Westward
Westward 5TWU4 Pipe Tap 1-1/2"-11-1/2 Semi-Bottoming 7 Flutes NPT
A pipe tap that cuts NPT threads with seven flutes, 75 percent thread depth and a 1.7188 inch drill size
- TypeHole, Drill, Bore & Wire Gauges
- Cuts precise NPT threads with 7-flute semi-bottoming design
- High-speed steel construction delivers long tool life
- Right-hand cutting orientation matches standard pipe threading
- 75 percent thread drill size 1.7188 in ensures accurate fit
- Bright uncoated finish resists corrosion in workshop environments
Pipe Tap for 1-1/2" NPT Threads
This Westward pipe tap cuts internal threads to the 1-1/2"-11-1/2 NPT standard. It features a semi-bottoming chamfer with seven flutes and is made from high-speed steel with a bright uncoated finish. The tool has a right-hand thread direction and a class 3B fit.
Upgrade from Taper or Plug Chamfer Taps
A semi-bottoming design allows threading closer to the bottom of a blind hole than standard taper or plug chamfers. The switch is worth it when hole depth limits prevent a longer lead-in. The 75 percent thread drill size of 1.7188 in prepares the hole for the 75 percent thread engagement this tap produces.
Suited for Maintenance and Repair Threading
Mechanics and pipefitters cutting NPT threads in steel or iron pipe and conduit will find this tap matches the required specification. It is not intended for high-volume production runs where coated or specialised geometry taps reduce cycle time. Buyers needing a different thread form or size should select the corresponding tap.
Highlights
- Cuts precise NPT threads with 7-flute semi-bottoming design
- High-speed steel construction delivers long tool life
- Right-hand cutting orientation matches standard pipe threading
- 75 percent thread drill size 1.7188 in ensures accurate fit
- Bright uncoated finish resists corrosion in workshop environments
Specifications
| Brand | Westward |
|---|---|
| Type | Hole, Drill, Bore & Wire Gauges |
Questions about this item
What drill size is required for the 1-1/2"-11-1/2 NPT tap?
Use a 1.7188 in drill to produce the 75 percent thread depth this tap is designed for.
How do I start the tap straight in the hole?
Apply steady pressure while turning the square drive clockwise; the semi-bottoming chamfer helps alignment but the first full turn must be perfectly perpendicular.
When should the tap be replaced?
Replace it when the 7 flutes show visible wear or when threads cut in high-speed steel no longer gauge to a 3B class of fit.
Also in this aisle
People compared these
Same shelf, same checkout — eight coins and a 30-minute rate lock.



