Cleveland C54583 Hand Tap 3/8-16 Unc Plug 4-flute Hss

Product Description

The CLEVELAND C54583 is a 3/8-16 UNC straight-flute 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 provides a balanced entry angle suited for general-purpose threading work across a wide range of materials. It runs 4 flutes with a right-hand thread direction, a Class 3B fit, and an H3 thread limit, making it appropriate for applications that require close-tolerance threading. Overall length is 2.938 inches with a 0.75-inch thread length. Licensed machinists and toolroom technicians are the primary users of this tap.

The C54583 is suited for production and maintenance threading operations on alloy steel, carbon steel, aluminum, and free-machining stainless steel. The plug chamfer — typically 3 to 5 threads of taper — allows the tap to start easily in a pre-drilled hole and is appropriate for both blind-hole and through-hole applications. The straight-flute design keeps chips manageable and the tool profile simple, making it a reliable choice for hand tapping and low-speed machine tapping setups in shop and field environments.

Key Features

• 3/8-16 UNC thread form, Class 3B fit, H3 thread limit for close-tolerance internal threads
• High speed steel construction for durability across ferrous and non-ferrous materials
• Bright uncoated finish — no coating buildup concerns, straightforward resharpening
• 4-flute straight-flute geometry for stable chip control in blind and through-hole work
• Plug chamfer for easy starting and versatile use across both hole types
• Right-hand thread direction, compatible with standard tap wrenches and tapping heads

Compatibility

Designed as an OEM-style replacement or standard toolroom tap for 3/8-16 UNC internal threading applications in alloy steel, carbon steel, aluminum, and free-machining stainless steel workpieces.

Installation Notes

Use appropriate cutting fluid or tapping compound for the workpiece material to reduce friction and extend tap life. Always start the tap square to the pre-drilled hole using a tap guide or drill press when precision alignment is required. Back off periodically during hand tapping to break and clear chips, particularly in blind-hole applications. Follow standard shop safety practices and secure the workpiece firmly before beginning the threading operation.