Guhring 9043770021840 Thread Forming Tap 2-56 Unc

Product Description

The GUHRING 9043770021840 is a thread forming tap designed for cutting 2-56 UNC internal threads in blind and through-hole applications. Unlike cutting taps, thread forming taps displace material rather than remove chips, producing stronger threads with a better surface finish. This tap is manufactured from High-Speed Steel-E-PM (powder metallurgy grade) and carries a TiCN coating for improved wear resistance and lubricity. With a 2BX class of fit and a modified bottoming chamfer of 2 to 3 threads, it is suited for threading close to the bottom of blind holes. Licensed machinists, tool-and-die makers, and maintenance technicians working on precision assemblies typically install this tap.

This tap is intended for use in steel, stainless steel, cast iron, and non-ferrous metals, covering material application codes P, M, K, and N. The modified bottoming chamfer makes it particularly useful when thread engagement must start near the bottom of a blind hole. Through-hole threading is also supported. With a flute-by-diameter ratio of 3xD and three oil grooves, it maintains adequate lubrication and thread form consistency across short, small-diameter holes common in precision mechanical and electrical assemblies.

Key Features

• Thread forming (chipless) design produces stronger threads and eliminates chip evacuation concerns in blind holes
• TiCN coating increases surface hardness and reduces friction during tapping
• High-Speed Steel-E-PM construction provides toughness and wear resistance beyond standard HSS grades
• Modified bottoming chamfer (2 to 3 threads) allows threading close to the bottom of blind holes
• Three oil grooves support consistent lubrication throughout the tapping operation
• Right-hand thread direction, 2BX class of fit, H3 and H4 thread limits for controlled tolerance output

Compatibility

Designed for blind hole and through-hole threading in steel, stainless steel, cast iron, and non-ferrous metals where a 2-56 UNC thread form is required. Part of the GUHRING Series 4377.

Installation Notes

This tap should be installed in a tapping head, CNC machine, or hand tap wrench rated for small-diameter work. Ensure the workpiece is rigidly fixtured before tapping to prevent tap breakage at this small diameter. Apply an appropriate cutting fluid or tapping oil compatible with the workpiece material before and during the operation. Because this is a forming tap, the pilot hole diameter must be sized to the forming tap specification, not the standard cutting tap drill chart, to achieve the correct 2BX class of fit.