Import BDNA-20755 Straight Flute Tap 12-28 Unf Hss

Product Description

The IMPORT BDNA-20755 is a straight flute plug tap designed for cutting 12-28 UNF internal threads in through-holes and shallow blind holes. Built from high-speed steel (HSS) with a gold oxide coating, this tap offers improved lubricity and modest corrosion resistance during cutting operations. It features 4 flutes and a plug chamfer, which distributes cutting load across several leading threads for controlled thread engagement. The overall length is 2.375 inches. Right-hand thread direction and an H3 thread limit make it suitable for standard tolerance threading applications in ferrous and non-ferrous materials.

This tap is used in machine shops, maintenance facilities, and field service applications where 12-28 UNF threaded holes are required. The plug chamfer style is the most common general-purpose choice, appropriate for both through-holes and holes with sufficient depth beyond the threaded section. It is compatible with standard tap wrenches and tapping heads. Machinists, tool-and-die techs, and mechanical maintenance trades install this type of tap routinely in production and repair work.

Key Features

• 12-28 UNF thread form for fine-pitch unified national thread applications
• 4 straight flutes provide balanced cutting action and chip clearance
• Plug chamfer distributes entry load across multiple leading threads
• High-speed steel construction withstands heat generated during tapping
• Gold oxide coating reduces friction and provides light corrosion protection
• H3 thread limit suits standard commercial tolerance fits
• Right-hand thread direction for conventional tapping operations

Compatibility

Designed as a general-purpose replacement or stock tap for applications requiring 12-28 UNF internal threads. Compatible with standard tap wrench drives and tapping fixtures sized for the shank of a No. 12 tap.

Installation Notes

Use the correct drill size for a 12-28 UNF tap before threading to ensure proper thread engagement. Apply cutting fluid appropriate for the workpiece material to extend tap life and improve thread quality. Ensure the tap is started straight and perpendicular to the workpiece surface to avoid tap breakage. Back off periodically when hand-tapping to break chips, especially in deeper holes.