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How to Open a Circle Lock

Brad Chacos

Keys and locks come in many sizes and shapes other than the standard door lock. Known by the term "circle lock" because of the shape of its key, a tubular lock uses a high-security pin and tumbler locking system that employs a special key shaped like a fat, hollow tube. The key sports several cuts, or "bittings,"

carved into the end of the tube at different locations and depths to align with the pins in the lock. If you lose your key, a tubular lock pick can help you open the lock and identify needle depths for a new key.

  1. Using a tubular lock pick, unscrew the tension on the large, textured o-ring. Place your fingers between the movable circular washer and the rubber handle. Slide the washer along the handle of the pick, pushing the spiky needle array directly against the o-ring collars until the tips of the picking needles protrude from the end of the pick. Push the end of the pick against a flat surface to align the picking needles with the end of the pick, then re-tighten the tension on the textured o-ring. Be careful not to overly tighten the o-ring to a point where the picking needles will not move in the lock.

  2. Align the guide-notch on the lock's diameter with the small, matching barrel inside the end of the pick. Slide the pick into the lock. Continue until you touch the rear wall of the lock and can't push any further.

  3. Gently rotate the pick left and right, using slow, deliberate motions. Very slowly pull the pick out of the lock while doing so, keeping the pick perpendicular to the lock at all times. Continue until the lock opens.

  4. Slide the pick out of the opened lock. Turn the large, textured o-ring to the right to tighten the tension on the picking needles, locking their depth in place. Measure the depth of each picking needle using the decoder key provided with the pick. Use the measurements to create a new key.