arco (de una escobilla)

Spanish to English Tech/Engineering Mechanics / Mech Engineering

Hello. From operations for assembly of a wiper blade:

"PUNZONAR, MARCAR Y CORTAR DESARROLLO. ARCO CENTRAL"

"DOBLAR DESARROLLO. ARCO CENTRAL"

Also appears in a potential fault:

"Ausencia taladro acoplamiento con arco intermedio"

Thanks for your help :)