ANSI/BHMA grades 1, 2, and 3
The Builders Hardware Manufacturers Association tests locks for durability, strength, and security under ANSI standards. Grade 1 is the highest, built for commercial doors; Grade 2 is solid residential; Grade 3 is entry-level. Many big-box locks are Grade 3.
What “high security” means
A high-security cylinder is listed to UL 437 or ANSI/BHMA 156.30, meaning it's been tested against picking, drilling, and forced attacks for a set time. Most also use restricted keys that can only be duplicated by an authorized dealer with your signature card. Medeco and ASSA are common examples.
Common attacks
- Picking: manipulating pins one at a time with tools. Defeated by security pins, sidebars, and rotating pins.
- Bumping: a specially cut key struck to bounce pins to the shear line. Defeated by bump-resistant pin designs and restricted keyways.
- Drilling: destroying the shear line with a drill. Defeated by hardened steel inserts in the cylinder and housing.
- Forced entry: kicking or prying the door. Defeated by strike plates with long screws, reinforced frames, and door guards — the lock is only as good as the door.
What we recommend
For most homes, a well-installed Grade 2 deadbolt with a reinforced strike is a big step up. For businesses, rentals with turnover, or anything holding cash, firearms, or medication, a UL 437 cylinder with restricted keys is worth it.
Common questions
What is the best lock grade for a home?
An ANSI/BHMA Grade 2 deadbolt with a reinforced strike plate is a strong choice for most homes. Grade 1 is commercial-duty.
Can high-security locks be bumped?
Cylinders listed to UL 437 are designed and tested to resist picking and bumping, and most use restricted keyways.
Why use restricted keys?
Restricted keys can only be duplicated by an authorized dealer for people on your authorization list, so you control every copy.