Cleveland C54142 Hand Tap 4-40 Unc Plug 2-flute Hss

Product Description

The CLEVELAND C54142 is a 4-40 UNC hand tap designed for cutting internal threads in both blind holes and through-holes. Built from high speed steel with a bright uncoated finish, this plug-chamfer tap features two straight flutes and a right-hand thread direction. It is sized for the 4-40 thread standard, with an overall length of 1.875 inches and a thread length of 0.31 inches. The H1 thread limit keeps tolerances tight for a Class 2B fit. Machinists, toolmakers, and maintenance technicians reach for this tap when threading small-diameter fastener holes in production or repair environments.

This tap is suited for threading 4-40 holes in alloy steel, aluminum, carbon steel, and free-machining stainless steel. The plug chamfer — typically 3 to 5 threads of lead — makes it appropriate for both starter and finish tapping in through-holes and in blind holes where thread depth allows adequate chip clearance. It is a standard choice in job shops, assembly lines, and field maintenance settings where 4-40 threaded inserts or fasteners are common.

Key Features

• 4-40 UNC right-hand thread, Class 2B fit with H1 thread limit for consistent tolerance control
• Plug chamfer provides a balanced lead for use in through-holes and accessible blind holes
• Two straight flutes for chip evacuation in a range of workpiece materials
• High speed steel construction handles alloy steel, aluminum, carbon steel, and free-machining stainless steel
• Bright uncoated finish — no coating buildup to affect thread form on fine-pitch work
• Compact overall length of 1.875 inches fits standard tap wrenches and T-handle drivers

Compatibility

Designed as a standard hand tap for 4-40 UNC threaded holes. Compatible with alloy steel, aluminum, carbon steel, and free-machining stainless steel workpieces per Series 1002 application data.

Installation Notes

Hand taps should be installed and driven with a properly sized tap wrench to maintain axial alignment and prevent breakage. Secure the workpiece before tapping and use a suitable cutting fluid for the workpiece material to extend tap life and improve thread quality. Back the tap off a partial turn periodically to break chips, especially in blind holes. Always verify hole diameter against the recommended tap drill chart for 4-40 UNC before starting.