Servicing Medeco³ BiLevel

As a locksmith professional, you no doubt have had customers who have needed the protection of high security lock cylinders on some doors, but not on their entire facility. Often times the exterior doors need the protection of a UL437 cylinder, but using the same high security cylinder on an interior stairwell door might be considered overkill. The newly released Medeco³ BiLevel line of cylinders offers a solution to this dilemma by providing the ability to key alike non-UL437 and UL437 listed high security cylinders.

Let us start by taking a closer look at the BiLevel cylinder components and how they differ from Medeco's high security cylinders. (Numbers correspond to photo 1)

1. The BiLevel cylinder's plug is the same high quality, all brass machined construction as its Medeco³ cousin, without any hardened steel drill-resistant inserts. The plugs are available in all existing Medeco³ keyways.

2. The BiLevel slider mechanism is the same dimensionally as the Medeco³ slider, but is made of zinc.

3. The BiLevel sidebar differs significantly from the one found in the Medeco³ cylinder. Made of zinc, it has no sidebar legs, and no hardened steel drill resistant ball-bearing insert.

4. Like the plug, the BiLevel shell is machined brass. There are no millings in the plug face for hardened steel crescents. The shell also carries the M3B BiLevel logo so it can be easily identified as such. Since the cylinders are not UL listed, there is no UL437 logo.

5. Unlike the chisel-pointed pins found in the Medeco³ high security cylinders, BiLevel bottom pins are conical. BiLevel pins are made of brass and plated with nickel silver for durability.

6. The BiLevel plugs, and shells have no locator tab slots, which means their parts cannot be interchanged with Medeco³ high security cylinders.

BiLevel cylinders operate much like a standard pin tumbler lock, with the addition of a slider and legless sidebar for additional protection against picking, key interchange, and increased master keying capability. BiLevel products are available in all current Medeco³ keyways, and can only use Medeco³ keys. In other words, there are no BiLevel-specific key blanks or cut keys. Since the Medeco³ keys used to operate BiLevel cylinders must also operate Medeco³ cylinders, the keys will have angled cuts. However, BiLevel uses the cut depths to reach the plug shear line, and the side milling on the key to engage slider mechanism.

The keys used in a BiLevel application must be cut using all aft position cuts in order for the spacing to be correct in the BiLevel cylinder. Because of this fact, master key systems and individual key codes must be specifically ordered for the BiLevel application. Existing Medeco³ master key systems (that do not use all aft position cuts) and key codes are not compatible with BiLevel's all-aft position requirement.

A thicker head on the BiLevel plug does not allow the Medeco³ cut key to enter as far into the BiLevel plug as it does a Medeco³ plug. This allows the aft position cuts on the key to line up with the center of the pin chamber holes in a BiLevel cylinder, and in the aft position in the Medeco³ cylinder. The shoulder-to-first-cut spacing for a Medeco³ key cut to operate BiLevel cylinder is .275. Cut-to-cut spacing is .170.

BiLevel and Medeco³ bottom pins share the same .025 pinning increment and brass construction, but are otherwise completely different. The most obvious distinction lies in the shape; Medeco³ bottom pin tips are chisel-pointed and BiLevel pin tips are conical.

BiLevel pins are nickel plated for durability just like their Medeco³ brethren, and also oxidized to give them a unique color. This allows them to be easily distinguished from other common-looking bottom pins. BiLevel pins are also different in that they do not have a sidebar slot like their Medeco³ counterparts since they do not need to rotate.