Steel is everywhere, and most of the time we pay no attention to its presence. But sometimes, when we’re buying certain consumer products, we have to pay some attention on what steel was used to make that item. That’s because the steel used for the item will most likely be the prime factor in determining its quality. And this concern leads us to AR400.
If you’re doing some online research on the properties of AR400 steel, then your search for the pertinent information is over. This guide has it all. You’ll know the defining characteristics of AR400 steel, its pros and cons, its uses, and even its precise chemical composition. you’ll get the answers for questions you may have about AR400 steel, and you’ll even see how it compares to other similar steel alloys.
What is AR400 Steel?
The AR series of steels are named this way because they’re famous for their abrasion resistance. When you get it in steel plate form, it shows terrific resistance impact, fatigue, and wear. In fact, it’s nicely resistant to corrosion as well.
There are several steel alloy options in the AR series, and the AR400 is a popular option for certain situations. It contains a certain amount of carbon for hardness, but it’s a rather low amount. It’s mostly used for cases when the steel component has to deal with excessive wear, high impact, and potential abrasion, while the user also needs easy fabrication properties.
For consumers, the AR400 steel is a common option for steel targets when you’re practicing your shooting skills. It does the job without forcing you to pay too much for your targets.
Common Uses of AR400 Steel
- Steel targets for pistol and rifle shooting practice
- Lining for mining equipment
- Bucket liners
- Dump truck liners
- Material transfer chute liners
- Storage bin liners
AR400 Steel Chemical Composition
There’s really no single specific chemical composition for AR400 steel, as long as it meets the required hardness level. Sometimes the amounts for certain elements can change depending on the thickness of the AR400 steel plate.
Still, this is a typical chemical composition for AR400 steel:
- Carbon, 0.17% to 0.25%
- Manganese, 1.5%
- Phosphorus, 0.025%
- Sulfur, 0.005%
- Silicon, 0.50%
- Chromium, 0.20% to 0.60%
- Molybdenum, 0.05% to 0.60%
Carbon, 0.17% to 0.25%: The carbon determines the hardenability of the steel and its resulting hardness. As you can see, there’s really not much carbon here, which is why it isn’t used for knives. But it’s still harder and better at resisting abrasion and impact force that non-carbon steels.
Manganese, 1.5%: To compensate for the low carbon level, AR400 steel has a relatively large amount of manganese. Manganese ranks second in importance among allying elements, next to carbon. It boosts tensile strength and hardenability, and it also helps to take out unwanted oxygen and sulfur from the molten steel. with this much manganese, you get terrific surface quality (which is why it’s great for shooting target practice.
Phosphorus, 0.025%: You don’t really want a significant amount of phosphorus in any steel alloy, because it’s regarded as an impurity that can lower toughness and ductility. It makes the steel brittle.
But in tiny amounts, it can help with the machinability and the tensile strength of the steel.
Sulfur, 0.005%: This is another “impurity”, which is why it’s only present in such a miniscule amount. When you have high sulfur levels matching with low manganese levels, you get lower impact resistance and ductility. But when you really limit the sulfur content, it can help with the machinability of the steel.
Silicon, 0.50%: This is mainly a deoxidizer, meaning it takes out the unwanted oxygen bubbles in the molten steel. It also strengthens the steel when it dissolves in the iron.
Chromium, 0.20% to 0.60%: When you have at least 10% or 12% chromium, you have stainless steel. Obviously, you don’t have that much chromium here. This amount of chromium is mainly to boost the yield strength and hardenability of the steel, though it can still help with corrosion resistance.
Molybdenum, 0.05% to 0.60%: This helps with creep strength, strength in higher temperatures, and hardenability. It also helps with corrosion resistance.
AR400 Steel Hardness
On the Brinell scale a steel qualifies as AR400 if it exceeds 359. But as the name indicates, you often get a Brinell hardness rating of about 400.
While that suffices for steel targets when they’re made in sufficient thickness, that’s not really hard enough for use in knives. Converting that Brinell score of 362 to 427 in the Brinell scale gives you an HRC rating of 39 to 45 HRC. That’s just too low, considering that the HRC rating for knives average about 52 HRC, and plenty of good knives are a lot harder for better cutting performance and edge retention.
Still, given the right thickness it’s great for steel targets, along with certain other industrial applications.
Properties of AR400 Steel
The AR400 steel is notable for certain qualities that make them valuable for some types of applications:
The AR400 steel isn’t really all that expensive, which makes them suitable for high-volume use. What’s more, they offer terrific properties especially when compared to other steels in this price range.
Terrific Abrasion and Impact Resistance
This is one of the main reasons why the AR400 steel is useful for a wide variety of liners that tend to encounter a lot of impact forces (like for mining and material handling equipment). It’s also the main reason why it’s great for target shooting.
The surface quality is great, and it doesn’t deform easily when faced with abrasion and impacts. It’s also strong enough to withstand bullets even when the thickness is less than a quarter of an inch.
