Osg 1987000 Spiral Flute Tap M12x1.75 Bottoming 6H Hss

Product Description

The OSG 1987000 is a spiral flute bottoming tap designed for threading M12x1.75 metric coarse threads in blind holes. Made from high-speed steel (HSS) with a bright uncoated finish, it features a 50-degree helix angle and 3 right-hand flutes that efficiently evacuate chips up and out of the hole during the tapping operation. The bottoming chamfer allows threading to within a few pitches of the bottom of a blind hole. Overall length is 3.375 inches (85.7 mm), with a shank diameter of 0.367 inches (9.32 mm). Intended for use by machinists and maintenance technicians on manual machines, CNC tapping centers, and drill presses.

This tap is suited for blind-hole applications in production and job-shop environments where full thread depth close to the hole bottom is required. The D6 thread limit and 6H class of fit produce threads within standard tolerance for general-purpose metric fastener assembly. Compatible material applications include aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel, making it a versatile option across a range of common workpiece materials.

Key Features

• M12x1.75 metric coarse thread form, right-hand direction
• Bottoming chamfer for threading close to the bottom of blind holes
• 50-degree helix angle promotes chip evacuation in through and blind-hole applications
• D6 thread limit with 6H class of fit for standard metric tolerance
• High-speed steel construction - suitable for aluminum, cast iron, and carbon steel grades
• Bright uncoated finish - no coolant-through requirement

Compatibility

Designed for use in applications requiring M12x1.75 metric coarse bottoming threads across aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces.

Installation Notes

This tap is installed by machinists or maintenance technicians using a tap wrench, tapping head, or CNC rigid tapping cycle. Power down and lock out any machine spindle before loading or changing tooling. Use appropriate cutting fluid for the workpiece material - particularly important when tapping steel or cast iron. Do not reverse the tap under power without confirming the machine is configured for a synchronized tapping cycle, as unsupported reversal can break the tap in the hole.