Osg 1136100 Straight Flute Tap 1-8 Unc 4 Flute Plug Hss

Product Description

The OSG 1136100 is a straight flute tap designed for cutting 1-8 UNC internal threads in a range of ferrous and non-ferrous materials. It features a plug chamfer, H4 thread limit, and a 3B class of fit, making it suitable for general-purpose through-hole and blind-hole tapping where standard tolerance control is required. Built from high-speed steel with a bright, uncoated finish, this tap delivers reliable performance across common machining environments. With 4 flutes and a right-hand thread direction, it is sized at 5.125 inches overall length with a thread length of 2.5 inches. It is installed by machinists and toolroom professionals using standard tapping equipment.

This tap is suited for production and maintenance tapping in materials including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The plug chamfer style provides a gradual thread lead-in, making it appropriate for through-holes or holes with adequate chip clearance. The 4-flute straight flute geometry works well in shorter-chipping materials and standard machine tapping setups. The 1-8 UNC thread size is a common fastener specification found in structural, mechanical, and equipment assembly applications across industrial and manufacturing environments.

Key Features

• 1-8 UNC thread form with right-hand thread direction and 3B class of fit
• Plug chamfer for gradual thread engagement in through-holes or deep blind holes with clearance
• H4 thread limit for controlled oversize tolerance in standard machining applications
• 4 straight flutes suited to shorter-chipping materials including cast iron and carbon steels
• High-speed steel construction with bright, uncoated finish
• No coolant-through feature - designed for conventional flood or manual lubrication setups

Compatibility

Designed for tapping 1-8 UNC threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. Part of OSG Series 101.

Installation Notes

This tap is installed by machinists using manual tap wrenches, tapping heads, or CNC machine tools with rigid or floating tap holders. Ensure the workpiece is securely fixtured and the tap is properly aligned to the drilled hole before engagement to prevent tap breakage. Apply appropriate cutting fluid for the workpiece material before and during tapping. Power down or disengage spindle drive before manually backing out the tap or performing any tool changes.