Kennametal 4130590 Spiral Flute Tap 1/2-20 Unf Bottoming

Product Description

The KENNAMETAL 4130590 is a spiral flute bottoming tap designed for threading 1/2-20 UNF holes in non-ferrous metals. Built from cobalt high speed steel with a straw finish, this tap delivers durability and heat resistance in demanding machining applications. The fast right-hand flute geometry with a 52-degree helix angle evacuates chips efficiently, pulling them up and out of the hole — a critical advantage in blind-hole tapping. With a 3B class of fit and H3 thread limit, it produces threads within close, commercially standard tolerances. Licensed machinists and toolroom technicians are the primary installers of this tooling.

This tap is suited for blind-hole and bottom-of-hole threading operations in non-ferrous metal workpieces, including aluminum, brass, and copper alloys. The bottoming chamfer style allows threading close to the bottom of a blind hole, maximizing usable thread depth. It fits standard tap holders and CNC rigid-tapping setups where right-hand spiral flute geometry is required. Coolant-through is not supported, making it appropriate for conventional flood or mist cooling setups.

Key Features

• 1/2-20 UNF right-hand thread, 3B class of fit with H3 thread limit for tight commercial tolerances
• 52-degree right-hand helix angle pulls chips up and out of blind holes
• Bottoming chamfer for maximum thread depth in blind-hole applications
• Cobalt high speed steel construction for elevated heat and wear resistance
• Straw finish reduces friction and provides a visual temper reference
• 3 flutes, fast flute style — optimized for non-ferrous material applications

Compatibility

Designed for threading 1/2-20 UNF blind holes in non-ferrous metals. Fits standard 0.367-inch shank tap holders and CNC rigid-tapping chucks accepting this shank diameter.

Installation Notes

This tap should be installed by a qualified machinist or toolroom technician familiar with tapping speeds and feeds for the target material. Ensure the machine spindle is stopped and de-energized before changing tooling. Use appropriate cutting fluid for the workpiece material even without coolant-through capability. Do not reverse the tap under power without confirming the machine is set for proper right-hand thread direction to avoid tool breakage.