Osg 1122202 Straight Flute Tap 7/16-20 Unf Plug Hss H3

Product Description

The OSG 1122202 is a straight flute tap designed for cutting internal threads in a wide range of ferrous and non-ferrous materials. Built from high-speed steel, it produces a 7/16-20 UNF right-hand thread with a plug chamfer that makes it suitable for through-hole and most blind-hole applications. The 4-flute geometry provides stable cutting action and consistent chip formation. With a thread length of 1-7/16 inches and an overall length of 3-5/32 inches, this tap fits standard tap wrenches and machine collets used in production and maintenance tapping operations. The H3 thread limit offers a controlled fit for standard tolerance applications. Licensed machinists and maintenance technicians are the primary installers.

This tap is suited for tapping 7/16-20 UNF threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces. It is well matched to both hand tapping and machine tapping setups in industrial maintenance, manufacturing, and repair environments. The plug chamfer - typically 3 to 5 threads of lead - makes it a go-to choice when starting a tap in a pre-drilled hole where the full thread form is needed close to the bottom but some chamfer lead is acceptable.

Key Features

• 7/16-20 UNF thread form for fine-thread applications requiring higher pull-out strength
• High-speed steel construction provides hardness and wear resistance across a broad range of workpiece materials
• 4-flute straight design delivers stable cutting and reliable chip management in through and shallow blind holes
• Plug chamfer (H3 thread limit) supports general-purpose tapping with consistent thread tolerance
• Right-hand thread direction compatible with standard tap wrenches, tapping heads, and CNC rigid-tapping setups
• OSG Series 101 designation indicates standard production-grade geometry for high-volume or maintenance use

Compatibility

Designed for tapping 7/16-20 UNF threads in aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel. Compatible with standard tap wrenches and machine tapping collets sized for this shank diameter.

Installation Notes

Always use the correct drill size for a 7/16-20 UNF thread before tapping. Apply appropriate cutting fluid for the workpiece material - this tap does not support coolant-through delivery. Secure the workpiece firmly and ensure the tap enters the hole perpendicular to the surface to avoid tap breakage. Back the tap out periodically to clear chips when tapping deeper holes.