MIL-HDBK-62624, DEPARTMENT OF DEFENSE HANDBOOK: COBALT BASE ALLOY INVESTMENT CASTINGS (27 JAN 1998)., This handbook gives guidelines for chemical, mechanical and physical properties for investment castings of the cobalt alloy commercially known as L-605, Haynes 25, or Unitemp L605. This handbook is for guidance only. This handbook can not be cited as a requirement. If it is, the contractor does not have to comply.