Cleveland C57150 Spiral Point Tap 5/16-18 Unc 2 Flutes

Product Description

The CLEVELAND C57150 is a spiral point tap designed for through-hole threading in metalworking applications. It cuts a 5/16-18 UNC right-hand thread using a 2-flute, plug-chamfer geometry that pushes chips forward and out of the hole, keeping the flutes clear during operation. Built from high speed steel with a bright finish, the C57150 measures 2.719 inches overall length with an 11/16-inch thread length and an H2 thread limit for close, consistent tolerance control. This tap suits production and maintenance shops where clean, repeatable internal threads are required in through-hole work. It is sold individually.

The C57150 is suited for through-hole threading in alloy steel, carbon steel, and aluminum workpieces. The plug chamfer — typically 3 to 5 lead threads — makes it the standard choice for starting in a pre-drilled through hole where the tap can clear chips forward. The 2B class of fit is the most common tolerance class for general-purpose UNC fastener applications across both residential and commercial fabrication, maintenance, and repair environments.

Key Features

• Spiral point geometry pushes chips forward, preventing packing in through-hole operations
• High speed steel construction provides wear resistance across a range of ferrous and non-ferrous materials
• Plug chamfer for easy starting and through-hole threading
• H2 thread limit for precise tolerance control on 2B class of fit threads
• Bright finish — no coating — provides a baseline surface suitable for a wide range of cutting fluids
• Right-hand cut, 5/16-18 UNC thread standard

Compatibility

Designed for through-hole threading in alloy steel, aluminum, and carbon steel. Compatible with standard tap holders and chucks accepting a 0.318-inch shank diameter.

Installation Notes

This tap is installed by machinists and maintenance mechanics using a standard tap wrench, drill press, or CNC tapping attachment. Always ensure the workpiece is securely fixtured and that the tap is properly aligned with the drilled hole before engagement to avoid tap breakage. Use an appropriate cutting fluid for the workpiece material — sulfurized oil for steel, aluminum-safe fluid for aluminum. Do not use this tap for blind-hole threading without selecting a bottoming or semi-bottoming style tap.