Accupro T4677585 Spiral Flute Tap 1/2-20 4 Flute Nitride

Product Description

The ACCUPRO T4677585 is a spiral flute tap designed for cutting 1/2-20 UNF internal threads in ferrous and cast iron workpieces. It features a modified bottoming chamfer, allowing threads to be cut close to the bottom of blind holes. The tap is manufactured from 3 percent vanadium high speed steel (HSS) and carries a nitride finish that improves wear resistance and reduces friction during cutting. The 4-flute, slow-helix spiral flute design efficiently evacuates chips up and out of the hole, making it well-suited to through-hole and shallow blind-hole applications. Thread tolerance is held to an H5 thread limit with a 2B class of fit.

This tap is intended for use in machining, toolroom, and maintenance operations where 1/2-20 UNF threads are required. It is commonly applied in cast iron and similar ferrous materials. The right-hand flute and right-hand thread configuration make it compatible with standard CNC tapping cycles, drill press setups, and manual tapping operations. It ships individually and is appropriate for job-shop, production, and field-maintenance use where a precision-ground, coated HSS tap is specified.

Key Features

• Modified bottoming chamfer allows threading close to the bottom of blind holes
• 3 percent vanadium HSS construction provides increased toughness and wear resistance over standard HSS
• Nitride finish reduces friction and extends tool life in cast iron and ferrous materials
• H5 thread limit and 2B class of fit for consistent, inspectable thread quality
• 4-flute slow-helix spiral design promotes controlled chip evacuation
• Coolant-through feature is not required, simplifying setup

Compatibility

Designed as an OEM-style cutting tool for 1/2-20 UNF threaded holes in cast iron workpieces. Suitable for standard tapping heads, CNC machining centers, and manual tapping equipment that accept straight-shank taps with a 9.32 mm shank diameter.

Installation Notes

Installation is performed by machinists or maintenance technicians using standard tapping equipment. Ensure the workpiece is securely fixtured and the spindle is aligned to the pilot hole before beginning the tapping cycle. Apply appropriate cutting fluid for the material being tapped, even though coolant-through is not required. Follow shop safety procedures and applicable OSHA machine-guarding standards when operating tapping equipment.