Armor plates are worn in law enforcement, military and security work, and civilians ask about them too. Knowing what armor plates are made of helps a buyer read a product page: what the material affects, and what it does not decide.
Armor plates are meant to protect against ballistic threats, and the material affects weight, handling and what happens on impact. What a plate stops is something else: the level belongs to the exact model that was tested. This article sets out what the sources say about each material.
Understanding ballistic plates
Ballistic plates, often called armor plates or hard armor, are rigid plates worn in a plate carrier or vest. CJTTEC, which administers the NIJ Compliance Testing Program, says NIJ 0101.07 names its levels "HG" for handgun and "RF" for rifle, with "a reduction in soft-armor levels and an additional hard-armor protection level".
A plate can be listed as stand-alone, or as tested in conjunction with (ICW) a specific soft armor model, in which case the level belongs to the two together. CJTTEC says a plate should be used only with the specific soft armor model it was tested with: together they make an in-conjunction model. Plates come in various shapes and sizes; check the maker's stated dimensions for the exact model.
Not all ballistic plates are the same, and material is only part of the difference. NIJ tests and lists models, not materials: a ceramic, steel or polyethylene plate is listed at a level only if that model passed the test.
Stopping the round is not the whole test. Armor is tested against a clay backing, and the depth of the dent it leaves, the backface deformation, is measured against a maximum. NIJ 0101.06 sets the maximum at 44 mm, with a statistical allowance above it and an absolute limit of 50 mm, and NIJ Standard 0101.07 keeps the 44 mm limit. The dent stands in for the blunt load on the body; it is not a measurement of injury.
For how the levels compare, see Breaking Down Hard Body Armor Levels.
Ceramic armor plates
A ceramic rifle plate puts a very hard strike face in front of a fiber backing. The ceramic breaks up and blunts the round as it shatters, and the backing catches the fragments. Common armor ceramics include alumina, silicon carbide and boron carbide. In its 2011 report for the Army, the National Research Council describes silicon carbide and boron carbide as harder and lower in density than alumina, and alumina as widely used because its raw material costs less and it is easier to fabricate.
Ceramic is among the materials the National Research Council credits with reducing the weight of armor for personnel. CJTTEC advises against dropping ceramic plates on hard surfaces, which can cause breaks or cracks that can affect performance, and advises inspecting hard plates before each use.
On repeated hits, a level is earned against a defined shot pattern: named rounds, a set number of shots and set placement. Real-world multi-hit capacity beyond that pattern is not established by the test, for ceramic or any other material.
For how ceramic compares with steel, read Are Steel Plates Better Than Ceramic Plates?.
Metal armor plates
Metal armor plates are most often discussed as steel, and titanium alloys appear too. Steel is a dense metal. A 2009 study of steel-panel body armor (Egorov et al.) reports that fragments from a bullet striking hard steel, called spall, can ricochet and injure the wearer's arms, face or neck, and it tests layers mounted in front of the steel to contain them. Our advice: if you are considering steel, ask what fragment layer the plate has and how it was tested.
For titanium, the research we found is mostly about combat vehicles. Army Research Laboratory authors describe titanium alloys as offering high mass efficiency compared with steel armor and aluminum alloys, and an Army Research Laboratory report found that titanium's relatively high cost, with limited information on its ballistic properties, had kept it from wide use in ground vehicles. We found no NIJ, CJTTEC or NIST source on titanium body armor plates (checked 1 October 2026).
If you're considering a metal plate, the same rule applies as for any plate: the level is the model's. For what one rifle level is tested against, read What Does Level III Body Armor Protect Against?.
Plastic and polyethylene armor plates
Polyethylene plates are made from ultra-high-molecular-weight polyethylene (UHMWPE), pressed into a rigid plate. Research literature reports high energy absorption for UHMWPE for its weight, and the National Research Council counts polymers and polymer fibers among the materials that have reduced the weight of armor for personnel.
Heat is the limit the sources name. NIST has studied how heat in storage and use can reduce the strength of UHMWPE fibers. Our advice: follow the maker's storage and heat guidance for the exact model, and CJTTEC's advice to avoid extreme heat, such as a vehicle trunk.
For how levels and ratings are named, see Understanding Body Armor Ratings.
