Milwaukee Tool 49-57-5157 Straight Flute Tap 7/16-20 Unf

Product Description

The MILWAUKEE TOOL 49-57-5157 is a straight flute plug tap designed to cut 7/16-20 UNF internal threads in through-holes and shallow blind holes. Manufactured from high-carbon steel with a black oxide coating, it offers adequate wear resistance and lubrication retention for general-purpose tapping in softer base materials. The plug chamfer provides 3-5 threads of lead-in, making it the standard choice for most production and maintenance tapping operations. With 4 flutes and a right-hand thread direction, this tap suits hand tapping and machine tapping setups where chip evacuation forward is acceptable.

This tap is suited for use in maintenance, repair, and fabrication environments where 7/16-20 UNF fine-thread fasteners are standard. It is commonly used by machinists, millwrights, and maintenance technicians working on mechanical assemblies, automotive components, and general metal fabrication. The overall length of 3.25 inches and a thread length of 1.25 inches make it practical for standard bench and drill-press tapping fixtures. It ships individually and carries a minimum order quantity of one.

Key Features

• 7/16-20 UNF right-hand thread form for fine-pitch internal threading
• Plug chamfer with 3-5 thread lead-in for general through-hole and shallow blind-hole tapping
• High-carbon steel construction suitable for tapping aluminum, mild steel, and similar softer materials
• Black oxide coating improves lubrication retention and provides mild corrosion resistance
• 4-flute geometry balances chip clearance and thread-form support
• Class 2B thread fit for standard tolerance internal threads

Compatibility

Designed as a standard straight flute plug tap for hand tapping and light machine tapping operations requiring a 7/16-20 UNF thread; verify base material hardness and tapping speed are within the range suitable for high-carbon steel tooling before use.

Installation Notes

This tap is installed by a machinist or maintenance technician using a tap wrench, tapping head, or drill press with appropriate tapping attachment. Always apply cutting fluid appropriate for the workpiece material to extend tool life and improve thread quality. Secure the workpiece firmly before tapping and ensure the tap enters perpendicular to the drilled hole. Do not use this high-carbon steel tap on hardened steel or stainless steel without verifying material suitability.