The CS700 (or CS712, OS711, Impregnable) is a lever cylinder high security padlock made by Ingersoll Security, using the Ingersoll "Impregnable" lever cylinder key mechanism. It uses ten levers and a spring-biased sidebar as the primary locking mechanisms. Levers are interspersed to act with a double-bitted key. The CS700 does not use a traditional style lever fence arrangement, and the key resembles a pin-tumbler or wafer style key. This is a double-sided key, not a 'convenience' key, and will only enter the lock one way. The CS700 is easily identifiable by the bulleted keyway that resembles a flattened "w".
The CS700 also comes in a six-lever model known as the OS600.
Principles of operation
The CS700 uses ten nickel-silver levers that alternate bitting surface in the plug. Each lever uses its own spring (similar to traditional lever locks) and pivots along a common rod located at 6 o'clock. There are four positions available for gate cuts on the edge of each lever, giving the CS700 a total of 1,048,576 (410) theoretical key differs. The only keying constraint is that a bitting depth should not be repeated more than three times sequentially. This gives the CS700 840 differs per bitting surface, for a total of 705,600 (8402) real key differs. The CS700 can be master keyed using widened true gates (gates that accommodate adjacent bittings), or with multiple true gates on each lever.
Keys are double-sided and nonsymmetric. Each bitting area interfaces with five of the levers. Keys are stamped with an indirect key bitting code and require a security card before they can be duplicated.
This key mechanism comes in a variety of models, including traditional mortise and rim deadlocks. There are different padlock models based on the type of shackle protection used, but the internal locking mechanism is identical:
- OS600: Fully exposed shackle, 6 lever version
- OS711: Fully exposed shackle
- CS712: Semi-exposed shackle
- CS700: Closed shackle
- Unlock the padlock with the correct key.
- Remove the retaining screw(s) from the shackle hole.
- Remove the plug from the padlock body.
The CS700 might be vulnerable to one or more of the following:
- The Impregnable key mechanism is not vulnerable to 'bumping'.
- The rubber ring around the plug helps dampen feedback from lockpicking tools.
- The OS600 (six lever version) was the topic of the Non-Destructive Entry magazine article Ingersoll Picking Tutorial by John Naughton.
- PULFORD, Graham (2007). High Security Mechanical Locks: An Encyclopedic Reference. ISBN 0750684372.
- Non-Destructive Entry Magazine (pdf). Volume 1, Issue 4. Naughton, John. Ingersoll Picking Tutorial .