Osg 1734400 Straight Flute Tap 5/8-11 Unc Cobalt Plug

Product Description

The OSG 1734400 is a straight flute machine tap designed to cut internal 5/8-11 UNC threads in ferrous materials. Built from cobalt high-speed steel with a bright, uncoated finish, it delivers reliable performance in tough workpiece materials where heat buildup and tool wear are primary concerns. The plug chamfer style eases thread entry and distributes cutting load across several leading threads. With 4 flutes and an H3 thread limit, this tap holds tight tolerances for a 3B class of fit, making it appropriate for precision threaded assemblies in industrial and manufacturing environments. Licensed machinists and toolroom professionals are the primary users of this tap.

This tap is suited for through-hole and blind-hole threading applications in alloy steel, cast iron, die steel, and hardened steel. The straight flute geometry works best in these short-chipping materials where chip evacuation back out of the hole is predictable and controlled. It is commonly used in manual tapping operations and CNC machining centers where coolant-through tooling is not required. The Series 305 designation identifies this as part of OSG standard machine tap line for general-purpose inch-thread production work.

Key Features

• Cobalt high-speed steel construction for improved heat and wear resistance in hard ferrous materials
• Bright, uncoated finish suited for use with cutting oil or soluble coolant applied externally
• Plug chamfer distributes cutting load over the first several threads for smooth entry
• 4-flute straight design optimized for short-chipping materials including cast iron and alloy steel
• H3 thread limit holds 3B class of fit tolerances for precision threaded connections
• Right-hand thread cutting, no coolant-through required

Compatibility

Designed for threading 5/8-11 UNC holes in alloy steel, cast iron, die steel, and hardened steel workpieces in machine tapping applications where straight flute geometry and external coolant delivery are appropriate.

Installation Notes

This tap is installed in a standard tap holder or floating tap collet on a drill press, mill, or CNC machining center. Always ensure the tap is properly aligned to the pre-drilled hole before engagement to prevent tap breakage. Power down or de-energize the machine before changing tooling. Apply cutting oil or appropriate cutting fluid to the tap and workpiece when tapping to extend tool life and improve thread finish.