Osg 1121800 Straight Flute Tap 7/16-14 Unc 4 Flutes

Product Description

The OSG 1121800 is a straight flute tap designed for cutting 7/16-14 UNC internal threads in a wide range of ferrous and non-ferrous materials. Built from high-speed steel with a bright, uncoated finish, this tap features a taper chamfer that guides the tool into the hole gradually, reducing entry force and improving thread start accuracy. With 4 flutes and an H3 thread limit, it produces consistent thread tolerances suited to standard fastener fits. Overall length is 3-5/32 inches, thread length is 1-7/16 inches, and the shank diameter measures 0.323 inches. Machinists and toolroom professionals install this tap in manual or CNC tapping operations where straight-flute geometry suits through-hole and blind-hole applications in machinable materials.

The OSG 1121800 is suited for tapping aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The taper chamfer style makes it a practical choice for starting threads in through holes or where a gradual lead-in is preferred over plug or bottoming styles. It is commonly used in job shops, maintenance operations, and production environments where 7/16-14 UNC fastener threads are required. The right-hand thread direction and H3 tolerance class align with standard inch-series fastener specifications across general mechanical assembly.

Key Features

• 7/16-14 UNC right-hand thread form with H3 thread limit for consistent tolerance control
• Taper chamfer provides gradual thread lead-in, reducing tap breakage risk on entry
• 4-flute straight design suitable for through-hole and short blind-hole tapping
• High-speed steel construction provides good wear resistance across listed material applications
• Bright, uncoated finish compatible with standard cutting fluids and tapping compounds
• No coolant-through feature - intended for conventional flood or manual lubrication

Compatibility

Designed as an OEM-style replacement or direct-use tap for 7/16-14 UNC thread applications in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel per OSG Series 101.

Installation Notes

Installation should be performed by a qualified machinist following standard tapping procedures. Power down or disengage the spindle before loading or removing the tap from the holder. Always apply an appropriate cutting fluid or tapping compound for the workpiece material to extend tool life and improve thread finish. Follow shop safety protocols and applicable OSHA machine guarding requirements when operating tapping equipment.