How to Make Ballistic Plates for Body Armor

How to Make Ballistic Plates for Body Armor

Body Armor and Ballistic Plates should be standard PPE (In accordance to MOPP Standards) for your team. The presence of hostile elements in all disasters (man-made or natural) is an eternal truth. Having access to these plates will make the difference between life and death. Ideally, you want standalone ballistic plates that can be used in conjunction with a plate carrier instead of a bulletproof vest. The most basic and user-friendly way to achieve this is with heavy steel plates that have been improved.

Typically, people tend to ‘make’ stand-alone steel ballistic plates that are nothing more than a 10″ x 12″ x .25″ piece of steel. While these steel plates are capable of stopping .223/5.56 ammunition, they are very heavy. A .25″ steel ballistic plate’s average weight is 8 lbs.

Ballistic plates can vary from what size round you intend it to withstand and how much weight you can carry. Most ballistic plate carriers hold four plates; front plate that protects vital organs, rear plate that protects your spine and vital organs, and two side plates. There are several different options in ballistic plate ranging from polyethylene, ceramic and steel which I will be covering in future articles.

How to make Level III Ballistic Plates

A Level III Plate refers to rifle protection. For a ballistic plate to be considered Level III it must be properly tested. Test your plates in the field by firing 6+ rounds of 306 FMJ and NATO 7.62 x 51 mm. If there is no penetration by these rounds you have a standard Level III Plate. Testing is vital, zero penetration is the goal.

First of all you will need a ballistic plate carrier and the measurements on the pouch that holds your plates. You can usually find good deals on Amazon for Ballistic Plate Carriers. A common size for a standard plate carrier is between a 10″ and 12″ plate. If you choose to take an alternate route and use a modified tactical plate carrier with your own custom sized pouches then make sure to take measurements of the size plate you will need.

To effectively make an efficient plate you will need some source of heat to bend and temper your plate i.e. torch. Also I prefer a wet saw for cutting your plate to size, and you will need welding gloves or clamps to hold your material i.e. used motor oil.

Before I begin the process of making your ballistic plates I would recommend using at least a 3/8″ plate which can withstand most 7.62 rounds.

After you have the correct size of your plate and cut your material to size you will need to heat your plate. Using a torch you want heat your material evenly till you see your plate glowing red-hot. Do Not hold your torch in one place too long or you will burn a hole through the plate. Once you have your plate heated I suggest clamping it to a work bench to add a slight curve to the plate. If done correctly your plate should sit level on a table and your highest point in the center should only be about 3/16″ high.

Now Its time to temper your plate which is also referred to as hardening steel and this is where the used motor oil comes in to play. Take your used motor oil and pour it into a bucket preferably metal so you don’t burn holes through a plastic one unless you have steady hands.  You will need enough oil to completely submerge your plate. Once again you will need that heating source. Heat your plate evenly till it glows, then submerge your hot plate into the motor oil. The reason behind using used motor oil is the carbon deposits in used motor oil. As most know, metal expands under heat due to the molecules separating when submerged into motor oil. The carbon deposits fill in the spaces that the heat caused, making hardened steel.

Now you can clean off your plates and place them in the pouch of your vest, but as I said earlier this will stop small arm and most 7.62 rounds. However, there are a couple drawbacks to using this method. Fragmentation is one possible draw back. When the round strikes a steel plate carrier it can fragment and send the debris into soft-tissue. Also if a polymer tipped round strikes it will not fragment but will send the kinetic energy to the place it strikes. So my suggestion is to have an additional layer of protection between the plate and your body. One option is a layer of Kevlar or polyethylene both in front of your plate and behind this will absorb any kinetic energy or fragments that the round causes.

Physical Considerations for Body Armor

Due to the weight of ballistic plates your joints and ligaments will take a beating, especially if you’re not physically trained. This added weight forces your muscles to work harder.In addition, back injury is likely if your body is not properly trained to carry the additional weight in the correct manner. To correct this include the use of ballistic plates in your combat and survival training.

Addition From User Comment on Kevlar Plates

To me, it makes more sense to use several thinner layers of steel and UHMW polyethylene and a kevlar wrap. Hardening and tempering 2 layers of 1/8in cold roll steel sandwiched like this:

6 layers Kevlar
1/4in UHMW
1/8in steel
1/8in UHMW
1/8in steel
1/4in UHMW
6 layers Kevlar;

should provide a high level of penetration resistance, energy absorption and spalling protection.

