Wd 40 is an all purpose liquid for displacing moisture corrosion control lubrication cleaning and penetration it has the ability to penetrate the minute grain boundaries on all metals although not essentially a lubricant wd 40 is regularly used to lubricate all light machinery and electrical equipment wd 40 protects metal from rust and corrosion penetrates stuck or jammed parts displaces moisture and lubricates just about anything wd 40 is also great when it comes to cleaning grease grime and ot