Regal Cutting Tools 008691AS Straight Flute Tap 1-1/2-12 Unf

Product Description

The REGAL CUTTING TOOLS 008691AS is a straight flute tap designed for cutting internal 1-1/2-12 UNF threads in metalworking and manufacturing applications. Built from high-speed steel (HSS) with a bright/uncoated finish, it delivers reliable performance in a wide range of ferrous and non-ferrous materials. The tap features 6 flutes, a plug chamfer for standard through-hole and blind-hole threading, and a right-hand thread direction. With an overall length of 6.375 inches and a thread length of 3 inches, it is sized for production and maintenance threading operations performed by machinists, tool and die makers, and maintenance technicians.

This tap is suited for industrial threading tasks where a 3B class of fit is required, providing the standard tolerance range used in most general-purpose UNF fastener applications. The plug chamfer style makes it appropriate for starting threads in through holes or in blind holes with sufficient depth clearance. It is commonly used in machine shops, maintenance facilities, and manufacturing environments for tapping large-diameter fine-pitch threads in fixtures, housings, and structural components. The H4 thread limit designation indicates the pitch diameter allowance, ensuring consistent thread geometry across production runs.

Key Features

• 1-1/2-12 UNF thread size with 12 threads per inch for fine-pitch threading
• 6-flute design promotes chip distribution and thread quality in larger-diameter taps
• Plug chamfer provides 3-5 thread lead-in, suitable for through holes and deep blind holes
• High-speed steel construction offers toughness and wear resistance across common workpiece materials
• 3B class of fit meets standard tolerance requirements for general-purpose UNF threaded assemblies
• H4 thread limit provides controlled pitch diameter for consistent fit
• Right-hand thread direction; no coolant-through feature

Compatibility

Designed for use in standard tap holders, machine tap chucks, and tapping heads that accept the shank diameter of 1.233 inches and square drive size of 0.925 inches. Suitable for machine tapping or hand tapping operations requiring 1-1/2-12 UNF 3B thread form.

Installation Notes

This tap should be installed and operated by qualified machinists or maintenance technicians familiar with threading operations. Ensure the workpiece is securely fixtured and the tap is properly aligned with the pilot hole before beginning the threading operation. Use appropriate cutting fluid for the workpiece material to extend tap life and improve thread finish. Follow applicable shop safety practices and equipment manufacturer guidelines when operating tapping machines or drill presses.