Osg 2865200 Thread Forming Tap 8-32 Unc Bottoming Hss

Product Description

The OSG 2865200 is a bottoming-style thread forming tap designed for 8-32 UNC threads with a 2B class of fit. Unlike cutting taps, thread forming taps displace material rather than cut it, producing stronger threads with no chips. Manufactured from high speed steel with a bright finish, this tap is suited for blind hole threading in ductile materials. It measures 2.125 inches overall length with a thread length of 0.374 inches and a shank diameter of 0.168 inches. The bottoming chamfer of 1.5 to 2 threads allows threading close to the bottom of a blind hole. Right hand thread direction applies.

This tap is intended for blind hole threading operations in aluminum, cast aluminum, low-carbon steel, and medium-carbon steel. It is commonly used in production machining, maintenance and repair, and fabrication environments where 8-32 UNC fastener holes are required in ductile workpiece materials. The bottoming geometry is particularly useful when full thread engagement depth is needed near the base of a drilled hole. Part of the OSG HY-PRO NRT series, it is packaged individually.

Key Features

• Bottoming chamfer with 1.5 to 2 chamfered threads for threading close to blind hole bases
• Thread forming design displaces material instead of cutting — eliminates chips and produces stronger threads
• High speed steel construction for durability across a range of ductile metals
• Bright finish, no coating — allows visual wear inspection
• Right hand thread direction, 32 threads per inch, 8-32 UNC
• Square drive end: 0.131 inches square size, 0.250 inches square length for positive tap wrench engagement

Compatibility

Designed for blind hole threading in aluminum, cast aluminum, low-carbon steel, and medium-carbon steel workpieces requiring 8-32 UNC, 2B class of fit threads. Not recommended for cast iron, hardened steel, or non-ductile materials where thread forming taps are not applicable.

Installation Notes

Thread forming taps require a dedicated forming tap drill size — not the standard tap drill for cutting taps — so verify the correct pilot hole diameter before use. Secure the workpiece and use a calibrated tap wrench or CNC tapping head set to the appropriate feed rate for the material. Apply cutting fluid or tapping lubricant appropriate for the workpiece material to reduce forming forces and extend tap life. If tapping by hand, advance with steady forward pressure and back off periodically to relieve stress.