bearing chock: mass production of the company bearing chassis trailer, all sold in North America, has been 6 years export history.According to the U.S. MPIF-35 FC-0208 standard production, density :6.4-6 .5g/cc, hardness: HRB50-55. we can according to your requests to make many kinds of bearings ,because we have strong technical force,we have the confidence that we are one of the best manufacturer in Asia! The reality can prove it !