Guhring 9039320111130 Spiral Flute Tap 7/16-20 Unf

Product Description

The GUHRING 9039320111130 is a spiral flute tap designed for blind hole threading in aluminum and aluminum alloy workpieces. Built from cobalt high-speed steel with a bright, uncoated finish, this tap cuts a 7/16-20 UNF right-hand internal thread to a 2B class of fit. The 2-flute, fast-flute design with a 45-degree helix angle efficiently evacuates chips up and out of the hole during the tapping operation. The modified bottoming chamfer allows threading closer to the bottom of a blind bore than a standard taper or plug tap. Licensed machinists and tool-and-die professionals use this tap in production and maintenance environments where close-tolerance unified fine threads are required.

This tap is suited for blind hole applications in aluminum and aluminum alloy components, making it a common choice in aerospace, automotive, and precision machining shops. The H4/H5 thread limit provides the slight oversize needed to accommodate plating or anodizing stock allowances where applicable. The Series 3932 designation identifies this as part of a family of spiral flute taps engineered for non-ferrous and softer materials. No coolant-through feature is incorporated, so flood or mist coolant delivery at the spindle is the standard approach when used in CNC or manual tapping cycles.

Key Features

• Cobalt HSS construction for improved heat resistance and tool life in aluminum alloys
• 45-degree helix angle with fast flute style for efficient chip evacuation in blind holes
• Modified bottoming chamfer for threading close to the bottom of blind bores
• H4/H5 thread limit accommodates post-process surface treatment stock allowances
• Right-hand flute and right-hand thread, 2-flute configuration
• Bright, uncoated finish - no coating buildup risk in non-ferrous materials

Compatibility

Designed for blind hole threading in aluminum and aluminum alloy workpieces requiring a 7/16-20 UNF, 2B class of fit internal thread. Compatible with standard 0.3230-inch shank tapping chucks, holders, and quick-change tapping heads sized for that shank diameter.

Installation Notes

This tap is installed by a machinist or toolroom technician in a tapping chuck or rigid holder mounted in a drill press, machining center, or tapping machine. Ensure the correct tapping speed for cobalt tooling in aluminum is observed per the tool manufacturer or shop standard. Apply an appropriate cutting fluid or coolant for aluminum tapping to prevent galling and extend tool life. Inspect the pre-drilled hole diameter against the recommended tap drill size for 7/16-20 UNF before tapping to ensure proper thread engagement and avoid tool breakage.