Accupro T1634643 Spiral Flute Tap 5/8-11 Cobalt

Product Description

The ACCUPRO T1634643 is a spiral flute tap designed for threading 5/8-11 inch holes in ferrous and hard materials. Built from cobalt high-speed steel with an oxide finish, it delivers heat and wear resistance under demanding tapping conditions. The modified bottoming chamfer allows threading close to the bottom of blind holes, making it a practical choice for tight-tolerance work. With a right-hand flute direction and a 33-degree helix angle, chips are pulled up and out of the hole efficiently. This tap is used by machinists, tool-and-die makers, and maintenance technicians working with manual or CNC tapping equipment.

This tap is suited for production and repair tapping in blind-hole applications where a standard bottoming chamfer is required but with slightly more lead-in than a full bottoming tap. The 3B class of fit with an H3 thread limit produces a standard-tolerance internal thread appropriate for most fastener and assembly applications. It is commonly used in steel, cast iron, and stainless steel workpieces across manufacturing, maintenance, and fabrication environments.

Key Features

• Cobalt construction provides elevated heat resistance for tapping hard and abrasive materials
• Modified bottoming chamfer enables threading close to the bottom of blind holes
• 33-degree right-hand helix angle promotes efficient chip evacuation in blind-hole tapping
• Oxide finish reduces friction and improves lubrication retention during cutting
• H3 thread limit and 3 3B class of fit ensure standard-tolerance threads for general assembly
• No coolant-through design suited for conventional tapping with applied cutting fluid

Compatibility

Designed as a direct-fit spiral flute tap for 5/8-11 UNC threaded blind-hole applications requiring a modified bottoming chamfer and 3 3B class of fit.

Installation Notes

This tap is installed by qualified machinists or maintenance technicians using a tap wrench, tapping head, or CNC tapping attachment rated for the shank diameter. Always apply appropriate cutting fluid for the workpiece material before and during tapping. Secure the workpiece firmly and ensure the tap is started square to the hole to prevent tap breakage. Do not reverse-drive a broken tap with cutting tools not rated for cobalt material extraction.