Consists of the records of Automotive Machinist Union, Lodge No. 1305, originally founded in San Francisco and later including Marin County, Oakland, and Eureka. The collection spans the years 1919 to 1970, and includes minutes of the executive board, bylaws, correspondence, agreements, ledgers, a roll book, membership applications, clearance cards, organizing leaflets, legal cases, correspondence with the Grand Lodge, and records of a sister machinists union, Lodge No. 1414.