Grade 1 vs Grade 2 locks: choosing a commercial lever lock

This section and those after it, unless dated otherwise, were checked on 1 October 2026 against the sources listed on this page.

A Grade 1 lock has passed the highest level of testing in ANSI/BHMA A156.2, the American National Standard for bored and preassembled locks and latches, and a Grade 2 lock has passed the level below it. BHMA, which maintains the standard, states the Grade 1 durability test as one million open-and-close cycles with a 10 lb axial load.

Grades run from 1 to 3, Grade 1 the highest, and a lock must meet every criterion of the grade its maker states. BHMA’s public summary of the 2022 edition gives only the Grade 1 cycle figure; the Grade 2 and 3 thresholds are in the full standard, which BHMA sells. What the summary says is tested:

The tests run under laboratory conditions, and results in use vary with installation, door and frame construction, maintenance and environment (A156.2-2017 section 1.2, as BHMA publishes it). A grade also belongs to its standard: BHMA certifies mortise locks (A156.13), residential locksets (A156.39) and residential deadbolts (A156.40) under separate standards, so a cycle count quoted for a home deadbolt is not an A156.2 figure.

Check a lock’s grade in the maker’s catalog and in BHMA’s Certified Products Directory, not on the box alone. A catalog states the listing in full, as BEST’s does for the 9K: “Listed by BHMA for A156.2, Series 4000, Grade 1.” The directory lists products whose compliance with the standard was verified by independent third-party laboratories.

Certification is voluntary: the maker submits the product for independent laboratory testing, BHMA coordinates periodic in-factory audits, and a product that cannot pass the audit faces loss of certification.

The grade is not a fire rating. BHMA says fire door hardware is evaluated and listed to UL 10C by an accredited third-party laboratory, separately from the grade: BEST’s Grade 2 7KC and Grade 1 9K are both UL listed for 3-hour A label doors, the 7KC for single doors up to 4 x 8 ft, the 9K for single doors up to 4 x 10 ft and pairs up to 8 ft wide and 10 ft high.

We supply listed hardware and confirm in writing the part number and options you have chosen. We are not code consultants; your Authority Having Jurisdiction (AHJ) makes the final call.

A replacement lock has to match the door prep because the holes are already cut and its parts meet inside them. In BEST’s instructions the chassis goes into the 2-1/8 in bore from outside to meet the latch, whose tabs engage the chassis frame and whose tailpiece engages the retractor, and BEST makes a separate latch for each backset.

What else to check on the door and frame, with BEST’s figures:

BEST also cautions that a hollow metal door must be reinforced enough to hold the lock, and that the latch’s deadlocking plunger must not enter the strike opening: a gap of more than 1/8 in may reduce security or make the latchbolt operate improperly.