Abstract: A mine roof anchor assembly usable with a quick-setting resin cartridge inserted into a mine roof opening includes a partially threaded elongated bolt having a head at one end, a bail-type mechanical anchor at the threaded end, and an elongated helical coil having an upper end attached to the bolt and positioned external of and surrounding a substantial length along the bolt. A bearing plate and a two-faced washer can be positioned on the bolt head. Both sides of the washer may be coated with a dry lubricant such as graphite suspended in a resin base.

Abstract: The anchor bolt assembly is of the tensionable type used in mine roofs and the like in which the anchor bolt assembly is positioned in a bore hole of a rock formation. The bolt assembly includes an elongated bolt shaft with a head at one end and is threaded on the other end and has a mechanical expansion anchor on the threaded end. A bearing having a central opening is positioned on the bolt to engage a face of the rock formation. A two faced graphite coated washer is positioned on the bolt between the bolt head and the bearing plate. During installation, the washer acts as an anti-friction bearing between the bolt head and the plate to improve the torque to tension relationship.