Fatigue strength is presented of phenolic laminates 1/4, 1/8, and 1/16 inch in thickness under repeated load. Laminates were of CTL-91LB phenolic resin reinforced with 181-A1100 glass fabirc. Fatigue strength values were determined by applying axial loads parallel to the wary direction of the glass fabric reinforcement at 5, 25, and 900 cycles per minute and at mean stress levels of zero pounds per square inch, 25 and 50 percent of the compression control strength, and at 50 percent of the tension control strength. Specimens were evaluated at 73, 400, 500, 600, and 800 F. Results are presented in tables, and S-N curves (Maximum applied stress versus number of cycles to failure). (Author).