The sliding knobs were designed to be used on a plastics thermoforming mold to allow for thermal expansion of the tooling. This allows the user to change out a mold while it is still hot, rather than waiting for it to cool down and return to “ambient size”. Please click the corresponding yellow button above to view the proper layout of the knobs for thermal expansion. These knobs slide in one direction only, and positioning them in the recommended layout allows your warm tooling to grow thermally in all directions. Use of the sliding knobs for other purposes such as providing extra “play” or “slop” may or may not work. Thorough testing is recommended for all non-standard concepts and applications of the sliding knobs.