Osg 1100402 Straight Flute Tap 1/4-28 Unf Plug Hss

Product Description

The OSG 1100402 is a straight flute plug tap designed for cutting internal 1/4-28 UNF right-hand threads in a range of ferrous and non-ferrous materials. Built from high-speed steel, it features four flutes and a plug chamfer, making it suited for through-hole and moderately deep blind-hole tapping applications. The H1 thread limit provides close tolerance control, which is important when threading fastener holes that require predictable fit. Overall length is 2.5 inches, with a thread length of 1 inch. It is a manually and machine-guided tap used by machinists, maintenance technicians, and trade professionals who need reliable thread production in production and repair settings.

This tap is designed for use in tapping operations across a wide range of materials including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The plug chamfer style, with its moderate lead, works well for starting threads in through holes and is a common choice for general-purpose threading in both shop and field repair environments. The 1/4-28 UNF thread size is widely used in precision mechanical assemblies, instrument panels, and hydraulic fittings where a fine thread pitch is required.

Key Features

• 1/4-28 UNF thread size with right-hand thread direction for standard fastener applications
• Plug chamfer style provides a moderate lead suitable for through-hole and accessible blind-hole tapping
• Four flutes support chip clearance in a variety of common materials
• H1 thread limit for close tolerance control
• High-speed steel construction resists wear across a broad range of workpiece materials
• No coolant-through design - suitable for standard tapping with cutting fluid applied externally

Compatibility

Designed as a standard replacement or production tap for 1/4-28 UNF threaded hole applications in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces.

Installation Notes

Installation should be performed by a qualified machinist or maintenance technician using a tap wrench, tapping head, or CNC machine tool set to the appropriate feed rate. Power down and secure the workpiece before beginning the tapping operation. Apply a suitable cutting fluid or tapping compound to extend tap life and improve thread quality. Inspect the tap for wear or chipping before each use and replace if thread quality degrades.