Cleveland C54514 Straight Flute Tap 5/16-18 Unc Hss

Product Description

The CLEVELAND C54514 is a 4-flute, straight-flute plug tap designed for cutting 5/16-18 UNC internal threads in both blind and through-hole applications. Manufactured from high speed steel with a bright/uncoated finish, this tap is built for general-purpose hand and machine tapping where cutting fluid is applied externally. The plug chamfer — typically 3 to 5 threads — provides a balance between starting ease and thread engagement, making it suitable for a wide range of production and maintenance threading tasks. The H11 thread limit indicates an oversize condition of 0.0050 inches, which is factored in for plated or close-tolerance thread requirements.

This tap is intended for use in metalworking and maintenance applications across manufacturing, mechanical contracting, and industrial service environments. It is rated for threading in alloy steel, aluminum, carbon steel, and free-machining stainless steel. The plug style is the most common tap used in general shop work, appropriate for both through-holes and blind holes with adequate chip clearance. Thread length runs 0.6900 inches, and overall length is 2-23/32 inches, making it compatible with standard tap holders and floating tap chucks used in drill press or CNC tapping operations.

Key Features

• 5/16-18 UNC thread form with plug chamfer for versatile blind and through-hole use
• 4 straight flutes for chip evacuation in ductile and non-ferrous materials
• High speed steel construction for general-purpose machine and hand tapping
• H11 thread limit with 0.0050 inch oversize for plating allowance or close-fit thread control
• Bright/uncoated finish — compatible with most cutting oils and tapping fluids
• Right-hand thread direction; no coolant-through requirement

Compatibility

Designed for cutting 5/16-18 UNC internal threads in alloy steel, aluminum, carbon steel, and free-machining stainless steel workpieces. Fits standard tap wrenches and machine tap holders accepting a 0.3180-inch shank diameter with a 3/8-inch square drive.

Installation Notes

This tap is installed by machinists, tool and die makers, and maintenance technicians using a tap wrench, tapping head, or CNC rigid tap cycle. Before tapping, ensure the correct drill size for 5/16-18 UNC threads is used and the workpiece is securely fixtured. Apply appropriate cutting fluid for the workpiece material throughout the tapping operation. Inspect the tap for wear or chipping before each use and never force a tap that has stalled in the hole.