Product Description
Milwaukee 1/4 in.-18 NPT Straight Flute Taper Tap
Model Number: 49-57-5191
The Milwaukee 49-57-5191 is a 1/4 in.-18 NPT Straight Flute Taper Tap, precision machined for creating or repairing clean, accurate internal threads. Two things set this tap apart from a standard machine-screw tap. First, it is a taper tap: rather than the short chamfer of a plug tap, it has a longer, more gradual tapered lead of several threads that eases the tap into the hole for aligned, gradual starts, reducing the risk of cross-threading on the initial cut. Second, it cuts an NPT thread. NPT stands for National Pipe Taper, a tapered pipe thread used to join pipe and fittings and to create a pressure-tight seal for fluid and gas connections, which is a different job entirely from the straight machine threads that hold hardware together. The 1/4 in.-18 NPT designation identifies the nominal 1/4 in. pipe size with 18 threads per inch; note that the 1/4 in. is the pipe size, not the physical diameter, as a 1/4 in. NPT thread is roughly 0.540 in. across, larger than the nominal number suggests. The straight flute geometry clears chips as it cuts across common metals.
The tap is built for durability and lasting identification. High carbon steel construction holds a sharp cutting edge through the common metal applications it is designed for, and a protective black oxide coating resists corrosion and improves surface lubricity for a longer service life in the harsh environments where pipe threading happens. Milwaukee marks these taps with long-lasting laser-etched sizing rather than stamped markings, so the size stays clearly legible over the life of the tool. The square shank is compatible with all standard tap handles and tap wrenches, and the taper chamfer eases the tap into the work for a controlled, aligned start.
This taper tap is designed for cutting NPT pipe threads in the most common metal applications, including brass, aluminum, mild steel, and more, which makes it a go-to for plumbers, pipefitters, machinists, and maintenance crews threading ports and fittings for 1/4 in. NPT pipe connections, one of the most common pipe-thread sizes for air, hydraulic, and fluid ports. It handles both tapping fresh holes and chasing or repairing an existing damaged 1/4 in.-18 NPT thread. Because NPT is a tapered sealing thread, the depth to which the tap is run controls the final fit, so cut to the correct engagement for your fitting and remember that a thread sealant or tape is typically used on the assembled joint. For the cleanest finish, easiest cutting, and longest tap life, use the tap with cutting fluid to keep heat and friction down as it works.
Features
- Genuine Milwaukee 1/4 in.-18 NPT Straight Flute Taper Tap
- Cuts a tapered NPT pipe thread for sealed fluid and gas connections
- Taper tap with a long, gradual chamfer for aligned, gradual starts
- Reduces the risk of cross-threading on the initial cut
- The 1/4 in. is the nominal pipe size, not the physical diameter, about 0.540 in. across
- 18 threads per inch
- One of the most common pipe-thread sizes for air, hydraulic, and fluid ports
- High carbon steel construction for durability
- Black oxide coating for corrosion resistance and improved lubricity
- Long-lasting laser-etched sizing for the clearest identification
- Square shank fits all standard tap handles and tap wrenches
- Best used with cutting fluid for a clean finish and longer tap life
Specifications
- Manufacturer: Milwaukee Tool
- Part Number: 49-57-5191
- Type: Straight Flute Taper Tap
- Thread Size: 1/4 in. NPT (nominal pipe size)
- Thread Type: NPT (National Pipe Taper)
- Threads Per Inch: 18
- Chamfer: Taper, for gradual starts
- Flutes: Straight
- Material: High carbon steel
- Finish: Black oxide
- Shank: Square, fits standard tap handles and wrenches
- Part Type: Genuine Milwaukee Accessory
Includes
- (1) Milwaukee 49-57-5191 1/4 in.-18 NPT Straight Flute Taper Tap
