Osg 1740705 Spiral Point Tap 1/4-28 Unf Tin Coated Hss

Product Description

The OSG 1740705 is a spiral point tap designed for threading 1/4-28 UNF internal threads in a wide range of metallic materials. Built from Vanadium High Speed Steel (HSS-E) with a Titanium Nitride (TiN) coating, this plug-chamfer tap offers improved wear resistance and reduced friction during cutting. It features 3 flutes, an H3 thread limit, and a 3B class of fit, making it well suited for precision threading applications where tight tolerances are required. With an overall length of 2.5 inches and a thread length of 0.594 inches, it fits standard tap holders and machine spindles used in machining and fabrication shops.

This tap is intended for use in through-hole threading operations across a broad range of materials including aluminum, low-carbon steel, medium-carbon steel, high-carbon steel, alloy steel, die steel, stainless steel, and cast iron. The spiral point geometry pushes chips forward ahead of the tap, making it especially effective in through-hole applications on CNC machining centers, drill presses, and manual tapping machines. It is used by machinists, toolmakers, and maintenance technicians in production and repair environments.

Key Features

• 1/4-28 UNF thread form with H3 thread limit for consistent tolerance control
• Vanadium High Speed Steel (HSS-E) construction for elevated hardness and toughness
• TiN coating reduces friction and extends tool life in ferrous and non-ferrous materials
• Plug chamfer style for easy thread starting in through-hole applications
• 3-flute spiral point design pushes chips forward, preventing chip packing
• Right-hand thread direction, 3B class of fit for standard UNF fastener compatibility

Compatibility

Designed as a standard replacement or production tap for 1/4-28 UNF through-hole threading applications in materials including aluminum, stainless steel, alloy steel, die steel, cast iron, and low-, medium-, and high-carbon steel.

Installation Notes

Install in a tap holder, collet chuck, or rigid tapping head rated for the shank diameter of 0.255 inches. Always ensure the workpiece is securely fixtured before beginning the tapping cycle. Apply appropriate cutting fluid for the material being tapped to maximize tool life and thread quality. Power down or de-energize any machine spindle before changing or inspecting the tap.