Osg 1073502 Straight Flute Tap 8-32 Unc Bottoming Hss

Product Description

The OSG 1073502 is a straight flute bottoming tap designed to cut internal threads in pre-drilled holes where full thread depth is required close to the bottom of a blind hole. Manufactured from high-speed steel (HSS), it produces right-hand 8-32 UNC threads with a 2B class of fit and an H3 thread limit for consistent dimensional control. With 2 flutes and a bottoming chamfer, this tap is suited for finishing passes after a taper or plug tap has started the thread. Overall length is 2.125 inches with a thread length of 0.75 inches. Machinists, toolmakers, and maintenance technicians rely on this tap for precise threading in a range of ferrous and non-ferrous materials.

The OSG 1073502 is intended for tapping operations across a broad range of common workpiece materials including aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel. It is well suited for both production and maintenance environments where 8-32 UNC threads are a standard fastener specification. The bottoming chamfer makes it especially useful in blind-hole applications where thread engagement must extend as close to the hole bottom as possible.

Key Features

• Bottoming chamfer for maximum thread depth in blind holes
• High-speed steel construction for durability across ferrous and non-ferrous materials
• 2B class of fit with H3 thread limit for controlled tolerance threading
• 2-flute design promotes chip clearance in through and blind hole applications
• Right-hand thread direction, 8-32 UNC standard
• Compact 2.125-inch overall length suited for confined workspaces

Compatibility

Designed for tapping 8-32 UNC threads in aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel workpieces. Suitable as an OEM-style replacement or standard toolroom tap wherever 8-32 UNC bottoming taps with H3 tolerance are specified.

Installation Notes

This tap is installed by machinists and toolroom technicians using a tap wrench, tapping head, or CNC tapping cycle. Always ensure the pilot hole is drilled to the correct tap drill size for 8-32 UNC before use. Apply appropriate cutting fluid for the workpiece material to extend tool life and improve thread finish. When tapping blind holes, use a taper or plug tap first, then finish with this bottoming tap to achieve full thread depth.