Milwaukee Tool 49-57-5158 Straight Flute Tap M12 X 1.75

Product Description

The MILWAUKEE TOOL 49-57-5158 is a straight flute tap designed for cutting right-hand internal threads in through-holes and shallow blind holes. Built from high-carbon steel with a black oxide finish, it produces M12 x 1.75 metric threads to a Class of Fit 2B standard. The plug chamfer — with a lead of 3 to 5 threads — makes this tap well-suited for starting in pre-drilled holes where moderate guidance is needed before full thread engagement. With four flutes and a thread length of 38.10 mm, it handles a tapping depth of up to 36.1 mm. Licensed machinists, pipefitters, millwrights, and maintenance technicians are the primary users of this tool.

This tap is intended for use in general maintenance, repair, and fabrication applications involving metric fastener threads. It is suited for tapping aluminum, mild steel, cast iron, and similar ferrous and non-ferrous materials in both shop and field environments. The straight flute geometry makes it most effective in through-hole applications where chips can exit the hole freely. It is a single-piece, individually packaged tap appropriate for service trucks, tool cribs, and machine shop bench stock.

Key Features

• M12 x 1.75 metric thread size with right-hand thread direction
• Plug chamfer provides 3-5 thread lead-in for guided starting in pre-drilled holes
• High-carbon steel construction for hardness and wear resistance in general-purpose tapping
• Black oxide finish reduces friction and provides mild corrosion resistance
• 4-flute straight design channels chips out of through-holes during cutting
• Class of Fit 2B — standard tolerance for general-purpose metric fastener applications

Compatibility

Designed as an OEM-style replacement or service tap for general-purpose metric threading applications requiring an M12 x 1.75 straight flute plug tap with a 2B class of fit.

Installation Notes

Installation of this tap should be performed by a qualified tradesperson using a properly sized tap wrench or tapping fixture. Always ensure the workpiece is securely clamped and the pilot hole is drilled to the correct tap drill diameter for M12 x 1.75 threads before beginning. Apply cutting fluid appropriate to the workpiece material to reduce heat buildup and extend tap life. Back off the tap periodically to break chips and prevent binding, particularly in deeper holes.