An instructor's manual and student activity guide on making an adjustable C-clamp are provided in this set of prevocational education materials which focuses on the vocational area of trade and industry (metal work). (This set of materials is one of ninety-two prevocational education sets arranged around a cluster of seven vocational offerings: agriculture, home economics, distributive education, health occupations, world of work, trade and industry, and office occupations.) The instructor's guide is organized into the following elements: title of activity, duration of activity (six periods), activity goals, instructional objectives, and activity implementation (description, materials needed, safety considerations, teacher preparation prior to class, during the class, follow-up activities, and masters for duplication [e.g., final drawings of project, student answer sheet]). The student activity guide provides step-by-step instructions (narrative and illustrations) for completing each instructional objective (e.g., measure and cut stock, die threads in rod stock). At the end of each set of instructions is a student check point (evaluation activity). Occupational descriptions for a drill press operator, contour band-saw operator, and machinist conclude the document. (JH)