A Comprehensive Guide to Lock Grades

Most people view the front door and its locking system as the first line of defense in home security. Therefore, choosing the right type of door hardware is essential to ensure that burglars and other unauthorized individuals do not gain access to your home.

In the United States, door hardware is tested and graded according to standards developed by the American National Standards Institute (ANSI) and the Builders Hardware Manufacturers Association (BHMA). Here’s what ANSI and BHMA lock grades mean and how to choose the best locks for your needs.

ANSI vs. BHMA Standards

Although the ANSI and the BHMA partnered to develop door hardware and lock security testing standards and grading systems, each organization has its own grading system for locking devices.

When choosing door hardware for your home’s entry points, it is essential to understand the difference between the two and what each grading system measures.

ANSI Standards and Lock Grades Explained

The ANSI standards for testing and evaluating the performance of various types of door hardware were developed in conjunction with the BHMA and listed in a document titled Series A156.

One of the most common lockset testing standards is ANSI/BHMA A156.2, which establishes a list of requirements for bored and preassembled locks and latches. Other commonly tested types of lock hardware include butt hinges (A156.1), mortise locks (A156.13), door controls (A156.4), and exit devices (A156.3).

ANSI lock grades

All locking hardware tested and approved by the ANSI may receive one of three possible classifications:

• Grade 1 - For heavy-duty commercial and high-security residential use
• Grade 2 - For medium-duty residential and commercial use
• Grade 3 - For light-duty residential use

The lower the grade, the more resistance it offers against abuse, impacts, picking, or bump-key attacks.

ANSI testing

When undergoing ANSI testing protocols, door locksets must undergo three critical tests: a cycle test, a strike impact resistance test, and a strength test.

The cycle test consists of repeated cycling of the door hardware’s functions, measuring wear and tear, and checking for loss of operational performance in the process. For example, a door lock cycle is one instance of locking and unlocking, whereas a door lever cycle would consist of pulling it and letting go.

ANSI cycle testing scores and grading for locking devices:

• Bored locks: Requires a minimum of 200,000 cycles for Grade 3 certification, 400,000 for Grade 2, and 1 million for Grade 1
• Mortise locks: Requires a minimum of 800,000 cycles for Grade 2 and 3 certification and 1 million for Grade 1

Strike impact resistance tests measure the lock’s ability to resist forced entry. Locks are tested by applying a ramming device to the cylinder face, developing approximately 75 foot-pounds-force of energy.

• Grade 3 certification: Resisted at least two impacts
• Grade 2 certification: Resisted at least five impacts
• Grade 1 certification: Resisted at least ten impacts

Strength tests measure whether the hardware can withstand daily abuse without losing functionality (e.g., applying too much force on a lever). A lock must withstand up to 360 lbs. of force to receive a passing certification in all three grades.

BHMA Secure Home Lock Grades

The BHMA employs a three-category grading system independent of the one used by the ANSI called the Secure Home BHMA Certified Label. The BHMA developed these standards in 2014 exclusively for testing residential door hardware, mainly because ANSI standards do not distinguish between residential and commercial hardware.

BHMA grading nomenclature

The three categories are as follows:

• Security: Measures the lockset’s ability to withstand excessive force and impacts, similar to the ANSI strength and strike impact resistance tests
• Durability: Measures the lockset’s ease of use throughout all seasons and after extensive use, similar to the ANSI cycle test, but also its resistance to denting and other light impacts
• Finish: Measure the lockset’s passive resistance to the elements, such as humidity, salt, or ultraviolet rays

Each category has three grades: C (good), B (better), and A (best). The specific order of each letter indicates the lockset’s performance in each category. For example, a lockset with a BAC grade means B in security, A in durability, and C in the finish category.

How to Choose the Right Lock Grades

The best way to choose door hardware is to consider their ANSI and BHMA grades before all other features.

Even if a particular product is brand-name or has the aesthetic features that best fit your house’s style and architecture, your door hardware must possess the durability and resilience to lock picking and brute-forcing that best match your needs.

While higher lock grades offer more security, the best choices for you are those that match your needs without far exceeding them. They will provide you with the security you need without over-spending.

ANSI Lock Grade Applications

The ANSI grading system is general-purpose, which applies to residential and commercial buildings. If you are looking for hardware for the front and back doors of a home or an apartment, a Grade 2 model is an excellent choice as the primary lock for most residential units, providing a suitable balance between price and security.

Grade 3 locks are best suited as secondary locks or in homes with relatively low-security requirements (e.g., countryside homes, low foot traffic). A Grade 1 lock is most suitable for commercial applications, although it may also help households with high-security needs.

BHMA Lock Grade Applications

The BHMA Secure Home grading system is intended exclusively for residential use on both exterior doors and interior doors.

Although the best possible grade a lockset can receive under this system is AAA (A in Security, A in Durability, A in Finish), it is critical to understand that you do not necessarily need AAA locks everywhere in your home.

Security rating (First letter)

Locksets at any entry points (front and back door) should prioritize security. Like the ANSI grades, match the grade to your local security needs.

A security B-grade lock fits most residential needs. If you need the maximum level of safety and security, select an A-grade lock. Avoid C-grade for entry points; this level is best suited for interior doors.

Durability rating (Second letter)

Match this grade to the number of occupants in the house because it implies more people will use (and therefore, wear out) the door in a year.

For example, C-grade may be all you need if you live alone or with a partner. If your household includes children, you may want to upgrade to a B-grade model. A-grades are ideal for large families or buildings with large numbers of frequent visitors.

Finish rating (Third letter)

Any exterior door should be B-grade at the minimum, as they are exposed to the elements and more frequent temperature changes.

If you live near the ocean or in relatively harsh climates, consider upgrading to a finish A-grade lock. Leave C-grades to interior doors unless they face frequent temperature or climate changes (e.g., a door between the garage and the house).

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