The monobloc boom (also monoblock) is a single-piece, rigid excavator boom in contrast to the two-part articulated/variable boom. It offers higher rigidity and thus greater lifting capacity and breakout force, as no additional joint absorbs forces. Monobloc booms are the standard on most hydraulic excavators from 15 tonnes upwards.
The geometry of the monobloc boom is optimized for universal applicability: A forward-curved boom enables deep digging while maintaining good dumping height. Maximum digging depth is determined by the sum of boom length and stick length, minus the attachment height on the superstructure.
For specialized applications, manufacturers offer alternative boom configurations to the monobloc: articulated boom (knuckle) for variable working angles, longreach for waterway maintenance, and high-reach for demolition work. However, the monobloc remains the best-selling configuration, as it offers the best compromise between power, reach, and simplicity.