£ <span style=" color: #151616;">*They must wet the contact surface well; after the sliding operation the lubrication film must close itself again, i.e. mechanical interruptions to heal</span></p><p class="s6">£ <span style=" color: #151616;">*They should not transform into resins, not evaporate, and not act as dust collectors</span></p><p class="s6">£ <span style=" color: #151616;">*The lubricants should not dissolve plastics, they should not</span></p><p>be corrosive to non-precious metals or initiate cracking through stress corrosion of plastic components</p><p class="s6">£ <span style=" color: #151616;">*The specific electrical resistance of the lubricants cannot be so low that wetted plastic surfaces lose their isolating properties</span></p><p class="s6">£ <span style=" color: #151616;">*The lubricant layer should not increase the contact resistance; the wear reducing properties of the lubricant film should keep the contact resistance low and consistent over the longest possible operation time Solid lubricants include for example 0.05 – 0.2 μm thin hard gold layers whichare added as surface layers on top of the actual contact material. Among the various contact lubricants offered on the market contact lubricationoils have shown performance advantages. They are mostly synthetic,