Osg 1603007 Straight Flute Tap 1/2-13 Unc Bottoming Hss

Product Description

The OSG 1603007 is a straight flute bottoming tap designed to cut 1/2-13 UNC internal threads in blind holes where full thread depth is required close to the bottom of the bore. Built from high-speed steel with a nitride and oxide coating, it carries an H5 thread limit and a 2B class of fit. The 4-flute straight flute geometry keeps chips moving efficiently in short-chipping materials. Overall length is 3-3/8 inches with a thread length of 1-21/32 inches. Machinists, toolroom technicians, and maintenance trades use this tap in manual tapping, drill press, and CNC tapping operations.

This tap is suited for threading aluminum and cast iron workpieces where a standard bottoming chamfer is needed to maximize usable thread depth in blind holes. The Series 101C designation identifies it within the OSG standard tap line. The 2B class of fit is the general-purpose standard for most threaded fastener applications in both production and MRO environments. Right-hand thread direction is standard. The nitride and oxide surface treatment improves lubricity and wear resistance, extending tool life across repeated threading cycles in abrasive materials such as cast iron.

Key Features

• Bottoming chamfer allows threading to within 1-2 threads of the bottom of a blind hole
• High-speed steel construction provides toughness across a range of workpiece hardnesses
• Nitride and oxide coating improves wear resistance and reduces galling in cast iron and aluminum
• H5 thread limit ensures consistent 2B class of fit across production runs
• 4 straight flutes maintain rigidity and chip clearance in short-chipping materials
• Right-hand thread, no coolant-through requirement, compatible with standard tapping fluid application

Compatibility

Designed for threading 1/2-13 UNC blind holes in aluminum and cast iron workpieces. Suitable for use in manual tapping handles, drill press tapping heads, and CNC machining centers with rigid tapping capability.

Installation Notes

Secure the workpiece and ensure the tap is properly aligned perpendicular to the hole before beginning the threading operation. Apply an appropriate cutting fluid for the material being tapped - sulfurized oil for cast iron, light oil or aluminum-specific fluid for aluminum. Back the tap off periodically to break chips and prevent tap binding in deep blind holes. Inspect the tap for wear or chipping between uses, as a damaged tap can seize in the workpiece or produce out-of-tolerance threads.