In the last few years we have been pressed to find ways to get lead out of the plunge grind finish on seal diameters of shafts that we manufacture. OEM’s like Ford and Nissan are constantly pushing for more control on the surface finish and proof that there is not any lead. For the last 60 years or so the “String Test” has been the universally accepted standard of checking for lead. As you can see by the picture, we still use that method today. There are some new checking instruments that can digitally recognize whether or not there is lead, but they basically confirm what the sting test is showing us already. We have even spoken to some suppliers that have found ways to hard turn a seal surface with carbide inserts and not have lead in it! We are looking into that option now. For more information email us at [email protected] or Read more