Guhring 9039100079380 Spiral Flute Tap 5/16-18 Unc

Product Description

The GUHRING 9039100079380 is a spiral flute tap designed for blind hole threading in demanding materials including aerospace alloys and stainless steel. It is ground from powdered metal and coated with titanium nitride (TiN) for extended tool life in abrasive and work-hardening materials. The tap cuts a 5/16-18 UNC right-hand thread to a 2B class of fit, with a modified bottoming chamfer that allows threading close to the bottom of a blind hole. Overall length is 2.72 inches. The 40-degree helix angle promotes efficient chip evacuation out of the hole, reducing the risk of tap breakage in tough alloys. Machinists and tool-and-die professionals typically specify this tap for CNC and manual tapping operations where chip control is critical.

This tap is suited for production and maintenance machining environments where 5/16-18 UNC blind holes are required in aerospace alloy and stainless steel workpieces. The modified bottoming chamfer makes it appropriate for applications where thread depth is close to the bottom of a drilled cavity. The fast flute style and 40-degree helix angle support use in materials that generate stringy or packed chips. It is sold individually and is appropriate for both manual tapping with a tap wrench and rigid CNC tapping cycles on machining centers equipped for that operation.

Key Features

• Modified bottoming chamfer for threading close to the bottom of blind holes
• 40-degree helix angle fast flute style for aggressive chip evacuation in stainless steel and aerospace alloys
• Powdered metal construction for improved wear resistance and toughness over standard HSS
• TiN coating reduces friction and extends tool life in abrasive materials
• Thread limit H4/H5 provides appropriate tolerance for 2B class of fit applications
• Right-hand flute and right-hand thread for standard tapping direction

Compatibility

Designed for cutting 5/16-18 UNC threads in aerospace alloy and stainless steel workpieces requiring blind hole threading to a 2B class of fit. Compatible with standard 5/16-18 tap holders and machine adapters accepting a 0.318-inch shank diameter.

Installation Notes

Installation is performed by qualified machinists following standard tapping procedures. Ensure the workpiece is securely fixtured and the tap is properly aligned before beginning the threading cycle to avoid tap breakage or thread distortion. Use a cutting fluid appropriate for the workpiece material, particularly when tapping stainless steel or aerospace alloys. When setting up on a CNC machining center, confirm that the tapping cycle parameters match the thread pitch before engaging the spindle.