Locks come in different grades, indicating their level of trustworthiness for home and personal security. Grade one locks are the strongest and grade three locks the weakest. Prices increase proportionally to the strength of the lock grade, so tailor your purchase to your needs.
Grade one locks can withstand at least 1 million opening and closing cycles. Grades two and three are tested for up to 800,000 opening and closing cycles.
Grade one latch bolts project 3/4 of an inch from the door, and grade one deadbolts project 1 inch from the door. Grades two and three latch bolts project 1/2 inch, while grades two and three deadbolts project 5/8th of an inch.
Knob Impact Test
Grade one locks can withstand 10 blows of 75 foot-pounds to the knob. Grade two locks can withstand five blows of 75 ft-lbs. Grade three locks can withstand two blows of 75ft-lbs.
Bolt Impact Test
Grade one locks can withstand at least two blows from 60, 90, 120, or 150 ft-lbs. Grade two locks can withstand at least two blows from 60, 90, or 120 ft-lbs. Grade three locks can withstand at least two blows from 60 or 90 ft-lbs.
All grades of deadbolts can withstand at least five minutes of sawing and 600 lbs. of bolt-end pressure. All grades of latch bolts can withstand at least 360 lbs. of bolt-end pressure.
- Photo Credit lock image by Dwight Davis from Fotolia.com
What Kinds of Door Locks Cannot Be Picked?
Unfortunately, there really is no lock that cannot be picked. One of the best locks is a Grade 1 deadbolt. However, it...
What Are the Different Grades of Plywood?
Plywood comes in five grades: A, B, C, C plugged, and D. The grade refers to the appearance and strength of the...
What is a Grade 5 Machine Bolt?
When working with fasteners, it is a good idea to be familiar with the different types of fasteners, as well as the...
What Is a Grade 3 Deadbolt?
Grades for deadbolts are established by American National Standards Institute (ANSI) requirements. Grade 3 is recognized as the lowest passing standard, with...
What Do the Different Grades Mean for Hardwood and Plywood?
Whether you're remodeling old hardwood floors or planning a project with plywood or lumber, it's important to understand what grade of wood...
Why Is Grading Important On a Lockset?
Lockset grading is used to rate the security, quality and durability of individual lock models. In the United States, manufacturers rely on...