Milwaukee Tool 49-57-5155 Straight Flute Plug Tap 7/16-14 Unc

Product Description

The MILWAUKEE TOOL 49-57-5155 is a straight flute plug tap designed for cutting internal threads in through-holes and moderately deep blind holes. Built from high-carbon steel with a black oxide coating, this tap produces 7/16-14 UNC right-hand threads to a Class 2B fit. The 4-flute straight flute geometry channels chips back out of the hole, making it well-suited for use in softer metals, plastics, and other materials that produce broken chips. Machinists, maintenance techs, and metalworking professionals reach for this tap when restoring or cutting standard UNC fastener threads in production and repair applications.

The 49-57-5155 is intended for right-hand 7/16-14 UNC threading operations where a plug chamfer is appropriate. The plug chamfer — typically 3 to 5 threads of taper — makes it versatile for both through-hole and moderately deep blind-hole work. With an overall length of 3.25 inches and a thread length of 1.25 inches, this tap fits standard tap wrenches and machine tap holders used in drill press and CNC tapping setups. It does not include coolant-through capability and is not oversized.

Key Features

• 7/16-14 UNC thread form with Class 2B fit tolerance for standard fastener clearance
• Plug chamfer provides versatility for through-holes and moderately deep blind holes
• 4-flute straight flute design promotes chip control in brittle and short-chip materials
• High-carbon steel construction provides hardness suitable for threading softer workpiece materials
• Black oxide coating reduces friction and provides light corrosion resistance during storage and use
• Right-hand thread direction matches standard UNC fastener orientation

Compatibility

Designed as an OEM-style replacement tap for standard 7/16-14 UNC threading applications. Fits tap wrenches and machine tap holders accepting standard straight-shank taps of equivalent shank diameter.

Installation Notes

Tap installation should be performed by a qualified machinist or maintenance professional familiar with threading operations and applicable shop safety procedures. Always secure the workpiece fully before tapping and use appropriate cutting fluid to extend tap life and improve thread quality. Ensure the tap is started square to the hole to avoid cross-threading or tap breakage. When using in a machine setup, confirm spindle speed and feed rate are appropriate for the workpiece material before engaging the tap.