Cleveland C58445 Spiral Flute Tap 5/16-18 Unc Bottoming Hss

Product Description

The CLEVELAND C58445 is a spiral flute bottoming tap designed for threading blind holes in a range of materials including aluminum, non-ferrous metals, and steel. It carries a 5/16-18 UNC thread form with a 3-flute, right-hand spiral configuration and a 52-degree helix angle that efficiently evacuates chips up and out of the hole during cutting. The bottoming chamfer allows threading close to the bottom of a blind hole, making it well suited for applications where thread depth is critical. Manufactured from high speed steel with an oxide finish, the C58445 delivers consistent performance in production and maintenance threading work. It fits a 2B class of fit and carries an H3 thread limit for controlled tolerance.

This tap is intended for blind hole threading operations in materials classified as aluminum, non-ferrous metals, and steel. The fast flute style and 52-degree helix angle promote chip flow in short-chipping and stringy materials alike. It is commonly used in machine shop production, maintenance repair, and field fabrication settings. The 5/16-18 UNC thread size is one of the most common fastener standards in North American equipment, making this tap a staple tool for machinists, millwrights, and general metalworkers. The bottoming chamfer type makes it appropriate where full thread depth to the bottom of a blind hole is required.

Key Features

• Bottoming chamfer for threading close to the bottom of blind holes
• 52-degree helix angle promotes fast, efficient chip evacuation
• 3-flute spiral design suited for aluminum, non-ferrous metals, and steel
• High speed steel construction for durability in production threading
• Oxide finish for mild corrosion resistance and reduced friction
• H3 thread limit with 2B class of fit for consistent, controlled tolerance

Compatibility

Designed for use in any standard tap holder or tapping head accepting a 0.318-inch shank diameter. Suitable for 5/16-18 UNC blind hole threading applications in aluminum, non-ferrous metals, and steel workpieces.

Installation Notes

Machinists and metalworkers should secure the tap in a properly aligned tap holder or machine tapping head before use to prevent tap breakage from misalignment. Always ensure the workpiece is clamped rigidly and that cutting fluid appropriate for the workpiece material is applied. Power down or de-energize any machine tool before changing tooling. Do not force the tap against the bottom of a blind hole beyond its designed thread length capacity.