We evaluated the six most commonly installed door lock types we encounter across New Jersey door repair calls — from older cylindrical knob locks in 1960s Bergen County colonials to modern Grade 1 deadbolts in new Ocean County construction. Two of the six can be bypassed in under 10 seconds by anyone with basic knowledge. Both are still common in NJ homes.
The Two That Fail the Security Test
Budget Cylindrical Knob Locks (Grade 3)
The most common lock on interior and sometimes exterior doors in older New Jersey homes. Grade 3 cylindrical knob locks have thin mounting bolts, cheap locking mechanisms, and can often be bypassed by applying lateral torque to the knob or by credit-card shimming. We do not install Grade 3 hardware on any exterior door in New Jersey and always flag existing Grade 3 installations on entry doors as a security issue during door repair calls.
Old-Style Chain Locks Without a Deadbolt
Chain locks were standard secondary security in older NJ construction — particularly pre-1970 apartments and townhouses in Hudson and Union counties. A chain lock without a deadbolt provides almost no resistance to a forced entry. The chain itself is typically the weakest point, not the mounting hardware. If this is your only secondary lock, a deadbolt installation is the right upgrade.
What We Recommend for NJ Homes
For exterior door security in New Jersey: a Grade 1 ANSI-rated deadbolt as the primary lock, with a Grade 2 or higher knob or lever set as a secondary. Grade 1 deadbolts have hardened steel bolts, anti-pick and anti-drill features, and are designed to resist the most common bypass methods. The cost difference between Grade 3 hardware (what many NJ homes have) and Grade 1 is typically $30–$60 in parts plus installation.