Comparing materials in armor plates
| Material | What a source says | What to check |
|---|---|---|
| Ceramic (alumina, silicon carbide, boron carbide) | Among the materials that have reduced armor weight (National Research Council). Do not drop on hard surfaces; breaks or cracks can affect performance (CJTTEC) | The model's listing; inspect before each use |
| Steel | A dense metal. Bullet fragments can ricochet off hard steel toward the wearer (Egorov et al., 2009) | The model's listing; the fragment layer and how it was tested |
| Titanium | Studied mostly for combat vehicles; cost and limited ballistic data limited its use there (Army Research Laboratory) | The model's listing; the maker's test report |
| Polyethylene (UHMWPE) | High energy absorption for its weight (research literature). Heat can reduce fiber strength (NIST) | The model's listing; the maker's storage and heat guidance |
Many plates combine materials, such as a ceramic strike face on a polyethylene or aramid backing. For the carrier side of the choice, see Exploring Different Types of Plate Carriers.
Pros and cons of different materials
We found no NIJ or CJTTEC source that ranks ceramic, steel or polyethylene on weight, cost, durability or multi-hit (checked 1 October 2026), so we do not. For a given plate, the answers live here:
| Question | Where the answer lives |
|---|---|
| Which level, under which standard | The model's CPL listing, with the date you read it, or the lab report for a plate outside the NIJ program |
| Stand-alone or ICW, and with which soft armor | The model's listing |
| Weight and thickness | The maker's stated figures for that exact model and size |
| Fragment layer (steel) | The maker's test report for that exact model |
| Storage and heat limits | The maker's care instructions |
| Price | Quotes for the exact model |
How to choose the right armor plate material
Start from the threats in your assessment, then the weight that can be worn for a full shift, and the conditions the plate will live in.
- Match the rounds in your threat assessment to a level whose test names those rounds.
- Check the exact model on the Compliant Products List (CPL), with the date you read its status. The CPL answers one question, whether the model met NIJ's program, and it matters where a buyer, policy or funder requires it. For a plate outside the program, ask for the standard and the lab report behind the claim, from a lab whose report can be validated.
- Check whether it is stand-alone or ICW, and with which soft armor model.
- Then compare the stated weight, thickness, care instructions and price, and try the plate in its carrier.
Conclusion and final thoughts
The material in a plate affects its weight, how it must be handled and stored, and what happens on impact. It does not, by itself, say what the plate stops: that is the model's test record.
On ArmorList, a product's record shows its NIJ CPL status with the date the list was read, and the standards it was tested to. In our view, material choice is a handling and wear decision as much as a ballistic one: weigh how a plate will be carried, dropped and stored, not only what it stops.
Sources
- CJTTEC, NIJ Standard 0101.07 Information (read 2026-09-29)
- CJTTEC, Body Armor FAQs (read 2026-10-01)
- NIJ, Compliant Products List: Ballistic Resistant Body Armor (read 2026-09-29)
- NIJ, Ballistic Resistance of Body Armor, NIJ Standard-0101.06 (PDF) (read 2026-09-29)
- NIJ, Ballistic Resistance of Body Armor, NIJ Standard 0101.07 (read 2026-09-29)
- NIST, Personal Armour Systems Symposium 2018 proceedings (read 2026-09-25)
- National Research Council, Opportunities in Protection Materials Science and Technology for Future Army Applications (2011) (read 2026-09-30)
- National Research Council (2011), Appendix E: Processing Techniques and Available Classes of Armor Ceramics (read 2026-09-30)
- CJTTEC, Body Armor Care and Replacement (read 2026-09-30)
- Egorov et al., Investigation of Anti-Ricochet Properties of Body Armor with Steel Armor Panels, Techniczne Wyroby Wlokiennicze (2009) (read 2026-09-30)
- Montgomery, Wells, Roopchand and Ogilvy, Low-Cost Titanium Armors for Combat Vehicles, JOM 49 (1997), U.S. Army Research Laboratory (read 2026-09-30)
- U.S. Army Research Laboratory, report on Ti-6Al-4V armor with RMI Titanium Company (DTIC ADA329568) (read 2026-09-30)
- Impact response and energy absorption mechanisms of UHMWPE fabric and composites in ballistic applications: a comprehensive review, Composites Part A (2024), doi:10.1016/j.compositesa.2024.108314 (read 2026-09-25)
- Tsinas et al. (NIST), Effects of Thermal Aging on Molar Mass of Ultra-High Molar Mass Polyethylene Fibers, Polymers (2022) (PMC) (read 2026-09-30)
- CJTTEC, New Ballistic-Resistant Body Armor Standard Published (read 2026-10-01)