You need AR400 steel for various parts that will have to endure a lot of wear. That kind of heavy-duty wear can lead to failure very quickly. That can be risky, and it can lead to heavy damage to your expensive equipment. Also, without steel that can resist wear properly, then you’d spend more money replacing components too frequently.
Sure, there are other steels out there that may be even more resistant to wear than AR400 steel. But they’re almost always more expensive. With this price range, you’ll have a hard time finding a more wear-resistant steel than AR400 steel.
Excellent Corrosion Resistance
True, it’s not actually stainless steel. But stainless steel is a lot more expensive, and it may not contain the hardness you want.
With AR400, you get terrific corrosion resistance. That’s great for your steel targets, especially when you use them outdoors. These steel targets won’t easily rust, especially if you take good care of the targets. Just wipe them dry thoroughly when the targets get wet. In many cases, you won’t even have to do that—the sun will just dry the wet spots quickly enough.
Easy to Work With
The AR400 steel is considered fair when it comes to machinability. You can use carbide tools with conventional equipment to do stuff like general machining, milling, tapping, counterboring, countersinking, and drilling.
It’s also good in its formability, and in fact, the low levels of sulfur and carbon lead to better shape control. But it’s especially easy to weld.
AR400 Equivalent Steels or Alternative
You may find articles and comments, or even data, suggesting that AR400 steel is almost the same as T1 and ar450 steels. But there are rather notable differences.
AR400 steel vs T1
While the AR400 steel may seem similar to T1 steel, they’re actually quite different. It only seems that way because they’re both hard and strong.
The T1 steel is excellent when used as structural steel, and the AR400 steel is never used for that purpose. With the T1 steel, you get excellent strength even in below zero temperatures. It holds up well to fatigue.
On the other hand, you use the AR400 steel mainly for its resistance to impact abrasion and also to corrosion.
AR400 steel vs Hardox 450
These are also very similar. The Hardox 450 steel is also known for its abrasion resistance, with good weldability and bendability. But the extra hardness (with 450 in the Brinell scale) gives you greater wear life, abrasion resistance, and lower likelihood of denting. But you may have to pay extra for these benefits.
Pros & Cons of AR400 Steel
Best AR400 shooting targets
These are all made with AR400 steel, so it would be redundant to talk about the steel again and again. The following list contains great shooting targets (especially for the price range), but they offer somewhat different advantages.
#1: Birchwood Casey USA World of Targets .22 Rimfire 1/4″ AR400
- Dimensions: 24.3 L X 25.2 W X 37.9 H (Cm)
- Weight: 3.958 Kilograms
- Country Of Origin: United States
- Product Type: Suitcase
You can rely on the quality of the targets here, as the Birchwood Casey brand has been around since 1948. This their World of Targets Bushwhacker model, with the BC-47522 designation. It’s US-made, so the quality control is there.
It comes with a portable design that weighs less than 4 kilograms, and you don’t need a single tool to set it up. It measures 24.3cm long, 25.2cm wide, and 37.9cm high. That’s about 9.5 inches by 10 inches by 15 inches.
The setup does go better when you use maybe a couple of tent stakes to secure the target in its place. Without those stakes, the target can “walk” as you regularly hit it.
You get an alternating popup rimfire target, with rugged AR400 paddles. These paddles measure 4 inches across and are about ¼ of an inch thick. Resetting the targets is easy enough, as you don’t even have pulleys or strings to deal with. It’s a lot of fun as you don’t really need to reset the targets at all.
Use this with .22 rimfire or with .22 handguns. It’s not really meant for larger calibers.
#2: ShootingTargets7 Steel Silhouette Target 3/16″ AR400
- Finest 3/16″ thick genuine AR400 steel
- 12″ x 24″ torso is an IPSC torso minus the D zone (AC Zone)
- Excellent for simulating an attacker
- Large target rings loudly when hit and is a ton of fun to shoot
- Hang with 12″ or 18″ straps +hardware
- Weighs: 12 lbs
- Mounting Holes: 1/2
This is a brand started by a veteran who is also a firearms enthusiast, who got bored with paper targets. He made his own steel targets, and that’s how it all started.
This time you have a silhouette target, so you can practice on shooting human-shaped targets. That way, you know if you’ve merely “wounded” your target or if you’ve “killed” him with your shot.
The A-C torso uses certified AR400 steel so you know you’re getting the right hardness level with the 3/16-inch thickness of the steel plate. It’s been cut to IPSC (International Practical Shooting Confederation) standards, which makes these targets all nice and official. This has the requisite yellow zinc plating on the steel target, to help with corrosion resistance and bullet spall.
The target has been CNC laser-cut so you have the torso and the head shapes, with the hanging holes along the shoulder. The high-powered laser used for cutting the steel makes sure that you get a minimal heat-affected zone. The edges are tougher so they’re less likely to chip off.
The mounting holes measure half an inch, and they’ve been designed to keep from cracking due to the harmonic vibration. When you hang this, it will move and make a sound to tell you if you’ve hit it with your shot.
