Double Cylinder Door Locks

Double Cylinder Locks: How They Work and Types

This type of lock has two cylinders and require a key for locking and unlocking the exterior of the door. Unlike a single cylinder lock, there is no thumb-turn mechanism. The main reason for installing double cylinder locks is enhanced security. That’s because doors with adjacent windows or glass panels can be broken, allowing intruders to reach inside and unlock the door manually. Without a thumb-turn mechanism, intruders cannot do this. Double cylinder locks are an extra layer of protection for home and business security. Commercially, they’re often used in school classrooms, hospitals and high-risk businesses.

Determining Quality and Security of Double Cylinder Locks

There are four main things to consider when purchasing and installing double cylinder locks. Those factors include the American Nation Standards Institute (ANSI) grade, UL listing, function and key control. The ANSI grading system factors in toughness, latch length and longevity. The highest grade is 1, and the lowest grade is 3.

Grade 1 is often used for commercial applications. It can withstand 1 million cycles, and 10 strikes of 75 pounds.

Grade 2 is typically use for residential applications and can withstand 800,000 cycles and five strikes of 75 pounds of force.

Grade 3 double cylinder locks are generally used as an additional security measure on a door. While it can withstand 800,000 cycles, it can only withstand two strikes with 75 pounds of force.

With double cylinder lock styles, you can get Mul-T-Lock deadbolts for extra door protection through key control. These deadbolts come with a unique key card and duplicate keys, which can only be made when the key card is presented. For example, the Kwikset Signature Series 980 deadbolt with SmartKey Re-Key technology meets UL standards and is one of the toughest locks to pick.

Double Cylinder Lock Manufacturers

In addition to Kwikset, Medeco and Sargent are leading manufacturers of quality double cylinder locks. The Medeco Maxum residential deadbolt actually exceeds the ANSI grade 1. It’s highly resistant to hammering and prying with its hardened steel inserts and rotating pins. Its hardened steel bolt in heavy gauge steel provides maximum protection from physical attack. And it comes with locking technology to protect against unauthorized duplication. Even find it in many styles and finishes to suit your personal preference.

Sargent deadbolts are engineered and built with high-quality components to provide maximum security, performance and durability. Many of its locked are offered as single cylinder or double cylinder. The Sargent 8222-26D Double Cylinder Deadbolt can be keyed from either side to operate the deadbolt and is made of 12-gauge heavy duty steel. It’s important to note that double cylinder locks can be purchased both with or without a deadbolt.

Features of a Secure Double Cylinder Deadbolt Lock

Whether a lock is single cylinder or double cylinder, there are should-be factors to make it secure. The bolt should be constructed of hardened steel and extend to a minimum of one inch in diameter. Its collar should be properly tapered and be free spinning to make it difficult to grip. Its connecting screw should also be made of solid steel and be on the inside with no exposed screw heads. The connecting screws should also be a minimum of ¼ inch in diameter and go into a solid metal shock. While double cylinder locks add more protection, there is one drawback. In case of an emergency, such as a fire, you’ll have to have the key nearby.

It should be noted that no lock is 100% guaranteed to protect your home or business from intruders. However, you can lower the risk of a break-in by using double cylinder locks and deadbolt locks. And with today’s key technology, you can prevent a bump key break-in.

Learn about a growing security risk for homeowners with cylinder locks: Lock Bumping.

Reliable Residential & Commercial Locksmith Services

If you’re seeking to secure your residence or commercial business, turn to the locksmith experts at Great Valley Lockshop, located in Chester County, PA. We provide locksmith services to Malvern and surrounding communities. Our services include 24-hour locksmith services, security lock installation, electronic access control, repair and the installation of double cylinder locks and deadbolts. Since 1973, we have been the go-to locksmith for homes and commercial companies. We open the door to security. Give us a call today at 610-644-5334 or request a quote online and enhance the security of your home or facility.

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