First of all we are a factory authorized distributor of body armor, so we know the products. SAPI plates, (small arms protective inserts) or rifle plates, or ballistic inserts as they are also known are armor plates inserted into a carrier or body armor to increase the protection level (bullet stopping) of the vest. They are made of soft ballistics, which are unable to provide protection above level IIIa ( 44 magnum handgun), steel (or steel and fabrics) and ceramic and fabrics, which can provide protection as high as level IV (high powered rifle armor piercing rounds).

Fabric and steel inserts will stand up to about anything and keep protection for years. Ceramic inserts are actually fragile ! Especially the older ones and military SAPI plates. So if you are buying a used ceramic plate inspect it carefully or ask questions! If a ceramic plate is dropped or hit hard by an object (other than a bullet) it can crack, and if cracked, it  WILL NOT  provide the protection rated. If it has been shot by ANY caliber of bullet, even if multi hit rated DO NOT buy it. NIJ rates multi hit by shooting up to 6 rounds evenly spaced around the plate. Another round in the same place can go through. Ceramic works because it is so hard, almost as hard as diamond, but it is brittle. So ceramic plates are surrounded by ballistic fabric (kevlar, goldflex, spectra, spectrashield, or HDPE). The bullet is actually broken into small pieces when it hits the ceramic. The fabric serves 2 purposes, to protect the ceramic under normal conditions, and to catch bullet fragments when under fire.

But it is easy to tell if a plate is damaged. A cracked plate will rattle or crunch, sounding like a broken dish, or will noticable bend if you apply pressure. An undamaged ceramic plate will not bend. So be informed if buying used plates.

The newest plates made of alumina, silicon carbide or boron carbide ceramic, and HDPE hold up very well to bumps and bangs and offer better protection and lighter weight.

One final point. The US Dept. of Defense says that ANY plate marked US is considered stolen because none have ever been released as surplus.