Does Ceramic Armor Expire? A Look at How Long Body Armor Lasts
When it comes to ceramic body armor, there's often speculation on its shelf life and what is inferred by the manufacturer. Here we will clear the air on any confusion and help you better understand the shelf life of ceramic body armor.
Does Ceramic Armor Expire?
Generally, properly made and maintained ceramic body armor does NOT expire. High quality plates, and the materials used within them, do not have a physical expiration date. What is meant by the "expiration date" found on the back of plates is the manufacturer's warranty expiration. This is usually a time period ranging from five to ten years. This is simply the time frame in which the manufacturer guarantees the plate's performance, notably for liability purposes.
This does not necessarily mean the plate is expired and no longer works. These time frames generally take into consideration the likelihood of normal wear and tear over time and the degree to which it can compromise performance. However, if your plate doesn't experience anything severe or structurally damaging like repeated drops, excess soaking, or of course a bullet, it can last beyond the warranty period. It is important to note for those in settings where body armor is routinely required like military, law enforcement, security, etc., it is strongly advised that armor be replaced past warranty.
Do Materials Degrade or Lose Strength?
When properly manufactured and maintained, the ceramic and the surrounding layers, whether it be PE or Aramid, does not expire nor degrade to any degree which would compromise performance. What is more important is the quality of bonding of all these materials, specifically the bonding of the strike face to the plate backer.
Ceramics are bonded to backers often using glue or a heat press process, and then covered in a waterproof fabric such as nylon. The quality of this process is a large factor of the plate's overall quality and ability to last. High quality manufacturers like LTC and HighCom use a heat press process which is objectively better in securing and holding the plate together. Military and law enforcement chooses ceramic armor manufacturers like LTC, HighCom, TenCate, and Ceradyne for their superior manufacturing quality. This process creates less possibilities for moisture absorption and the strongest hold at rest and in use. Cheaply made ceramic plates use glued backers that degrade and separate overtime, compromising performance. They are also poorly sealed, letting the plate absorb moisture and degrading the inner materials.
While obtaining high quality ceramics is a great start, it is important to properly maintain your gear to maximize its potential. When not in use, plates should be kept in a dry, room-temperature environment. This setting prevents moisture absorption and preserves the integrity of the plate. To check for degradation and delamination (separation of the backer from the strike face) you can perform two quick and commonly known tests known as the tap test and torque test.
The Tap and Torque Tests
The tap test is a quick check-up on the lamination of the plate's backer to its strike face.
The test involves tapping the backside of the plate and listening for one of two sounds: A chime or a thud. A chime or ringing sound is good and indicates the plate is intact. A thud is bad and might suggest there are possible delamination issues.
To perform the test, obtain a solid metal object like a screwdriver or pocket knife and position the plate with the back side facing up. The military uses a specifically issued tap test tool, but for civilians, any small and solid metal object will do. Tap the outside edges of the plate about two inches apart, working around the plate and inward until you get to the center. However, there is no need to tap the center most part of the plate. The center of the plate has the most surrounding material and will always make a thud sound, even though the plate is perfectly fine. Do not tap on labels as these are also spots of excess material and will prohibit proper sound feedback.
The torque test is even simpler. Grab two opposite corners of the plate (i.e. the top left and bottom right), and twist the plate. Repeat with the other corners. Then position the plate face down, against your body, and begin pressing and feeling the outer edges. If you hear any crumbling or rattling on any part of the test, this can signify potential cracks in the ceramic.
Here's a clip to show how tap and torque tests are conducted by the military on ESAPI plates:
Wrapping Things Up
Now you should have a better grasp on how long your ceramic plates are actually made to last and what is meant by the expiration date on them. Keep good care of your armor and make sure to periodically check on your armor using the tests we've previously discussed here. Remember, if you are active military, law enforcement, or work in any setting where body armor is routinely required, it is strongly encouraged to replace your armor past warranty.