Cleveland C55218 Hand Tap 1/4-28 Bottoming Tin Hss Unf

Product Description

The CLEVELAND C55218 is a 1/4-28 bottoming hand tap designed for cutting internal threads in ferrous and non-ferrous materials. Built from high speed steel with a titanium nitride (TiN) coating, it delivers extended tool life and reduced friction across demanding production and maintenance threading operations. The four-flute straight flute geometry provides clean chip evacuation and stable cutting action. At 2.5 inches overall length with a 1-inch thread length, the C55218 is sized for compact threading reaches. The bottoming chamfer style allows threading nearly to the full depth of a blind hole, making it the preferred choice when thread engagement at the bottom of a bore is required.

This tap is suited for both blind hole and through-hole threading applications in a shop or field environment. It conforms to UNF thread standards with a 3B class of fit and H3 thread limit, making it appropriate for standard tolerance internal threads used in precision assemblies. Compatible material applications include alloy steel, carbon steel, aluminum, and free-machining stainless steel. It is part of the Cleveland Series 1003TN and is commonly used by machinists, maintenance technicians, and tool and die professionals working on threaded fastener repairs or new part fabrication.

Key Features

• Bottoming chamfer allows threading close to the bottom of blind holes
• TiN coating reduces friction and increases wear resistance for longer tool life
• High speed steel construction handles alloy steel, carbon steel, aluminum, and free-machining stainless steel
• 4-flute straight flute design provides stable cutting and consistent chip clearance
• H3 thread limit and 3B class of fit meet standard UNF tolerance requirements
• Right-hand thread direction for conventional tap wrench or machine use

Compatibility

Designed for blind hole and through-hole threading in alloy steel, carbon steel, aluminum, and free-machining stainless steel workpieces requiring a 1/4-28 UNF internal thread with a 3B class of fit.

Installation Notes

This tap is installed by machinists using a tap wrench, T-handle, or tapping machine set to the appropriate speed for the workpiece material. Ensure the pilot hole is drilled to the correct tap drill size for 1/4-28 UNF threads before tapping. Apply cutting fluid appropriate for the workpiece material to reduce heat and improve thread finish. Do not force the tap if resistance increases suddenly, as this can cause breakage in the hole.