Osg 591 Straight Flute Tap M6x0.75 Metric Fine 3 Flutes

Product Description

The OSG 591 is a straight flute tap designed for cutting metric fine internal threads to the M6x0.75 specification. Built from high-speed steel (HSS) with a bright, uncoated finish, it carries a taper chamfer that guides the tap into the workpiece progressively, reducing the risk of misalignment at thread start. It produces a 2B class of fit, the standard tolerance for most metric fastener assemblies. With a 3-flute geometry and straight flute design, this tap is well suited to through-hole applications where chips can evacuate in line with the flute channel. Licensed machinists, tool-and-die tradespeople, and maintenance mechanics are the primary users.

This tap is used in production and maintenance applications where metric fine threading is required. The M6x0.75 pitch is common in precision assemblies, automotive components, and instrumentation where a finer thread pitch provides greater clamp load control than a coarse thread. The taper chamfer style makes it appropriate for through holes or as the first tap in a tapping sequence. It is rated for use in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel, covering a broad range of shop and field repair scenarios.

Key Features

• M6x0.75 metric fine thread specification with 2B class of fit for standard tolerance fastener assemblies
• Taper chamfer distributes cutting load gradually, reducing tap breakage risk at thread entry
• 3-flute straight flute geometry supports chip clearance in through-hole tapping operations
• High-speed steel construction provides wear resistance across a range of ferrous and non-ferrous materials
• Bright, uncoated finish suitable for use with cutting fluids across the listed material applications
• No coolant-through requirement simplifies setup on standard drill presses and tapping machines

Compatibility

Rated for tapping aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. Part of OSG Series 121.

Installation Notes

Tapping operations should be performed by qualified machinists or maintenance mechanics familiar with thread cutting procedures. Power down and secure the workpiece before beginning. Apply appropriate cutting fluid for the material being tapped to extend tap life and improve thread finish. Do not reverse the tap without allowing chips to break free, particularly in blind-hole setups, and avoid forcing the tap against the bottom of a hole.