Osg 1608307 Straight Flute Tap M8x1.25 Metric Coarse 6H

Product Description

The OSG 1608307 is a straight flute tap designed to cut M8x1.25 metric coarse internal threads in metallic workpieces. It features a plug chamfer style, 4 flutes, and a 6H class of fit with a D5 thread limit, making it well-suited for general-purpose tapping where standard thread tolerances are required. The tap is manufactured from high-speed steel and finished with a nitride/oxide coating to improve surface hardness and reduce galling during cutting. With an overall length of 2-23/32 inches and a thread length of 1-1/8 inches, it fits standard tap holders and machines used in production and maintenance environments. This tool is installed by machinists, tool and die makers, and maintenance technicians.

The OSG 1608307 Series 141C straight flute tap is suited for tapping through holes and short blind holes in aluminum and cast iron workpieces. The straight flute geometry works effectively in these materials because chips tend to break rather than curl, making evacuation manageable in typical through-hole applications. It is appropriate for use in manual tapping operations as well as CNC or drill press setups where coolant-through capability is not required.

Key Features

• M8x1.25 metric coarse thread form with 6H class of fit and D5 thread limit
• Plug chamfer style for general-purpose starting and through-hole tapping
• 4-flute straight flute geometry optimized for aluminum and cast iron
• High-speed steel construction for durability across a range of cutting conditions
• Nitride/oxide coating improves wear resistance and reduces friction at the cutting edge
• Right-hand thread direction; no coolant-through feature

Compatibility

Designed for tapping M8x1.25 metric coarse threads in aluminum and cast iron. Compatible with standard tap holders sized for a 0.318-inch shank diameter. Part of the OSG Series 141C straight flute tap line.

Installation Notes

Power down or disengage the machine spindle before loading or changing taps. Secure the tap in a properly sized tap holder or collet to prevent runout and thread misalignment. Use an appropriate cutting fluid or tapping compound for the workpiece material - aluminum and cast iron have different lubrication requirements. Inspect the tap for wear or chipping before each use, as a damaged tap can produce out-of-tolerance threads or break inside the workpiece.