Ed said "From: http://www.wd40.com/Brands/wd40_product_info.html "PENETRATES: WD-40 loosens rust-to-metal bonds and frees stuck, frozen or rusted metal parts." And I say, "Ain't advertising flacks wonderful". Designed as a "water displacer", it has gained repute in the mass marketplace as a penetrating oil, but it isn't a very good one. John