What ANSI/BHMA Grades Mean for Smart Locks

“ANSI Grade 1” is the most-quoted specification in door hardware and one of the least understood. The confusion is not the buyer's fault: there are two grading systems in use, they look like they should map onto each other, and the trade press publishes conflicting numbers for both. This page sorts out what is actually published, and says clearly where we will not print a figure.

System one: Grade 1, 2 and 3

These come from the commercial-lineage standards, and for a deadbolt the relevant one is ANSI/BHMA A156.36, Auxiliary Locks. BHMA's own description of its scope is that the standard “establishes requirements for Auxiliary Locks” and “includes dimensional criteria and five classifications of tests: operational, cycle, strength, security and finish.”

The grading rule is stricter than most people assume, and it is worth quoting because it is the part that gets lost. The standard says manufacturers shall indicate the grade level to which their product is certified, that products shall meet all grade requirements for the listed tests, and that “a Grade 1 product shall meet all Grade 1 criteria, a Grade 2 product shall meet all Grade 2 criteria, and a Grade 3 product shall meet all Grade 3 criteria in each classification.”

In other words a grade is not an average. A lock cannot be strong but short-lived and still be Grade 1; it has to clear the Grade 1 bar in operational, cycle, strength, security and finish. Roughly, Grade 1 is the commercial-duty tier, Grade 2 is the tier most residential front doors are specified at, and Grade 3 is the lightest.

System two: the residential letters, up to AAA

In the 2010s BHMA published a separate residential family of standards so that house hardware was not being judged against commercial-duty criteria: ANSI/BHMA A156.39, Residential Locksets & Latches and ANSI/BHMA A156.40, Residential Deadbolts. These grade a product in three categories — security, durability and finish — on a letter scale where A is the highest. A lock marked AAA has earned the top letter in all three. Certified products carry BHMA's Certified Secure Home label on the retail packaging.

Two consequences worth holding onto. First, because the three categories are graded separately, you can shop on the one you care about: a lock that is A for security and B for finish is a perfectly rational buy for a front door, and a better buy than paying for a finish grade you will never notice. Second, the residential letters do not convert into the numeric grades. An A in residential security is not “the same as” Grade 1, and anyone telling you the exchange rate is guessing.

The part that matters most for a smart lock

Neither system tests the smart half. Both are door-hardware standards: they test the bolt, the cylinder, the housing, the finish and the mechanical cycles. There is no grade in either system for the strength of the Wi-Fi pairing, the quality of the manufacturer's cloud, whether the app has had a disclosed breach, how a keypad resists someone reading the worn digits, or what happens to the lock when the vendor stops supporting it.

That is not a criticism of the standards — they are doing the job they were written for — but it changes how you should read a box. A Grade 1 or AAA smart lock is a well-made piece of door hardware with electronics attached, and the electronics are ungraded. The digital side has to be assessed separately, and we do that in our smart lock safety guide and, sorted by where an attacker has to be standing, in our protocol risk guide.

How to check whether a grade claim is real

This is the practical skill this page exists to teach, and it takes about a minute.

1. Look for the standard number, not just the grade. “ANSI/BHMA A156.40 Grade AAA” is a checkable claim. “Grade 1 security” on its own, with no standard named, is marketing copy.
2. Check BHMA's Certified Products Directory. BHMA publishes a directory of certified products, and a product that is not listed in it is not certified under the program — whatever the box says. Certification is voluntary and requires independent laboratory testing; manufacturers do not have to be BHMA members to do it.
3. Check the exact model, not the product line. Brands certify specific SKUs. A grade earned by the mechanical version of a lock does not automatically transfer to the smart version of it, because the housing and the internals differ.
4. Treat silence as information. A manufacturer that has paid for certification advertises it. When a listing references standards bodies in general terms without naming a grade — which several smart lock brands do — the honest reading is that there is no grade to quote.

Why most smart locks carry no grade

Three reasons, and none of them is a conspiracy. Certification costs money per model and smart lock lines turn over fast, so a brand shipping a new model every eighteen months has less incentive to certify than one selling the same deadbolt for a decade. Many of the cheapest keyless locks are made by small brands on shared platforms, where nobody in the chain is paying for independent lab testing. And the newest designs — retrofits that clamp over an existing thumbturn, locks for sliding patio doors — are not the product the standards were written around, so there is often no applicable grade at all.

That last case is the honest one to understand. A retrofit lock is a motor attached to somebody else's deadbolt: whatever grade applies belongs to the deadbolt underneath, not to the motor. If a published grade is important to you, a retrofit cannot give you one, and the field is in our no-drilling roundup with that stated. Sliding patio door locks are the same story and worse — the mortise cases they fit have no equivalent residential grade, which our sliding door roundup says explicitly rather than implying one.

How much should a grade move your decision?

Less than the frame does, and this is the part no hardware brand will tell you. A Grade 1 deadbolt bolted into a jamb held by three half-inch screws fails at the jamb, exactly like a Grade 3 one — the grade describes the lock, and the failure is in the woodwork. Fix that first; it is ten minutes and a box of long screws, and it is laid out in our front door guide.

After that, a published grade is a genuine signal and worth paying something for, because it means an independent lab tested the thing and the brand was confident enough to publish the result. Just hold it in proportion: it tells you about the metal. It tells you nothing about whether the app will still exist in 2031.