Osg 1405008808 Thread Forming Tap 5/16-18 Unc Bottoming

Product Description

The OSG 1405008808 is a thread forming tap in the EXOTAP VP-NRT series, designed for cold-forming internal threads without cutting or producing chips. Built from powdered metal high-speed steel (PM-HSS) with a TiCN coating, it handles the 5/16-18 UNC thread form with a bottoming chamfer of 1 to 1.5 threads. The bottoming chamfer allows threading to within a few threads of the bottom of a blind hole. Overall length is 2.719 inches, with a shank diameter of 0.318 inches. Licensed machinists and toolroom technicians install this tap in CNC machining centers or manual drill presses for production threading applications.

This tap is suited for blind hole threading in a range of ferrous and non-ferrous materials. It performs in alloy steel, carbon steel, die steel, hardened steel, stainless steel, and aluminum. The EXOTAP VP-NRT series is developed for applications where chip-free threading is required, such as thin-walled parts, deep blind holes, or assemblies where loose chips would cause quality issues. It is a right-hand thread tap with an H9 thread limit.

Key Features

• Thread forming (chipless) design eliminates chip evacuation concerns in blind holes
• Powdered metal high-speed steel construction for improved wear resistance and toughness over conventional HSS
• TiCN coating reduces friction and extends tool life in abrasive and hard materials
• Bottoming chamfer (1 to 1.5P) allows threading close to the base of blind holes
• H9 thread limit for controlled fit in precision threaded assemblies
• Compatible with material application codes P, M, and N covering steel, stainless, and non-ferrous alloys

Compatibility

Designed for blind hole threading in alloy steel, carbon steel, die steel, hardened steel, stainless steel, and aluminum per OSG EXOTAP VP-NRT series material application specifications.

Installation Notes

Thread forming taps require a proper forming tap drill size, which is larger than a standard cut-tap drill - consult published forming tap drill charts for the 5/16-18 UNC form before drilling. Adequate tapping fluid or cutting oil appropriate for the workpiece material should be applied before tapping. Ensure the spindle is aligned perpendicular to the workpiece to avoid tap breakage, especially in harder materials. Operate within the recommended RPM range for the material and tap diameter to avoid galling or thread distortion.