Explanation of Lock Grades – Grade 1 is Best

To save you the time, I will put the relevant information here – the best deadbolt locks are Grade 1, and really only cost a few dollars more, about $5 difference between Grade 1 and Grade 3. The added security outweighs the additional cost and should be a pretty easy decision. If you would like to know more keep reading.

Door locks get graded based on a specific set of criteria that is accepted industry wide. The handle or lever of a lockset is graded using the same system, however the important part of the lockset is the deadbolt. The deadbolt is the part of your lockset that deters a break-in. There are minimum requirements that the deadbolts must meet to achieve the ranking

These grades were developed by Builders Hardware Manufacturers Association (BHMA) for the American National Standards Institute (ANSI). When shopping for locks you might see “ANSI Grade” or “BHMA Grade” or even “ANSI/BHMA Grade”. ANSI or BHMA use the same grading system. One of the industry leaders in residential locks, Kwikset, provides good information on grading.

Grade 1 locks are usually used in commercial buildings but are starting to be made for residential use. These locks are made with stronger materials to hinder being drilled into and to withstand 1 million uses without failure and to withstand being struck with 75 pounds 10 times. Grade 1 locks have a 1″ latch bolt to set the bolt further into the door frame.

Grade 2 and 3 locks are usually used on residential entry doors. These locks are made to withstand 800,000 uses without failure. Grade 2 locks withstand being struck with 75 pounds 5 times, whereas Grade 3 locks withstand 75 pounds being struck 2 times. Grade 2 and Grade 3 locks have a 5/8″ diameter latch bolt, 3/8″ less than the Grade 1 bolt.

For the most secure deadbolts you should, if possible, get a Grade 1 deadbolt. These are more expensive than Grade 2 or Grade 3 but with proper installation will provide the most benefit. Most deadbolts come with screws only long enough for the strike plate to be screwed in to the door frame, this is not a secure installation. The strike plate for the deadbolt should be screwed into the adjacent wood stud.

Most door frames are, at most, 1″ thick and easily damaged during a break-in attempt. However, the 2×4 that the door frame is attached to is much harder to damage and break because it is 1 1/2″ thick and attached to the 2×4 running horizontally at the top of the door frame. Your local home improvement stores will carry 3″ screws that can be used for this.


Author: Bill

6 thoughts on “Explanation of Lock Grades – Grade 1 is Best

  1. Such an interesting article.. I personally don’t know what Grade of locks I’m using for my front door, but now I seem to be really interested and would really like to install the best of the best..  is there anyway to check for the grade of locks I am using?

    1. Hi Solomon. The easiest way to tell would be to measure the diameter of the bolt. If it measures 5/8″ it is not Grade 1. The Schlage deadbolt has a ridge at the base of the housing if it is Grade 1. If the housing is smooth with no lip then it is Grade 3. The Kwikset deadbolt is pretty much the same with ridges on the Grade 1 and smooth on Grade 3. But the diameter of the bolt is the best way to find out.

  2. Hi Bill! Thank you very much for your post! It has opened my eyes on very basic stuff that I had no idea about. I started researching what BHMA meant. And then I also came across ANSI grades. And now I found your post that has given me just what I needed concerning door locks. I’m grateful. 

    Plus, I like the practical suggestion of always choosing Grade 1 considering the added security outweighs the additional cost.

  3. I have to check what door knob I have now, I live in an apartment complex, so I don’t think they’d want me changing the whole door knob but it wouldn’t hurt as long as I’m living here I think. I certainly don’t want anyone breaking into my home, it’s an enclosed apartment complex, very small and gated on both entry ways to it. One night my bike was out there, locked up and I woke up and it was cut and my bike was gone. So crime is definitely alive here for sure. What door locks do you recommend?

    1. Hi Nate, good question. I really recommend anything that is Grade 1. There should be no issues with retrofitting the door, meaning the current holes in the door should match whatever lock you get. But before you go changing the lock you might want to check your lease agreement. A lot of apartments don’t want you changing out the locks without at least running it by them first. 

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