The used motor oil provides 2 important parts to the hardening/tempering process. One, it provides additional carbon to the surface of the steel. Two, it slows the cooling process allowing more time for carbon penetration. Yes, this is similar to case hardening but, due to the slower cooling, the carbon goes deeper than case hardening compound. The red-hot quench JDawg speaks of in “forging” is an initial hardening process that aligns the molecules and creates tighter bonds within the metal’s grain. The red-hot quench also equalizes stresses within the metal. The blue heat-quench JDawg speaks of is a stress relieving step, better known as tempering, which adds flexibility to the metal by relieving the surface tension of the work piece.
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About CMF Contributor Barnes

Arc and plasma cutting and spot welding perfectionist with a Mechanical Engineering Degree. AWS Welding Certification with two decades under my belt. Creative survivalist and defense minded person at heart.

20 suggestions on “How to Make Ballistic Plates for Body Armor

  1. I would like to make a correction although the 3/8 plate will stop small arm rounds. It will take 3/4″ Of steel plate (only plate) to stop a NATO round. That is why I suggest to use it in conjunction with kevlar or polyethylene to slow the travel of the round.

  2. We’ll be posting videos on our Facebook showing the results of this method in the beginning of June. Thus providing a better understanding for readers. Thanks for the clarification.

  3. Cool! Funny that you guys posted this. I just finished my plates last week, and hope to test them over the holiday. In addition to hardening the plates, I also tempered them in our oven at work. Hopefully this will stop any fragmentation. You can do the same thing with a torch by heating a plate that is polished with a wire wheel (easier to see color change) and watching for it to turn a nice cornflower blue, work the torch over the piece till you get a nice even blue. Then set the plate aside and allow it too cool. Look forward to your video!

  4. Having thought about this, and a friend recommended ebay as a source. For 2 plates, certified nij III rounded for about $125 and about $160 including side panels.

    Would you recommend side panels or just the main panels?

  5. Pingback: How to Make Ballistic Plates for Body Armor |

  6. To help control spalling/fragmentation, try coating the finished plate with RhinoLiner — the same stuff you spray into a truck bed…..

  7. So with a bit of looking, to fit the criteria you laid out I’m looking at about $25 a plate in materials as long as I’m willing to make a few plates at a time. So going off Robert’s numbers that’s roughly a 60% savings vs buying certified plates.

  8. Do you have any idea how heavy a 3/4 in plate is going to weigh and slow you down? Thats all good and fun to try to make your own gear but dont put your life in danger and spend the $200 and get a set of real plates that ahve a NIJ rating. Steel plates to begin with are junk because they spall when they get hit. You need a few layers of kevlar in front of them to mitigate that risk. 3/4 in steel plates, really? Factory ballistic level 3 plates i have are less than 1/4 in and weight over 10 lbs easily. I cant imagine what the 3/4 in plates weight and how theyd hinder mobility.

  9. Dwayne

    Thickness of plate in inches x .2836 x 144 = weight per square foot.

    That is the formula to figure out the average weight of steel plate. Most plate carriers hold a plate roughly 10″x12″ so figure a square foot per plate, that’s roughly 10 pounds for 1/4″ plate (of which there are several companies that sell NIJ III rated plate of this thickness). For 3/4″ that’s almost 30 pounds. spalling can be mitigated by something other than Kevlar. The various forms of durable spray on liners are effective in that though they will begin to deteriorate, so long as the interior plate is unharmed they can be reapplied. The carrier itself does some of this as well, since most of the force of the bullet is lost once hitting the plate.

    Of course, anyone that would make either plate and not test it for themselves is asking for trouble, but its still a calculated and reasonable risk because steel plate has advantages that factory inserts do not.

    Long term storage. Kept in a environment similar to guns, say a safe, it does not deteriorate in protective qualities. Factory vests have to be inspected yearly for the formation of cracks or overall brittleness that will lessen their usefulness.

    Ease of maintenance. Because there is none other than a visual inspection to see the physical integrity of the plate. And faults are evident to the naked eye so do not require xrays as ceramic and other plates do.

    Availability. No one is going to bat an eye if you order and have metal plate delivered to your home. Given the state of things currently, if you are not associated with law enforcement or military how likely is it that some system somewhere has tracked the fact that you have ordered ballistic plate?

    Secondary Use. Should the plate begin to fail, the metal itself is still of value and can be re-purposed to make any number of things. Factory plates, once failure is detected have no realistic secondary purpose.

