Value Collection MSC-04489035 Straight Flute Tap 1-8 Unc

Product Description

The VALUE COLLECTION MSC-04489035 is a straight flute tap designed for cutting internal threads in through-holes and moderately deep blind holes. Built from high-speed steel with a bright, uncoated finish, this tap produces 1-8 UNC right-hand threads to a 3B class of fit, which meets standard commercial tolerance requirements for most threaded fastener applications. The taper chamfer — typically 7 to 10 threads — eases entry into the workpiece and distributes cutting load gradually, making it well-suited for hand tapping and machine tapping setups alike. With an overall length of 5.125 inches and a thread length of 2.5 inches, this tap handles large-diameter threading work in steel, cast iron, aluminum, and similar machinable materials.

This tap is used in general manufacturing, maintenance and repair, and fabrication environments wherever a 1-inch, 8-threads-per-inch unified coarse thread is required. The taper chamfer style makes it a common first-pass tool in a tap set sequence or the primary tap for through-hole applications. It is typically run in manual tap handles, tapping arms, or rigid-tapping CNC setups. The H4 thread limit designation indicates a slightly oversized thread form, which compensates for springback in harder materials and accommodates thread tolerances within the 3B fit range.

Key Features

• 1-8 UNC thread form with right-hand direction for standard unified coarse thread applications
• Taper chamfer distributes cutting load across 7 to 10 leading threads for easier starting
• High-speed steel construction provides toughness and wear resistance across a broad range of workpiece materials
• H4 thread limit optimizes fit tolerance in harder or springback-prone materials within the 3B class
• Bright, uncoated finish suits general-purpose use and allows visual wear inspection
• 4-flute geometry provides chip clearance and stable cutting action in through-hole threading

Compatibility

Designed as a standard replacement or tooling-room tap for any application requiring a 1-8 UNC taper tap in high-speed steel with a 3B class of fit and H4 thread limit.

Installation Notes

This tap is installed by machinists and toolmakers using a properly sized tap handle, tapping arm, or CNC rigid-tapping spindle. Always use cutting fluid appropriate to the workpiece material to reduce heat buildup and extend tool life. Ensure the tap is properly aligned with the drilled pilot hole before applying torque to prevent thread distortion or tap breakage. Follow applicable shop safety procedures and manufacturer feed-rate guidelines when running in powered tapping equipment.