Regal Cutting Tools 012358AS 1/2-28 Unef Plug Tap Hss

Product Description

The REGAL CUTTING TOOLS 012358AS is a straight flute plug tap designed to cut 1/2-28 UNEF internal threads in through-holes and shallow blind holes. Built from high speed steel (HSS) with a bright uncoated finish, this tap delivers reliable thread formation in a wide range of ferrous and non-ferrous workpiece materials. The plug chamfer geometry - typically 3 to 5 threads of lead - distributes cutting load gradually, making it well-suited for general-purpose tapping in production and maintenance environments. With 4 flutes and an H3 thread limit, this tap holds close dimensional tolerances for fit-critical threaded connections.

This tap is used in machining, toolroom, and maintenance-repair-operations (MRO) settings wherever a 1/2-28 UNEF thread is required. The UNEF thread form is common in thin-walled components, optical mounts, and precision mechanical assemblies where a finer pitch is needed than standard UNF provides. It is installed by machinists and tool-and-die professionals using a tap wrench, tapping head, or CNC machine spindle. The straight flute design works best in shorter-chipping materials where chip evacuation is not a primary concern.

Key Features

• 1/2-28 UNEF thread form with right-hand cutting direction
• Plug chamfer for gradual load distribution in through-hole and shallow blind-hole applications
• High speed steel construction for durability across a range of workpiece materials
• Bright uncoated finish - no additional coating to affect thread limit sizing
• H3 thread limit for controlled tolerance on fit-critical assemblies
• 4 straight flutes for chip clearance in short-chipping materials

Compatibility

Designed as a standard hand and machine tap for cutting 1/2-28 UNEF right-hand internal threads. Compatible with standard tap wrenches, tapping attachments, and CNC tapping heads that accept the corresponding shank diameter and square drive of this tap size.

Installation Notes

Secure the workpiece firmly before tapping and ensure the tap is started square to the hole to prevent cross-threading or tap breakage. Always use an appropriate cutting fluid for the workpiece material to extend tap life and improve thread surface finish. When tapping on CNC equipment, verify spindle speed and feed rate are matched to the tap manufacturer recommendations for the material being threaded. Do not force a tap that feels tight - back off to break chips and re-apply cutting fluid before continuing.