Understanding Lock Grades

Learn the differences between Grades 1, 2 and 3.


Grade 1 – Heavy Duty Commercial

The strongest and most secure locks in the industry, Grade 1 hardware is designed for commercial security applications and is ideal for high traffic (and potentially high abuse) environments including schools, hospitals, and commercial buildings and venues. Grade 1 hardware is recommended for exterior doors and entry points, as well as high-security and high-usage areas – restrooms, cash rooms, etc.

Grade 2 – Standard Duty Commercial

Grade 2 locks are recommended for commercial applications with standard traffic flow (less than 100 cycles a day), where forced entry is less of a risk. Many commercial office buildings use Grade 2 hardware for interior offices, exam rooms, and storage closets.

Grade 3 - Light Duty Commercial / Residential

While not the most highly rated, these locks still meet ANSI/BHMA’s stringent criteria and are generally sufficient for low-security, low-traffic interior applications.


Security hardware undergoes rigorous testing of operability, durability, safety & security, and aesthetics, as well as compliance with applicable building codes, accessibility requirements, and sustainability guidelines. Some of these standards are equivalent across the grades, establishing a minimum level of expected functionality, whereas other tests are used to determine the best products for a specific application.

(*All tests are specific to hardware classification, i.e. Grade 1 door closers are not submitted to the same tests at Grade 1 lock hardware)

All mortise lever locks (ANSI/BHMA A156.13), for instance, share a number of Operational, Strength, and Finish requirements:

  • Must retract when subjected to 28 inch-pounds or less rotational force
  • Must latch when subjected to 4.5 pounds of force or less
  • Must withstand 360 pounds applied to the top of the lever
  • Must continue to look acceptable after exposure to environmental conditions (salt, humidity, UV rays, etc)

But evaluation of the Cycle, Security, and Material Evaluation tests help confirm which grade is best suited to a particular opening:

Functionality Test Grade 1 Grade 2 Grade 3
Cycles (Mechanical operations) 1,000,000 800,000 800,000
Security (Using a ram to impact the cylinder face) 10 blows at 75 foot-pounds of force 5 blows at 75 foot-pounds of force 2 blows at 75 foot-pounds of force
Material evaluation (Using a pointed probe to impact the lock rose) 0.075 inch 0.100 inch 0.100 inch


Product grade levels for security hardware are determined by the Builders Hardware Manufacturers Association and the American National Standards Institute, and verified by independent laboratories.


Posted in: Product News & Info