With a hardness range between 477 – 550 BHN, AR500 is known for its toughness and excellent wear resistance, along with fatigue and corrosion resistance. To be fair, AR500 does sell exactly two plates which are NIJ certified- a polyethylene level 3 plate, and a level 4 ceramic. This difference is due to the different compositions of each alloy. AR500. AUSTENITIC-MANGANESE STEEL CASTINGS — SPECIFICATION ( Fifih Revision ) 1 SCOPE This standard covers the requirements for austenitic manganese steel casti rigs. Carbon Steel (1050-1090, 5150, 5160) Plain carbon steel is one of the most popular materials used in axe forging. Compounds. for polymer combined with UHMWPE. Well, on the Brinell scale – which measures the hardness of steel, with the higher the number meaning the harder it is – mild carbon (130-160BHN) and stainless steel (160-200BHN) are relatively similar. 62mm FMJ 150fr @ 2750+50 FPS) > (ESAPI. WELDING MANGANESE STEEL is not exotic or complex. 33% Carbon and 0. AR550 is most widely found in the commercial body armor market and they can defeat all of the rounds listed above, including the common. The AR steel grades include: AR200, AR235, AR Medium, AR400/400F, AR450/450F, AR500/500F, and AR600. 3. 060% to 1. The AUS Series (Japanese Stainless Steel): The biggest improvement of the AUS series over the 400 Series is the addition of vanadium which improves wear resistance and gives good toughness. This specialized plate is designed for severe impact and abrasion applications. Granted, I would tell someone buying steel to not do so without that build up coat. In fabrication and construction, the composition and grade of the steel plate materials used have a tremendous effect on the end product. Typical Analysis Carbon (C) Manganese (Mn)For example, the most dense metal is Osmium (Os), with a density of 22. AR500 steel plate is made of high-strength, low-alloy materials, including carbon, manganese, silicon, and small amounts of other elements. It won. As per the official info page from the manufacturer, Big Horn Armory: “ (T)he AR500 Pistol is a large frame AR chambered in 500 Auto Max. AR500 Steel vs Hardox 500. Dynamic Armor 46100® (Dynamic MIL-A-46100) is a high hardness ballistic steel plate product that is available in thicknesses from 3/16” through 2” (4. 29 Density 0. 20 0. Hardox ® 550 always performs at typically 550 HBW — no matter the type of wear. I have also found that the copper jacketed steel-core bullets (i. With steel, you get all these features and could pay roughly $75 to $125 less per plate than ceramic. AR450: 430-480 BHN Typically. Let’s start off with the pros of steel since it’ll be short. Mills use a hardness test – the Brinell Test – to determine the category. 0 g/cm3, aluminum is 2. ASTM A500 carbon steel tubing from Alro Steel is a standard specification for cold-formed welded and seamless carbon steel structural tubing in round, saquare, and rectangular shapes. Made with a custom steel alloy blend, this level 3 plus protection defeats all pistols. Renowned for its high impact strength and resistance to abrasion in its hardened state, the steel is often described as the ultimate work hardening steel. The hot rolled steel is drawn through a sequence of reducing dies or rollers that cold-work the steel into a strand hardened form, improving mechanical properties. [1] Mangalloy is a unique non-magnetic steel with extreme anti-wear properties. There isn't a lot of information other that it's hard and tough. 2 REFERENCES The Indian Standards listed in Annex A are necessary adjuncts to this standard. Swedish Steel Oxelösund AB (SSAB) produces a number of grades of steel, which have previously been assessed against AP ammunition. Manganese steel has no equal in it ability to work-harden. Plate thickness’ start at 3/16” and can go as thick as ten inches. ALLOY STEELS – Added alloying elements into the steel such as nickel. A514 >2. Think of dropping pick up sticks. MIL-A-12560 high strength armor plate is specified by the Material Technology Laboratory, Department of the Army, and is available to all departments and agencies of the Department of Defense (DOD). There are different types of steel, for example, AR400 OR AR500, that are produced to a specific hardness. Abrasion Resistant steel is one of our most popular products at Clifton Steel. Both Er70S-6 and ER70S-3 are solid wires used for TIG and MIG-MAG Welding of Carbon steel/ mild steel material. 