external cutting fluid application.

Key Features

• 1/4-28 UNF thread form with right-hand cutting direction
• Plug chamfer for through-hole applications — pushes chips forward ahead of the tap
• Powdered metal construction with steam oxide coating for extended wear life in tough materials
• H5 thread limit for close-tolerance fits in precision assemblies
• 3-flute geometry balances chip clearance with cutting rigidity
• Rated for hardened steel, stainless steel, high-nickel alloy, titanium, alloy steel, and die steel

Compatibility

Designed for through-hole tapping in materials including hardened steel, stainless steel, high-nickel alloy, titanium, alloy steel, and die steel. Compatible with standard 1/4-inch tap holders, T-handle wrenches, and machine spindle adapters sized for a 0.255-inch shank diameter.

Installation Notes

This tap is installed by a machinist or maintenance technician using a tap wrench, tapping head, or rigid machine spindle. Secure the workpiece fully before tapping and ensure the hole is drilled to the correct tap drill size for 1/4-28 UNF before starting. Apply cutting fluid appropriate for the workpiece material throughout the operation. Do not force the tap — back off periodically to break chips and prevent binding, particularly in stainless steel and high-nickel alloys.