What is the difference between grade 1 and grade 3 locks? (BHMA and ANSI explained)

Whether it is a residential or commercial lock, we should ask the question how good is this particular lock? If I pay money is it going to serve me for many years including protection from weather conditions or burglar activities? That’s why there is a quality standard and regulation in United Stated regarding lock quality which also helps contractors, builders, or anyone who needs to access rating

According to BHMA/ANSI there are three categorized grade systems. Grade 1 is the strongest and most durable lock that is considered heavy duty with the longest use cycles (up to 800K cycles and 450 lb/in strength when lock forced to turn), while grade 3 is the lowest and still widely used (up to 200K cycles and 180 lb/in strength when lock forced to turn) which is the most commonly installed lock in residential and some commercial doors that appropriate for delicate applications

The American National Standards Institute (ANSI) is a private, non-profit organization that administers and coordinates the U.S. voluntary standards and conformity assessment system. And BHMA is the official trade association for manufacturers of building hardware accredited by ANSI to enforce performance standards.

How to know what lock grade is right for you?

Let’s first understand what exactly all 3 grades mean and how they are measured. The strength of locks is measured using these categories: (it might be some other test we don’t know or publicly not available)

  • Strength test
  • Cycle test
  • Operational test
  • Security test
  • Finish test

The BHMA has its own rating system for locks. The ratings come in three categories: security, durability, and finish and are rated by the letters A, B, and C (which is trade association). While widely used ANSI institutes has from 1 to 3 grading.

Generally speaking, Grade 1 is a definitely better choice if there is sufficient budget for that, however, Grade 3 is reasonable enough as long as the lock is not pickable or hard to drill.


I am Rauan, I have over 4 years of experience as a locksmith tech and then as the owner of my own company. I live in Houston, TX, and love to provide valuable insights related to locks. Enjoy reading

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