Design & Materials

Cosmec’s pot bearing designs draw from experience, full-size bearing testing, and the latest technology. Our team has total design and manufacturing experience in excess of 50 years, and we participate in creating the very latest specifications.

Our designs are based on using ASTM A709 Grade 50 (AASHTO M270 Grade 50) steel and ASTM A709 Grade 50W (AASHTO M270 Grade 50W) weathering steel. ASTM A709 Grade 36 (AASHTO M270 Grade 36) will be considered on demand. We prefer to maintain a maximum pressure on both the elastomer and the primary PTFE surfaces of 3500 psi. PTFE on guided surfaces may be stressed considerably higher.

The brass sealing rings are of such strength that one can effectively seal the elastomer, but typically three rings are provided for a wide margin of safety and design redundancy. They are open-ended and sprung so that they can accommodate tolerances of pot manufacture and shape changes during rotation. They are constantly pressed against the pot wall by the pressures within the elastomer.

All materials for all US bearings will be certified domestic material, manufactured and fabricated in the USA in accordance with the “Buy American” requirements for all federally funded work.

Material specifications include ASTM A240 Type 304 and Type 316 stainless steel with a #8 mirror finish; AASHTO Grade 50 Durometer elastomer; and ASTM D4894 PTFE; ASTM B36 for the brass.

Testing can be undertaken to fulfill all requirements of the AASHTO Specifications and any other specialized testing as may be required. Most testing can be performed in our own testing facilities.

Coating on the bearings can be the latest high-performance paints, including high-solids zinc primers, or the bearing assemblies can be metallized (zinc or zinc/aluminum thermal spray coatings). Galvanizing of the carbon steel components can be considered on demand. Coating recommendations can be made to ensure a long-lasting product, no matter the environment.