Osg 2866808 Thread Forming Tap 3/8-24 Unf Ticn Hss

Product Description

The OSG 2866808 is a thread forming tap designed for bottoming applications in blind holes. It cuts a 3/8-24 UNF right-hand thread to a 2B class of fit using a cold-forming process that displaces material rather than cutting chips, producing stronger threads with better surface finish. Manufactured from high-speed steel with a TiCN coating, it resists heat and wear during tapping operations. The bottoming chamfer provides 1.5 to 2 thread lead-in, allowing the tap to reach full thread depth close to the bottom of blind holes. It belongs to the OSG HY-PRO NRT series and is suited for production and maintenance machining environments.

This tap is engineered for blind hole threading in aluminum, cast aluminum, low-carbon steel, and medium-carbon steel workpieces. It is appropriate for use in machine shops, toolrooms, and manufacturing facilities where consistent thread quality and tool life are priorities. The TiCN coating extends tool life in abrasive and higher-volume applications. Its overall length of 2.9380 inches and shank diameter of 0.3810 inches fit standard tap holders and CNC tooling setups used by machinists and toolmakers.

Key Features

• 3/8-24 UNF thread size with 2B class of fit for standard unified fine-thread applications
• Bottoming chamfer with 1.5 to 2P lead-in for threading close to the bottom of blind holes
• Thread forming (chipless) design strengthens threads by cold-working the material
• High-speed steel construction provides toughness across a range of workpiece materials
• TiCN coating improves surface hardness and reduces friction for extended tool life
• Right-hand thread direction compatible with standard tapping equipment and tap holders

Compatibility

Rated for use in aluminum, cast aluminum, low-carbon steel, and medium-carbon steel (material application codes P and N). Designed for blind hole threading applications requiring a 3/8-24 UNF 2B thread form.

Installation Notes

Thread forming taps require a different pilot hole diameter than cutting taps — use the recommended forming tap drill size for the specific material to avoid over-stressing the tap. Apply appropriate tapping fluid or cutting oil before and during operation; dry tapping is not recommended. Secure the workpiece firmly and ensure the tap is aligned axially with the hole before beginning the tapping cycle. Follow applicable shop safety procedures and machine tool manufacturer guidelines when operating in CNC or manual tapping setups.