How to lubricate entry doors and what to use : Graphite Powder
Quote from Article entitled How to lubricate entry doors and what to use:
Combination locks always have special holes for inserting a lubricant. Lubricants usually target the heart of the locking-mechanism while protecting it from dirt and corrosion. It is recommended to use such penetrating aerosols as WD-40, and so on and so forth.
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