Osg 1123400 Straight Flute Tap 9/16-18 Unf Plug Hss

Product Description

The OSG 1123400 is a straight flute tap designed for cutting internal threads in a wide range of ferrous and non-ferrous metals. It produces 9/16-18 UNF right-hand threads using a plug chamfer, which makes it suitable for through-hole tapping where the tap can run past the bottom of the hole. Built from high-speed steel with a bright, uncoated finish, the tool offers solid wear resistance across common shop materials. The 4-flute design provides good chip control and thread form accuracy in standard tapping operations. Overall length is 3-19/32 inches with a thread length of 1-21/32 inches.

This tap is intended for production and maintenance tapping in ferrous and non-ferrous materials including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The plug chamfer style makes it a general-purpose choice for most through-hole applications in both manual and machine tapping setups. It fits standard tap wrenches and machine tool holders sized for its 0.429-inch shank diameter. Series 101 designation indicates OSG standard tooling geometry for this thread profile.

Key Features

• 9/16-18 UNF thread form with right-hand thread direction
• Plug chamfer for through-hole tapping applications
• 4 straight flutes for chip control in short-chip materials
• High-speed steel construction for durability across carbon steels and aluminum
• Bright uncoated finish - no coating interference with tight-tolerance H3 thread limit
• H3 thread limit for standard UNF fits

Compatibility

Designed as a standard replacement or production tap for through-hole 9/16-18 UNF tapping in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel applications.

Installation Notes

This tap is installed by a machinist or toolmaker using a tap wrench, tapping head, or CNC machine tool holder. Ensure the workpiece is securely clamped and the tap is properly aligned to the pilot hole before engagement to avoid tap breakage. Apply appropriate cutting fluid for the workpiece material before beginning the tapping cycle. For machine tapping, confirm spindle speed and feed rate are appropriate for the material and tap diameter before starting.