Door hinge oil (machine oil)
What lubricant to use to silence squeaking door hinges : Door Hinge Oil (machine Oil)
Quote from Article entitled What lubricant to use to silence squeaking door hinges:
To lubricate a lock, the keyhole must be pre-treated with a cleaner: pour it inside the keyhole and turn the key several times. After the cleaning, some lubricant should be poured into the keyhole, the most convenient way to do it is to use a pump-action spray equipped with a thin plastic tube.
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