Guhring 9044073028450 Spiral Flute Tap 4-40 Unc Cobalt

Product Description

The GUHRING 9044073028450 is a spiral flute tap designed for blind hole threading in a 4-40 UNC thread form. Built from cobalt high-speed steel with an oxide finish, it delivers heat and wear resistance needed when tapping hard and abrasion-prone materials. The modified bottoming chamfer allows threading closer to the bottom of a blind hole than a standard plug tap, making it well-suited for tight-depth applications. With a 40-degree helix angle and right-hand flute direction, the tap efficiently evacuates chips upward during the cut. This tool is sized at 1.882 inches overall length with a 0.275-inch thread length and an H3 thread limit for controlled tolerance. It is installed by machinists and tool and die professionals in manual or CNC tapping operations.

This tap is rated for blind hole threading across a broad range of metallic workpiece materials. It is appropriate for use in light production and repair machining environments where a 4-40 UNC thread is required. The 3-flute fast-flute design provides efficient chip flow in through and blind hole conditions, though its modified bottoming chamfer specifically suits shallow-depth blind holes. The Series 4407 designation identifies it within the GUHRING product line for this tap geometry and coating family.

Key Features

• Modified bottoming chamfer for threading close to the bottom of blind holes
• Cobalt construction for improved heat resistance in tough and alloyed materials
• 40-degree helix angle promotes upward chip evacuation in blind hole conditions
• H3 thread limit supports 2B and 3B class of fit requirements
• Oxide finish reduces friction and provides mild corrosion resistance
• Right-hand flute and right-hand thread configuration for standard tapping direction

Compatibility

Rated for use in alloy steel, alloy tool steel, aluminum alloy, case hardened steel, cast iron, ductile iron, free cutting steel, heat treated steel, malleable cast iron, stainless steel, structural steel, and tool steel workpieces. Coolant-through is not supported by this tap.

Installation Notes

This tap is installed by machinists using a tap wrench, tapping head, or CNC rigid tapping cycle. Power down or de-energize any machine spindle before manually changing tooling. Use appropriate tapping fluid or cutting oil for the workpiece material to extend tool life and improve thread quality. Do not exceed the recommended tapping depth of 0.709 inches to avoid tool breakage in blind holes.