Cleveland C57149 Spiral Point Tap 5/16-18 Unc 2 Flutes

Product Description

The CLEVELAND C57149 is a spiral point tap designed for through-hole threading in metal workpieces. It cuts a 5/16-18 UNC thread profile using a two-flute, plug chamfer geometry that drives chips forward ahead of the cutting zone, making it well suited for threading through-holes without chip packing. The tap is manufactured from high speed steel (HSS) with a bright finish and conforms to an H1 thread limit and a Class 2B fit tolerance. The overall length is 2.719 inches with a thread length of 0.69 inches. Licensed machinists, tool-and-die makers, and maintenance mechanics typically select this tap for production and repair threading operations.

This tap is intended for through-hole threading applications in alloy steel, carbon steel, and aluminum workpieces. The plug chamfer distributes the cutting load across several leading threads, making it appropriate for starting a tap in a pre-drilled through-hole without a guide fixture. It fits standard tapping chucks, tap wrenches, and CNC tapping spindles that accept the 0.318-inch shank diameter. The Series 1011 designation identifies it within the CLEVELAND catalog line of general-purpose HSS spiral point taps.

Key Features

• Spiral point geometry pushes chips forward through the hole, reducing clogging in through-hole applications
• Plug chamfer distributes cutting load across leading threads for controlled entry
• High speed steel construction provides wear resistance across alloy steel, carbon steel, and aluminum
• H1 thread limit and Class 2B fit deliver standard tolerance threading for general fastener assembly
• Bright finish with no coating keeps regrinding simple and cost-effective
• Coolant-through design is not required, compatible with flood or mist coolant applied externally

Compatibility

Designed for through-hole threading of alloy steel, aluminum, and carbon steel workpieces requiring a 5/16-18 UNC Class 2B thread. Fits standard tap holders and tapping chucks accepting a 0.318-inch shank diameter.

Installation Notes

This tap is installed by machinists and maintenance mechanics using a tap wrench, tapping fixture, or CNC tapping spindle. Always use the correct tap drill size for a 5/16-18 UNC thread and ensure the workpiece is securely fixtured before beginning the threading operation. Apply cutting fluid appropriate for the workpiece material to extend tap life and improve thread finish. Remove the tap periodically to clear chips when threading deep or interrupted through-holes.