Abstract: A pipe harness clamp for use when two pipes, which may be of different materials, are axially coupled, includes arcuate clamping portions for contacting outer surfaces of a pipe and radially extending portions for bolting together. An elastomeric liner is fitted around the pipe, under the clamp, to assure a close fit between the pipe contour and the clamp. Stiffening gussets extend on the outside of the clamp between the arcuate clamping portions and the radially extending portions, in a plane substantially perpendicular to the axis of the pipe. Preload washers, such as disk washers, are provided on the clamping bolts to control preload. A plurality of washers may be used on each bolt. Belleville washers are preferred. The belleville washers compensate for any relaxation of the clamp halves and bolts and preload is not significantly reduced, thus maintaining load capacity of the clamp.