A graded seal and/or hermetic seal is used to overcome the difference in coefficients of thermal expansion. This is done by using a series of intermediate sealing glasses between the two different glasses on each end. The linear coefficient of expansion must be close to avoid these seals from cracking. Using special and unique techniques, Glass Dynamics LLC provides a wide range of graded seal products suited to applications in scientific, analytical and military industries with a highly skilled team of glassblowers, state of the art tools and machinery. For custom quotation and engineering support with absolute individual service please contact firstname.lastname@example.org.