Cleveland C57137 Spiral Point Tap 1/4-28 Unf 2 Flute Hss

Product Description

The CLEVELAND C57137 is a spiral point tap designed for through-hole threading applications in metalworking and machining environments. Built from high speed steel with a bright finish, this plug chamfer tap threads 1/4-28 UNF right-hand internal threads with consistent accuracy. The two-flute spiral point geometry pushes chips forward ahead of the cutting action, keeping the flutes clear and reducing the risk of chip-related breakage in through-hole work. Overall length is 2.5 inches, with a thread length of 0.63 inches. The H2 thread limit ensures dimensional control within standard 2B class of fit tolerances. Installed by machinists and toolroom technicians in production and maintenance settings.

The C57137 is suited for through-hole threading in alloy steel, carbon steel, and aluminum workpieces. The 1/4-28 UNF thread specification makes it applicable in precision assemblies where fine thread pitch is required for vibration resistance or load distribution. The plug chamfer provides a moderate lead-in, balancing ease of starting with thread engagement depth. It is a single-piece, right-hand tap intended for use in manual tap handles, tapping arms, or CNC rigid tapping setups where forward chip evacuation is preferred.

Key Features

• Spiral point geometry drives chips forward for clean through-hole threading
• High speed steel construction provides wear resistance across steel and aluminum applications
• Plug chamfer for moderate lead-in and reliable thread engagement
• H2 thread limit maintains 2B class of fit dimensional tolerances
• Bright finish for visibility and general-purpose use without coating-related tolerancing concerns
• Right-hand cut, no coolant-through requirement for standard tapping environments

Compatibility

Designed for through-hole threading of 1/4-28 UNF right-hand internal threads in alloy steel, carbon steel, and aluminum workpieces. Compatible with standard tap handles, tapping heads, and rigid CNC tapping setups accepting a 0.255-inch shank diameter.

Installation Notes

Secure the workpiece and ensure the through-hole is drilled to the correct tap drill diameter for 1/4-28 UNF before threading. Apply appropriate cutting fluid for the workpiece material to extend tool life and improve thread finish. Use a tap wrench, tapping arm, or rigid tapping cycle with consistent feed to avoid tap breakage. Inspect the tap for wear or chipping regularly, as a worn tap can produce out-of-tolerance threads or seize in the hole.