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Cleveland C55391 spiral point tap 3/8"-24 UNF TiCN coated

Cleveland

Cleveland C55391 Spiral Point Tap 3/8"-24 UNF 3 Flutes TiCN

SKU CH-4SD0-B6XBZ

Spiral-point tap cuts 3/8"-24 UNF threads in through-holes with three flutes and TiCN coating for longer wear

  • Spiral-point design pushes chips forward for smoother tapping in through holes
  • TiCN coating increases surface hardness and wear resistance on high-speed steel
  • 3/8"-24 UNF thread size matches standard fine-pitch fastening requirements
  • Three flutes balance chip clearance with cutting strength for consistent threads
  • H3 thread limit and 2B class of fit deliver precise tolerance control

Cleveland C55391 Spiral Point Tap

The Cleveland C55391 is a high-speed steel spiral point tap with a TiCN coating. It cuts unified national fine threads sized 3/8"-24 for through-hole applications. The plug chamfer and three-flute design suit general-purpose threading tasks in maintenance or production environments.

Check thread specification and hole preparation

Verify that the required thread form is UNF 3/8"-24 with a class 2B fit before ordering. The tap requires a 75 percent thread drill size of 8.50 mm for correct engagement. Confirm the workpiece material is compatible with high-speed steel tooling and right-hand cutting direction.

Behaviour under sustained cutting load

The TiCN coating increases surface hardness and reduces friction during extended threading cycles. Spiral point geometry pushes chips ahead of the flutes to prevent packing in deep through-holes. High-speed steel construction maintains edge retention at standard tapping speeds for repeated operations.

Highlights

  • Spiral-point design pushes chips forward for smoother tapping in through holes
  • TiCN coating increases surface hardness and wear resistance on high-speed steel
  • 3/8"-24 UNF thread size matches standard fine-pitch fastening requirements
  • Three flutes balance chip clearance with cutting strength for consistent threads
  • H3 thread limit and 2B class of fit deliver precise tolerance control

Specifications

BrandCLEVELAND

Questions about this item

Does the Cleveland C55391 tap come with a matching 8.50 mm drill bit or must I buy it separately?

Only the tap is supplied; the 8.50 mm drill for the 75 percent thread is not included.

Should I choose this H3-limit, 3-flute TiCN tap or a different limit for a standard 3/8"-24 UNF 2B hole?

The H3 limit is correct for a 2B class of fit in 3/8"-24 UNF threads.

How deep can I thread in one pass with the 16 mm thread length on this plug-style tap?

The 16 mm thread length sets the maximum full-thread depth per pass in a through hole.

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