These mounts should be keyed or pinned to prevent shifting during operation of cylinder. Keys or pins must be strong enough to resist full thrust of the cylinder. The lugs on (A) and (H) mounts are large enough to accommodate dowel pins. Extended key plate for stock and custom cylinder models available when specified. Pin or key the head whenever possible. Do not pin or key both ends. Cylinders become longer when pressure is applied, and tube will tend to buckle. The alignment and center-line height on mounting style (E) are maintained by accurately machined surfaces on the head and cap which are held against the mounting surface by the end lugs.