A summary is presented of the status of the Department of Defense Refractory Metals SheetRolling Program to accelerate the development of production techniques for high-quality, consistent sheet products from the refractory metals (Nb, Mo, Ta, and W) and their alloys. The program includes: (1) development of sheet production techniques, (2) establishment of minimum data re uired to evaluate mill production, (3) evaluation of fabrication characteristics of the sheet produced, and (4) establishment of design data. Contracts were awarded for the development of sheet production techniques for all four refractory metals. One contract was awarded for the evaluation of Mo alloy sheet fabrication characteristics. (Author).

THE ACHIEVEMENT AND MAINTENANCE OF DESIRED DIMENSIONS IN COMPLEX, PRECISION-BUILT STRUCTURES, SUCH AS ROCKET-MOTOR CASES, ARE CRITICAL AND TECHNICALLY INVOLVED PROBLEMS. Their proper functioning demands close dimensional tolerances. Dimensional stability is extremely difficult toACHIEVE IN STEELS AT ULTRAHIGH STRENGTH LEVELS. The problem stems from interacting metallurgical factors which manifest themselves in volumetric and shape changes. The principal sources of size change are the changes in specific volume accompanying the phase transformations which occur in hardening and tempering. Distortion occurs when a part deforms in response to stress. The problem of dimensional instability is analyzed, the factors involved are discussed, and recommendations are made regarding the control of these factors. (Author).