Time, dirt and debris all work to make a deadbolt lock stiffen up and not open as easily as it once did. If left unfixed, you can be in danger of breaking your key off in the lock, requiring a replacement and possibly a call to a locksmith. If your lock is stiff and becoming increasingly hard to turn, it is time to lubricate your deadbolt lock. Lubricating the lock is simple for anyone to do and only requires a trip to the hardware store to purchase the proper lubricants.
Squeeze graphite powder directly into the keyhole two to three times. If the lock has keyholes on both sides, spray both sides. Otherwise, spray around the thumb latch on the opposite side.
Place key into keyhole and turn to lock and unlock several times. Repeat for the other keyhole or turn the lever several times to distribute the graphite.
Open the door and lock the bolt so that it is protruding from the door. Coat completely in graphite powder and lock and unlock it several times to distribute the graphite.
Wipe away any excess graphite powder from the lock, bolt and key. Repeat the process whenever the deadbolt begins to stick again.