Osg 1406100 Spiral Flute Tap 3-48 Unc Bottoming Hss

Product Description

The OSG 1406100 is a spiral flute bottoming tap designed to cut 3-48 UNC internal threads in blind or through holes. It features a 2-flute, right-hand spiral design with a 50-degree helix angle that efficiently evacuates chips up and out of the hole during tapping. The tap is manufactured from high-speed steel with a bright, uncoated finish and is rated to a 2B class of fit with an H2 thread limit. Overall length is 1.813 inches. Bottoming chamfer geometry allows threading close to the bottom of blind holes, making it the right choice when full thread depth near the bottom is required.

This tap is suited for light-duty threading applications in both production and maintenance environments. The 3-48 UNC size is commonly encountered in small fastener work, instrument assembly, and precision mechanical components. Material application data covers aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel. It is installed by machinists, tool and die technicians, and maintenance mechanics using a standard tap wrench or machine tapping setup.

Key Features

• Bottoming chamfer for threading close to the bottom of blind holes
• 50-degree right-hand helix angle for efficient chip evacuation
• High-speed steel construction for durability across a range of ferrous and non-ferrous materials
• H2 thread limit maintains consistent 2B class of fit tolerances
• Bright, uncoated finish - suitable for use with standard cutting fluids
• No coolant-through requirement simplifies setup

Compatibility

Designed for cutting 3-48 UNC threads in aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel workpieces. Compatible with standard tap wrenches and machine tapping holders accepting a 0.141-inch shank diameter.

Installation Notes

Always secure the workpiece before tapping and use an appropriate cutting fluid for the workpiece material to extend tap life and improve thread quality. For bottoming taps, drill the hole to the correct tap drill depth before threading to avoid contact between the tap tip and the bottom of the hole. Use a tap guide or properly aligned tapping head to keep the tap perpendicular to the workpiece surface. Inspect the tap for chipping or wear before each use, particularly in harder steels.