You can rimfire and 380 rounds with these targets, and pellets as well. It can handle a maximum bullet speed of 2850 fps and 300 ft-lbs. of bullet energy.
#3: ShootingTargets7 22lr & 9mm AR400 Steel Targets
- Finest 3/16″ thick genuine laser cut USA AR400 steel
- Thin targets sound off when hit with 22lr or even tiny pellets
- Suitable for use with up to 9mm pistol
- Outstanding value these thin targets perform big for little cost
- Weighs: 6.2 lbs
- Mounting Holes: 1/2″
- Actual size is 11.5″ wide 12″ tall
ShootingTargets7 also offer this type of round targets, with “ears” as the mounting holes. Again, you get guaranteed AR400 steel with the required hardness. It’s also been laser-cut for neater and stronger edges, and the steel itself has been bead-blasted front and back before it was cut.
The specs are the same here, and only the shape is different from the other ShootingTargets7 option. This is also good for 380 and rimfire (and also pellets, of course). It’s meant for maximum bullet speed of 2850 fps and 300 ft-lbs. of bullet energy.
We tried this with 22’s, and it didn’t leave a mark on the steel. We did have to paint the target every time we went with another round of shooting. When we hit it, the target doesn’t just move to indicate that it got hit. It also made a nice, loud sound, which was very satisfying.
#4: ShootingTargets7 AR400 Steel Bullseye Target 10″ X 3/16″
- 3/16 AR400 is excellent for 22lr but suitable for rounds up to 9mm.
- Finest 3/16″ thick genuine laser cut USA AR400 steel
- 10″ gong has 3″ hole with 4″ x 3/16″ AR400 gong mounted behind it
- Center hits sound different and are easy to notice
- Weighs: 5 lbs
- Mounting Holes: 1/2
Yes, it’s another ShootingTargets7 option. The brand simply offers effective steel targets at the right price. Again, you have a circular target with the ears for mounting holes.
You get all the usual properties: laser cutting, yellow zinc plating, and bead-blasting before cutting. Again, the AR400 is mainly meant for 380 and rimfire rounds.
What’s different here is that there’s a well-defined bull’s-eye section, in a different hue. The sound is very different when you hit the center target, so you get the instant feedback.
The target isn’t painted as well, and it’s not always easy to see where you hit the target from far away. But you can paint the center target yellow and the outer target red, so you know right away exactly where you hit it.
This isn’t meant for more powerful rounds, but it can handle .22s and .380 ACP rounds. We put in more than 2,00 rounds for the .22 and maybe 400 rounds of then .380, and the target remains fine.
It’s true that the AR400 steel has certain notable limitations. You won’t find it used for knives of any sort, as it won’t really cut effectively. And it’s not strong enough for structural uses.
But it’s great liners of various sort, when you’re expecting a lot of abrasion and wear in its use. The AR400 steel can deal with abrasion and wear very well, especially when compared to other steels in its moderate price range. Add in the good corrosion resistance, and you have a steel that’s quite versatile.
For consumers, they work nicely enough for low-caliber target shooting practice. They last a reasonably long time without costing you a lot of money. With AR400 steel for your targets, it’s money well-spent.
Frequently Asked Questions
Can you drill AR400 steel?
Yes, though you have to be mindful and you’ll need specialized equipment. You can’t just use a regular handyman’s drill on an AR400 steel, especially if it’s thick.
Forget about using Harbor Freight bits for AR400. You’ll need good-quality HSS bits, and cobalt is great but not absolutely necessary. Keep the bits sharp.
You have to go slow, and you’ll have to keep it from becoming too hot. Just keep it cool. Don’t linger in the hole you’re drilling. You’ll want to prevent the chips from turning blue, or else it can harden in a jiffy. It can then be hard enough that you’ll have to resort to carbide.
For drilling holes in AR400 steel plates that measure 2.5 inches thick, you can sue a Hertel HSS bit, even without the cobalt. Use a TiN-coated Hertel spiral point tap.
What is the difference between AR400 and AR500 steel?
They’re fairly similar, but the AR500 steel is harder than AR400 (as the designation indicates). The AR500 steel usually has a Brinell hardness rating between 460 and 550, and it averages at around 500. The AR400, on the other hand, only has a Brinell hardness rating of 360 to 440. You go with AR500 steel when you need the extra wear and abrasion resistance, but you’ll pay a higher price.
Can you weld AR400?
Sure, you can weld AR400 steel. You can use the same welding methods (and also the same filler materials) on AR400 that you also use when melding mild steel.
Is AR400 steel bulletproof?
Well, the AR400 can be used for steel targets. That means you don’t really expect the bullets to pass through the steel plate when it’s made with AR400 steel. You can even use an AR400 steel plate target for shooting with a 223 at a hundred yards.
Of course, you may want to make sure it’s thick enough. It ought to be at least 3/16 of an inch thick, or else it would be too flimsy.