Value Collection MSC-04489555 Straight Flute Tap 1-3/8-12 Unf

Product Description

The VALUE COLLECTION MSC-04489555 is a straight flute tap designed for cutting internal threads in through-holes and shallow blind holes. Built from high-speed steel with a bright, uncoated finish, this tap produces 1-3/8-12 UNF right-hand threads to a 3B class of fit. The plug chamfer — tapered over several leading threads — eases entry into the workpiece and distributes cutting forces evenly across multiple flutes. With 6 flutes and an H4 thread limit, the tap holds tight tolerances suitable for precision fastener applications in metalworking, maintenance, and repair environments. Thread length is 3 inches over an overall length of 6-1/16 inches.

This tap is suited for machine shop, tool room, and field maintenance work where large-diameter unified fine threads are required. The 1-3/8-12 UNF specification is commonly found in hydraulic fittings, aerospace fasteners, precision machinery, and heavy equipment components. The plug chamfer style makes it a general-purpose choice for through-holes or holes with sufficient depth to accommodate the chamfer lead. It is intended for use by machinists, tool and die makers, and maintenance mechanics working in ferrous and non-ferrous metals with appropriate cutting fluid applied.

Key Features

• 1-3/8-12 UNF right-hand thread form for unified fine thread applications
• 6-flute design distributes cutting load and improves chip control in ductile materials
• Plug chamfer provides a balance between starting ease and thread engagement depth
• H4 thread limit maintains tolerance for 3B class of fit requirements
• High-speed steel construction offers durability across a range of workpiece materials
• Bright, uncoated finish allows direct inspection of tool condition and wear

Compatibility

Designed as a standard OEM-style replacement or new-installation tap for applications requiring 1-3/8-12 UNF internal threads in a 3B class of fit.

Installation Notes

This tap should be installed and operated by a qualified machinist using a calibrated tap handle or machine spindle with appropriate torque control. Power down or lock out any machine before securing the tap in the holder. Always apply a suitable cutting fluid for the workpiece material to reduce heat buildup and extend tool life. Do not reverse the tap suddenly under load — back off periodically to break chips and prevent tap breakage.