Important Notice About Jimmy Proof Locks (Rim Cylinder Type)

We’ve identified a common issue with Canstar, Maxtech, Northstar, USstar, Kenaurd, and other Mul-T-Lock–style look-alike Jimmy Proof locks that use rim cylinders.

Most jimmy proof locks produced since the 2000s are manufactured with brass internal components. These parts tend to wear and break over time, which can cause:

• The outside rim cylinder to spin freely (turn empty)

• Complete lock failure on both security and standard rim cylinder installations

Clarification on brands and quality

• HALCO and ILCO jimmy proof locks break frequently due to weaker internal mechanisms

• Yale produces higher-quality jimmy proof locks, but they are more expensive than standard options

Root cause of the problem

The issue is not with the rim cylinder or key section on the outside of the door.

The failure comes from the internal locking mechanism inside the door.

When a door is misaligned, users often need to pull or push the door for the pin to drop into the striker. If the pin does not drop cleanly, the mechanism binds. Over time, customers force the lock to engage, which leads to internal breakage and eventual cylinder failure.

How to prevent lock damage

To avoid premature lock failure:

• ✅ Ensure the door and lock are perfectly aligned

• ✅ The pin must drop into the striker without any pressure on the door

• ❌ Do not force the lock if it feels tight or stuck

Correct alignment every time is essential to protect the internal mechanism and extend the life of the lock.

Call us 514-836-9097 or by email: info@serruriermontreal.com