Cleveland
Cleveland C54789 Straight Flute Hand Tap 5/8"-18 UNF
A straight-flute hand tap cutting 5/8"-18 UNF threads in high-speed steel with a 1.81 in thread length and 3.81 in overall length
- TypeTaps
- Straight-flute design cuts clean threads in through-holes
- High-speed steel construction resists wear during repeated tapping
- 5/8"-18 UNF size matches standard fine-thread fasteners
- Bottoming chamfer reaches full depth in blind holes
- Bright uncoated finish suits general-purpose hand-tapping work
Cleveland C54789 Hand Tap for UNF Threading
The Cleveland C54789 is a straight-flute hand tap designed to cut 5/8"-18 UNF threads in through-holes or blind holes. It is made from high-speed steel with a bright, uncoated finish for general-purpose threading in ferrous and non-ferrous materials. The right-hand cut and H3 thread limit produce a class 2B fit. Machinists and maintenance technicians use it for repair work or short-run production where machine tapping is not practical.
Manual Operation Limits Chip Evacuation
Straight-flute geometry relies on the operator to reverse the tap frequently to break and clear chips, especially at the full 1.81 in thread length. The 75 percent thread drill size of 14.50 mm leaves minimal clearance for swarf in deep blind holes. Bottoming chamfer cuts threads close to the bottom but requires a pre-drilled hole deeper than the 3.81 in overall length. Hand tapping cannot match the speed or consistency of a powered tapping head.
5/8"-18 UNF Size Determines Fit
This tap cuts only 5/8"-18 UNF threads with an H3 limit for a class 2B fit. It will not produce metric, coarse UNC, or any other thread form or diameter. Select a different tap if the drawing calls for a different pitch, diameter, or class of fit. The H3 limit is not interchangeable with H1, H2, or higher limits without changing the resulting thread tolerance.
Highlights
- Straight-flute design cuts clean threads in through-holes
- High-speed steel construction resists wear during repeated tapping
- 5/8"-18 UNF size matches standard fine-thread fasteners
- Bottoming chamfer reaches full depth in blind holes
- Bright uncoated finish suits general-purpose hand-tapping work
Specifications
| Brand | CLEVELAND |
|---|---|
| Type | Taps |
Questions about this item
Should I choose the bottoming or a taper version for a through-hole?
This tap is a bottoming style, so it is intended for blind holes where threads must reach near the bottom. For a through-hole a taper or plug tap would start more easily.
What does the 5/8"-18 UNF size mean when I am cutting threads in steel?
It cuts a 5/8 inch diameter unified fine thread with 18 threads per inch, producing a class 2B fit when used with the recommended 14.50 mm drill.
How does the H3 thread limit affect the fit of the finished thread?
The H3 limit places the pitch diameter on the high side of the 2B tolerance band, giving a slightly tighter assembly than an H1 or H2 tap would produce.
Also in this aisle
People compared these
Same shelf, same checkout — eight coins and a 30-minute rate lock.
