Osg 1987001 Spiral Flute Tap M12x1.75 Bottoming 6H Hss

Product Description

The OSG 1987001 is a spiral flute tap designed for cutting M12x1.75 metric coarse internal threads in a wide range of materials. It features a bottoming chamfer for threading holes to near-full depth, making it well suited for blind-hole applications where thread engagement close to the bottom of the bore is required. The tap is manufactured from high-speed steel with a steam oxide coating that reduces friction and helps resist built-up edge during cutting. With 3 flutes and a 50-degree helix angle, the spiral geometry evacuates chips up and out of the hole efficiently. Overall length is 3.375 inches. This is a right-hand tap producing right-hand threads to a 6H class of fit and D6 thread limit.

This tap is used in machining, maintenance, and repair applications across manufacturing, tooling, and field service environments. It is appropriate for threading aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The bottoming configuration is especially useful in CNC machining centers, manual mills, and drill press setups where shallow blind holes require maximum thread depth. Licensed machinists, toolmakers, and skilled maintenance mechanics are the primary users of this tool.

Key Features

• Bottoming chamfer allows threading to near-full depth in blind holes
• 50-degree helix angle promotes efficient upward chip evacuation
• Steam oxide coating reduces friction and extends tool life in ferrous materials
• 6H class of fit and D6 thread limit for standard metric tolerance compliance
• Right-hand flute direction and right-hand thread for conventional tapping operations
• Compatible with aluminum, cast iron, and carbon steel workpiece materials

Compatibility

Designed for cutting M12x1.75 metric coarse right-hand threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. Suited for use with standard tap holders and tapping heads that accept a 0.367-inch shank diameter.

Installation Notes

This tap should be installed in a properly sized tap holder or tapping chuck rated for the shank diameter before use. Always ensure the workpiece is securely fixtured and the spindle is aligned with the pre-drilled pilot hole before beginning the tapping cycle. For blind-hole applications, confirm hole depth is sufficient to accommodate both the tap chamfer length and the required thread engagement before starting. Use an appropriate cutting fluid for the workpiece material to maximize tool life and thread quality.