The Los Angeles abrasion machine is used to measure the degradation of mineral aggregate of standard gradings resulting from a combination of actions including abrasion or attrition, impact and grinding in a rotating steel drum containing a specified number of steel spheres. The test is widely used as an indicator of the relative quality of various sources of aggregate having similar mineral compositions.Humboldt's design follows the ASTM-preferred design and features a welded, structural-steel frame, fabricated .5"-thick (913mm) abrasion-resistant steel drum, a removable shelf, bolted to the drum and a balanced drum assembly for easy rotation by hand. The enclosed chain drive rotates the drum without a conventional slip clutch. This positive drive delivers greater accuracy. The self-contained worm-drive motorized speed reducer has anti-friction bearings and sealed lubrication. The 1hp, electronically-controlled motor is equipped large, push-button controls and an automatic overload cutout. Unit Includes user-configured, revolution counter, a material catch pan and one abrasion charge consisting of 12 hardened-steel balls. Dimensions: 39" x 29" x 37" (991 x 737 x 940mm). ASTM C131, C535; AASHTO T96