Osg 1013900 Straight Flute Tap 6-40 Unf Hss Taper

Product Description

The OSG 1013900 is a straight flute tap designed to cut internal 6-40 UNF threads in a wide range of metallic workpiece materials. Manufactured from high-speed steel with a bright, uncoated finish, this taper chamfer tap is suited for hand tapping and machine tapping operations where chip evacuation is manageable in through-hole or open setups. It carries a Class of Fit of 2B and 3B with a Thread Limit of H2, providing the dimensional control required for standard UNF fastener applications. The 3-flute geometry, right-hand thread direction, and taper chamfer make entry and thread alignment straightforward in production and maintenance environments.

This tap is intended for use in ferrous and non-ferrous materials including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. It is well suited to light manufacturing, toolroom work, and field maintenance applications where 6-40 UNF threaded holes are required. The taper chamfer configuration makes it particularly effective as a starter tap when threading by hand or when initiating threads in a drill press or tapping head setup. Licensed machinists, tool and die technicians, and maintenance mechanics are the primary installers.

Key Features

• 6-40 UNF thread form with right-hand thread direction and H2 thread limit for controlled dimensional tolerance
• Taper chamfer distributes cutting load over multiple leading threads for easier entry and reduced breakage risk
• 3-flute straight flute design is effective in through-hole applications across a broad range of materials
• High-speed steel construction provides toughness and resistance to wear in general-purpose tapping applications
• Bright, uncoated finish is compatible with standard cutting fluids and tapping compounds
• No coolant-through requirement simplifies use in manual and standard machine setups

Compatibility

Designed as a general-purpose OEM-style straight flute tap for cutting 6-40 UNF internal threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces. Part of OSG Series 102.

Installation Notes

Always secure the workpiece firmly and use a proper tapping fluid or cutting compound appropriate to the workpiece material before beginning thread cutting. Power down any machine tool and confirm zero motion before mounting or removing taps from chucks or holders. When hand tapping, use a calibrated tap wrench and back off the tap periodically to break chips and reduce the risk of tap breakage. Inspect the tap for chipping or wear before each use and replace if cutting edges show signs of degradation.