Abstract: A mast to base connection for a storage and retrieval machine which incorporates a pin connection between the mast and the base. The base of the machine is formed as a plurality of elongated plates standing on edge with upwardly extending lugs formed integrally with the plates. The mast has similar lugs formed at its lower end which interleave with the lugs on the base. The mast and base are factory prealigned prior to shipment and line bored to receive connecting pins which can be precisely matched to each bore. The invention includes a method by which the mast is assembled to the base at a job site by laying the mast down on the base and inserting one of the connecting pins into the lugs, and then tilting the mast about the pin until the remaining lugs are aligned for insertion of a second pin.