Cleveland C54788 Hand Tap 5/8-18 Unf Plug 4-flute Hss

Product Description

The CLEVELAND C54788 is a 5/8-18 UNF straight-flute hand tap designed for cutting internal threads in both blind holes and through-holes. Manufactured from high speed steel with a bright (uncoated) finish, this plug chamfer tap features four flutes and a right-hand thread direction. It carries a Class 3B fit and an H3 thread limit, making it suitable for applications where close-tolerance threading is required. Overall length is 3.813 inches with a thread length of 1.09 inches. Licensed machinists and tool-and-die technicians rely on this tap for production and maintenance threading operations.

The C54788 is well suited for threading operations on a range of ferrous and non-ferrous materials, including alloy steel, carbon steel, aluminum, and free-machining stainless steel. Its plug chamfer — typically 3 to 5 threads of lead — makes it effective as a starting tap or as the only tap used in through-hole applications. It is appropriate for both manual hand-tapping and use in low-speed machine tapping setups in job shop, maintenance, and manufacturing environments.

Key Features

• 5/8-18 UNF right-hand thread, Class 3B fit with H3 thread limit for close-tolerance work
• Plug chamfer design suitable for through-hole threading and as a starting tap in blind holes
• 4-flute straight-flute geometry provides chip clearance and stable thread form
• High speed steel construction delivers durability across a broad range of workpiece materials
• Bright (uncoated) finish — no coating buildup in the flutes, straightforward to inspect and resharpen
• Compatible with both blind hole and through-hole threading applications per Series 1002 design

Compatibility

Designed for use in alloy steel, carbon steel, aluminum, and free-machining stainless steel workpieces requiring a 5/8-18 UNF internal thread. Applicable to both blind hole and through-hole threading operations as stated by the manufacturer.

Installation Notes

Installation should be performed by a qualified machinist or maintenance technician familiar with hand and machine tapping procedures. Always secure the workpiece and use an appropriate tapping fluid or cutting oil matched to the workpiece material before beginning the threading operation. For blind holes, clear chips frequently by reversing the tap to prevent binding or tap breakage. Ensure the tap is started square to the workpiece to maintain thread alignment and avoid cross-threading.