  10. I’m not entirely sure about your tempering science… I always learned that carbonization is done in the smelting proccess, something about using airflow to have the oxygen oxidize with impurities and then carry them away in the smoke…

    also i know from medieval steel you want to blue and quench the steel after your initial red-hot quench

    but i came here because i dont know about ballistics, however my instinct goes against what you’ve written, however i feel like you may be right, and i’d just like you to further explain your carbonization process

    (it also seems like the oil’s carbons would only penetrate the surface of the steel, so it it kind of like a hard outer layer that sleeves the softer core? like a samurai sword)

  11. you also mentioned using kevlar or polyethylene to help slow the round? do you mean to put that on the outside of the plate, or on the inside of the plate, or some division of both?

  12. JDawg, I think the reason for the oil is different from what USCrow gave but it’s still true. In quenching in oil the heat is pulled out of the steel slower. This allows it to harden without becoming brittle and is a step in case hardening (like you’re beginning to describe with medieval steel). After this slow quench you would heat the metal again and quench it in fresh water. This gives you a harder exterior without making the entire piece brittle.

    As for kevlar, what you’re looking for are ‘soft armor backers’ and what they are is thinner layers of kevlar that don’t offer much ballistic protection on their own but when paired with a stand alone plate they increase it’s protection so a lighter armor can offer proper protection when weight is an issue. They’re typically worn in the carrier between the stand alone plate and the body. This way they offer protection from fragmented bullets and extra padding from the impact of the shot. They’re usually about 6mm/.25″ thick and add about a pound and are sold in pairs (front and back) for around $300. They are a sound investment for long term storage vs ceramic plate or similar that needs bi-yearly x-ray inspection.

  13. I’m not a huge fan of the idea of case hardening ballistic plates, “softer core” sound horribly bad when you compare it to the speeds of some of the rifle rounds out there. I would put alot more trust in the whole piece being as hard as it can while still being flexible enough to not shatter. I’m going to put more trust in steel that’s been tempered as hard and brittle as it can be and then tempered to spring hardness, it’ll bend just a little before it ruptures through instead of shattering, so when the bullets hit, if they’re defeated they’ll just dent the back, and there’s no chance of a hardened case ripping open to expose a core so soft that it cant flatten the round.

  14. From what I understand about CMF contrib’s process, it seems he’s maximizing the temper of the steel in order to get the most hardness possible out of it, possibly at the cost of leaving it brittle?… I’m not sure what the oil is for… And I’m curious if the piece is so hard it will just shatter, and if that’s what you want? (shattering reduces impact to the wearer) Or if the plate is going to deform instead of shatteing.

    That’s pretty much what I wanted to know, I wanted to hone back on that since I’ve started to drift.

  15. To me, it makes more sense to use several thinner layers of steel and UHMW polyethylene and a kevlar wrap. Hardening and tempering 2 layers of 1/8in cold roll steel sandwiched like this:

    6 layers Kevlar
    1/4in UHMW
    1/8in steel
    1/8in UHMW
    1/8in steel
    1/4in UHMW
    6 layers Kevlar;

    should provide a high level of penetration resistance, energy absorption and spalling protection.

    The used motor oil provides 2 important parts to the hardening/tempering process. One, it provides additional carbon to the surface of the steel. Two, it slows the cooling process allowing more time for carbon penetration. Yes, this is similar to case hardening but, due to the slower cooling, the carbon goes deeper than case hardening compound. The red-hot quench JDawg speaks of in “forging” is an initial hardening process that aligns the molecules and creates tighter bonds within the metal’s grain. The red-hot quench also equalizes stresses within the metal. The blue heat-quench JDawg speaks of is a stress relieving step, better known as tempering, which adds flexibility to the metal by relieving the surface tension of the work piece.

  16. You forget about the whole idea of SPAWLING when using solid steel. Where the energy is transfered through the metal place and fragments fly off the inner side…the side closest to you, against your skin. The same idea between knitetic anti armor rounds….its some pretty wicked stuff.

  17. Ar 500 plate at 1/4″ will stop 7.62×51 rounds, i have built plates and tested.
    the trick is you have to have a large press brake to curve them, I can sell a matched pair front and rear for $105, there is a company named Rhino armor that sells 12 layer kevlar pads for $55 per set that eliminates all spall.

  18. Casey, 1/4″ AR500 is good, solid stuff. Take that same, formed plate, sandwich it between 2 sheets of UHMW plastic of the same thickness and then back it up with kevlar pads and I think you’ve got one helluva piece of armor. What say you?

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