Guhring 9039700063500 Spiral Flute Tap 1/4-20 Unc

Product Description

The GUHRING 9039700063500 is a spiral flute tap designed for blind hole threading in aluminum and aluminum alloy. Part of the Series 3970 line, it cuts a 1/4-20 UNC right-hand thread to a 2B class of fit. The cobalt construction with MolyGlide finish handles the galling tendencies common when threading soft, sticky aluminum. The 45-degree helix angle drives chips up and out of the hole, which is critical in blind applications where chip packing causes tap breakage. This tap is installed by machinists and maintenance professionals working in production or field environments.

This tap is suited for blind hole threading in aluminum and aluminum alloy workpieces where chip evacuation is the primary concern. The modified bottoming chamfer allows threading closer to the bottom of a blind bore than a plug or taper chamfer would permit. At 2.382 inches overall length with a 0.255-inch shank diameter, it fits standard tap holders and machine spindles used in CNC machining centers, drill presses, and tapping machines. Thread limit H4 and H5 accommodate standard 2B tolerance requirements in most aluminum threading applications.

Key Features

• 45-degree helix angle evacuates chips upward out of blind holes
• Modified bottoming chamfer threads closer to blind hole bottom than plug chamfer
• Cobalt construction provides heat and wear resistance over high-speed steel
• MolyGlide finish reduces friction and built-up edge when cutting aluminum
• H4 and H5 thread limits support 2B class of fit tolerance
• Right-hand flute and right-hand thread for standard tapping operations

Compatibility

Designed for blind hole threading in aluminum and aluminum alloy. Cuts 1/4-20 UNC threads to a 2B class of fit. Compatible with standard tap holders and spindles accepting a 0.255-inch shank diameter.

Installation Notes

Machinists and maintenance technicians install spiral flute taps using tapping machines, CNC machining centers, or hand-tap wrenches. Ensure the workpiece is securely fixtured before tapping. Use a cutting fluid appropriate for aluminum to supplement the MolyGlide finish and extend tool life. Never reverse a tap under power without confirming the machine is set to reverse; forcing a tap in the wrong direction or without chip clearance in a blind hole will cause breakage.