Osg 1005201208 Straight Flute Tap 7/16-20 Unf Bottoming

Product Description

The OSG 1005201208 is a straight flute bottoming tap designed for threading 7/16-20 UNF right-hand internal threads in production and maintenance machining applications. Built from powdered metal and finished with a TiCN coating, it delivers extended tool life in abrasive and high-volume cutting conditions. The bottoming chamfer allows threads to be cut close to the bottom of blind holes. With 4 flutes and an H3 thread limit, the tap maintains consistent dimensional accuracy across repeated use. Overall length is 3.9370 inches with a thread length of 1.4375 inches, making it suitable for standard tap holders and machine spindles.

This tap is rated for use in aluminum and cast iron and is suited to CNC machining centers, drill presses, and tapping machines where straight flute geometry is preferred for shorter chip materials. The straight flute design works best in materials that produce broken chips rather than long stringy chips. It is part of OSG Series 10052 and is packaged individually. Machinists, tool-and-die makers, and production operators in job shops and manufacturing facilities are the primary users of this tool.

Key Features

• Bottoming chamfer for threading close to the bottom of blind holes
• Powdered metal construction with TiCN coating for extended tool life in abrasive materials
• 4-flute straight flute design optimized for aluminum and cast iron
• H3 thread limit for consistent fit class across production runs
• Right-hand thread direction, 7/16-20 UNF specification
• No coolant-through requirement — compatible with flood or dry cutting setups

Compatibility

Designed for use in aluminum and cast iron workpieces requiring 7/16-20 UNF right-hand internal threads. Compatible with standard tap holders accepting a 0.323 inch shank diameter.

Installation Notes

This tap is installed by a machinist or tool operator using a standard tap holder or collet chuck matched to the 0.323 inch shank diameter. Ensure the workpiece is securely fixtured and the pilot hole is drilled to the correct tap drill size for 7/16-20 UNF before tapping. Appropriate cutting fluid or lubricant should be applied for the workpiece material, even though coolant-through is not required. Inspect the tap for wear or chipping before each use to avoid thread quality issues.