Regal Cutting Tools 017860AS Straight Flute Tap 1-1/2-8 Uns Hss

Product Description

The REGAL CUTTING TOOLS 017860AS is a straight flute tap designed for cutting 1-1/2-8 UNS internal threads in ferrous and non-ferrous metals. Built from high-speed steel (HSS) with a bright, uncoated finish, this tap delivers consistent thread form in through-hole and shallow blind-hole applications. It features a plug chamfer with 4 flutes, providing a balance between chip clearance and thread engagement at the start. With an overall length of 6.375 inches and a thread length of 3.0 inches, it is sized for standard machine tapping operations on production floors and in maintenance shops.

This tap is suited for general-purpose threading in materials where HSS tooling performs reliably, including mild steel, cast iron, and aluminum. The plug chamfer style makes it appropriate for through-hole tapping or blind holes with adequate relief depth. It carries a right-hand thread direction and an H5 thread limit, making it compatible with standard H-limit toolholders and tapping heads used in machining centers, drill presses, and manual tapping fixtures. A shank diameter of 1.233 inches and a square drive size of 0.925 inches fit standard tap holders in this size range.

Key Features

• Thread size 1-1/2-8 UNS, right-hand thread direction
• Plug chamfer for through-hole or adequately relieved blind-hole applications
• 4 straight flutes for chip clearance and consistent thread form
• High-speed steel construction for durability across a range of metals
• H5 thread limit for controlled fit with standard tolerance requirements
• Bright, uncoated finish - no coating buildup to affect thread tolerance

Compatibility

Designed as a standard replacement or production tap for machining operations requiring 1-1/2-8 UNS internal threading; fits tap holders and tapping heads sized for a 1.233-inch shank diameter with a 0.925-inch square drive.

Installation Notes

This tap should be installed and operated by machinists or tool and die professionals familiar with tapping feeds, speeds, and cutting fluid requirements for the workpiece material. Secure the tap in a properly sized tap holder or floating tapping head before operation. Always ensure the workpiece is clamped rigidly and the pilot hole is drilled to the correct tap drill size for 1-1/2-8 UNS before starting. Do not reverse a tap under power without a reversing tapping head, as this can fracture the tool.