Osg 2868905 Thread Forming Tap M8x1.25 6H Bottoming Hss Tin

Product Description

The OSG 2868905 is a thread forming tap designed to cut M8x1.25 metric threads in blind holes using a cold-forming process that displaces material rather than cutting chips. Built from high-speed steel with a TiN coating, it delivers good wear resistance and extended tool life in production environments. The bottoming chamfer — with 1.5 to 2 chamfered threads — allows threading close to the bottom of a blind hole. With an overall length of 2.9527 inches and a tapping depth of 1.1260 inches, it fits standard tap holders and is suited for CNC machining centers and manual tapping operations alike. This tap belongs to the OSG HY-PRO NRT Series 286.

This tap is intended for blind hole threading in aluminum, cast aluminum, low-carbon steel, and medium-carbon steel. The thread forming method produces no chips, reducing the risk of chip packing in blind holes and improving thread strength through work hardening. It is commonly used in manufacturing, fabrication, and machine shops where M8x1.25 threaded holes are required in ferrous and non-ferrous materials. Right-hand thread direction is standard for conventional tapping operations.

Key Features

• Thread forming (chipless) design reduces chip packing risk in blind holes and improves thread strength
• TiN coating enhances surface hardness and reduces friction for longer tool life
• Bottoming chamfer (1.5 to 2 threads) enables threading close to the floor of blind holes
• High-speed steel construction provides toughness across a range of workpiece materials
• Right-hand thread direction compatible with standard tapping chucks and CNC rigid tapping
• 6H class of fit meets standard metric tolerance requirements for most general-purpose assemblies

Compatibility

Designed for blind hole threading in aluminum, cast aluminum, low-carbon steel, and medium-carbon steel per Material Application Codes P and N. Suitable for use with standard tap holders sized for an 8.08 mm shank diameter.

Installation Notes

Thread forming taps require the correct tap drill size for the material being tapped — consult the OSG HY-PRO NRT drill chart for M8x1.25 forming applications, as the correct drill diameter differs from cutting tap requirements. Always use a tapping fluid or cutting oil appropriate for the workpiece material to protect the TiN coating and maintain thread quality. Ensure the tap is properly aligned perpendicular to the workpiece surface before engagement to avoid tap breakage. For CNC applications, use rigid tapping mode with synchronized spindle and feed to match the 1.25 mm pitch.