Milwaukee Tool 49-57-5189 Straight Flute Tap 1/8-27 Npt

Product Description

The MILWAUKEE TOOL 49-57-5189 is a straight flute tap designed to cut internal 1/8-27 NPT threads in pipe fittings, couplings, and threaded ports. Built from high-carbon steel with a black oxide finish, it provides corrosion resistance and reduced friction during the tapping operation. The taper chamfer lead eases thread entry and distributes cutting forces gradually across the first several threads. With 4 flutes and a 2B class of fit, this tap produces threads suited to standard pipe thread assemblies where a leak-resistant seal is required. Plumbers, pipefitters, and machinists use this tap when threading new holes or cleaning up damaged NPT threads in steel, iron, or aluminum workpieces.

This tap is sized for 1/8-27 NPT, the thread standard commonly found on small pipe fittings, fuel line fittings, instrumentation ports, and hydraulic plugs in residential and light commercial plumbing and HVAC applications. The right-hand thread direction is compatible with standard threading practice. The overall length of 2.25 inches and thread length of 0.375 inches make it appropriate for through-holes and shallow blind-hole applications where standard NPT engagement depth is achievable.

Key Features

• 1/8-27 NPT thread size for standard small pipe thread applications
• 4-flute straight flute design for controlled chip evacuation in through-hole tapping
• Taper chamfer distributes cutting load gradually for easier thread entry
• 2B class of fit meets standard pipe thread assembly tolerances
• Black oxide finish reduces friction and provides light corrosion resistance
• High-carbon steel construction provides durability for general-purpose threading tasks

Compatibility

Designed as an OEM-style replacement tap for general-purpose 1/8-27 NPT threading applications in pipe, fittings, and ported components.

Installation Notes

This tap is installed by a machinist, pipefitter, or plumber using a standard tap wrench or machine spindle. Always apply cutting fluid appropriate to the workpiece material before and during tapping to reduce heat and extend tool life. Ensure the workpiece is securely clamped and the tap is started perpendicular to the hole surface to avoid cross-threading. Follow applicable IPC or IFGC code requirements when threading pipe fittings that will carry pressurized fluids or gas.