Hardware Grades
- Locks are available in different grades, which relate to their construction and durability. These grades are a measure of application suitability. Most commercial applications require either Grade 1 or Grade 2 locking products. Because security, protection from vandalism, durability under heavy usage and other considerations are important, the greater strength of Grade 1 locks makes them the suitable choice for demanding applications. Grade 2 products are adequate for lighter duty, such as storage closets or doors where security is less of an issue than simply excluding people in general. They will keep people from walking through a door, but they provide much less protection against deliberate force than Grade 1 products.
- ANSI/NHMA standards, monitored by independent testing laboratories, separate Grade 1 from Grade 2. Typically, Grade 1 locks must meet twice the requirements of Grade 2. In cycle tests for example, a Grade 2 lock need only function for 400,000 cycles, while a Grade 1 lock must meet at least 800,000 cycles. Some manufacturers regularly test beyond that limit into the millions of cycles.
- Even among locks promoted as Grade 1, there can be some differences. For mortise locks, ANSI A156.13 makes distinctions between Grade 1 Operational and Grade 1 Security. The section includes a distinct operational test that encompasses everything from cycling to finish testing of mortise locks. A separate listing covers security grading.
- For most other types of locks, both security and operational aspects are included under a single grade. ANSI A156.2 Series 4000 is the standard for bored-in locks and latches. While only an operational grade, it includes some considerations such as lock lever torque, vertical impact load on the knob or lever, and other destructive tests. Because the cylinder projects from the door, it is more vulnerable to attack than a mortise lock and is not really considered a security item.
- Unlike some other hardware, which is available in listed and non-listed versions, most commercial locks are UL fire-listed. Most manufacturers have different latch bolt lengths available and have listed them so they can be used on both fire-rated and non-fire-rated doors. However, different products are listed with different sizes of door, depending on such variables as latch type and size. When used in a fire-rated application, each product should be checked in the UL Building Materials Directory to see what its listing actually covers.
Hardware Info
