British Buttress (BBUT) U-Type Threading Inserts

Product Overview

Tackle the largest unidirectional power threads with our British Buttress U-Type laydown threading inserts. While standard tools handle medium pitches, these heavy-duty carbide threading inserts are designed for the extreme forces required to machine coarse BBUT threads (7° pressure flank, 45° clearance flank).

Featuring a “Full Profile” geometry, these inserts cut the full thread depth and finish the crest in a single operation. The U-Type design utilizes a larger insert size to provide the structural integrity needed for 4 TPI or 3 TPI threads—tasks that are impossible for a standard 16er threading insert to perform due to the depth of cut required.

Key Features & Benefits

• Extreme Load Capacity: The 7° load-bearing flank transmits massive axial force, while the U-Type insert body prevents vibration during machining.
• Coarse Pitch Specialist: Specifically designed for 4 TPI and 3 TPI threads found on heavy British machinery.
• Comparison: A standard 16er threading insert (3/8″ I.C.) lacks the mass to support these coarse threads; our 22U and 27U series are the dedicated solution.
• Directional Options: We stock comprehensive solutions, including left hand thread insert models (e.g., 27U EL 3 BBUT) for counter-rotating mechanisms.