6%). There isn't a lot of information other that it's hard and tough. I donated a 15" dia, 3/4" thick, swinging gong to my 50BMG rifle club. Steel with particular properties and traits is created by adjusting the overall chemical composition or by altering the varied production processes such as rolling, ending, and. Manganese steel is known for its high impact strength and resistance to abrasion. Use bullet speed AT TARGET or muzzle velocity for worst-case scenario. AR200 steel is an abrasion resistant medium steel plate. Hardox 450 vs ar500, Q345B low alloy steel plate composition: 1) Low carbon: Due to the high requirements for toughness, weldability and cold forming properties, its carbon content does not exceed 0. If your activities call for high wear resistance levels, you should choose AR400 steel. Once a piece of steel is pulled past its tensile stress point, it will split apart. We provide the Industry's Best Abrasion & Impact Resistant Steel. The quenching and tempering combined with the addition of carbon and manganese increase the hardness of it and by creating an impact-resistant surface it is well suited in handling abrasive materials. Regardless, it wasn't designed to be used for body armor or personal wear. . Specifications AR400 / 400F AR450 / 450F AR450 / 500F; Hardness (BHN) 400 (360 min. None of this is to say that steel armor. 2″ -> 1. NM500 VS AR500. Basic melting practices are required because of the severe attack on acid refractories. The weight of steel armor varies depending on the thickness and size of the plate. 11-14% Hadfield Manganese Steel is a nonmagnetic, impact resistant steel that is generally used for applications that are subjected to high levels of impact and hammering. Hardox ® 550 is a genuine alternative to wear parts made of manganese steel. 70 carbon manganese silicon steel plates steel price, please do not hesitate to contact us. 04 max:8 = Nickel – Chromium – Molybdenum Steel. (T)he AR500 Pistol. What is ar500 steel? AR500 steel plate is chemically similar to AR400 steel plate, except the hardness range is higher and it has more carbon and manganese. 56 threats, though M993 might penetrate. 20. AR500 will take hits at close range from . But too much will significantly reduce the ductility. In this article, the production of abrasion-resistant steel plate is described and the differences between hardness levels are studied. It’s often referred to as Hadfield steel, or Hadfield grade, as Sir Robert Hadfield discovered it in 1882. Aluminium 6082 is stronger than 7075 in tension, while 7075 is stronger in compression. This article aims to explore the similarities and differences between AR400 vs AR500 steels, providing a comprehensive. Manganese steel also contains. Manganese steel rarely reaches 550 HBW. The much heavier versions, especially centered caliber model guns would require something stronger. Medium carbon steel – Medium carbon steel has a carbon range of 0. 2. Therefore, AR400 will have a lower. 223 at 100 yards. Manganese steel is. Mangalloy is made by alloying steel, containing 0. ) 450 (429 min) 500 (450 min. except the hardness range is higher and it has more carbon and manganese than AR400. 315” thickness offered in 48”- 65” wide, cut to your requested length. This type of steel provides excellent strength and durability while also being cost-effective. 2100-4000ft-lbs = ½” AR500. A514 steel plate is a high strength, machinable, and weldable steel that Kloeckner Metals stocks across its nationwide 40+ branches. 11-14% (Hadfield) Manganese Impact Steel. 33 and varies based on the dimensions or any customizations of the grade. 21 – 0. AR250 steel plates are made for improved formability with low levels of carbon and sulphur for inclusion shape control. We have warehouses in IL/CA/IN/OK/OH with large on-hand inventory. MIL-DTL-12560 Rev K. 4140 is a great basic chemistry that is easily modified at the steel mill by use of additional elements to achieve additional, and/or, specific properties for specific industries or jobs. Adding up to 0. D. AR400 vs AR500 steel plates are two of the most popular abrasion resistant steel plates in the world. 38-0. The last two digits are how much carbon is in the steel. Hankev is an industry leader in depth, breadth, and availability, serving over 1000 customers worldwide. While AR450 steel is similar to AR400 and AR500, there are some variances that make each unique. AR400 vs AR500 steel plates are two of the most popular abrasion resistant steel plates in the world. As in the case of titanium, vanadium, and chromium, the. Among the most notable things about the AUS10A steel is its hardness. 31% to 0. 2 for steel, 8 lbs. 1-800-745-3962 [email protected] Shipping; Home; About. AR600: 570-625 BHN Typically (less common, but available)S7 tool steel is generally more expensive than AR500 due to its high-alloy composition and specialized manufacturing processes. The answer is GB standard Nm500 Nm450 Nm400 steel plates. Gun nuts (like me) loved the dinosaur, buffalo and other "dangerous game" critters I would cut out. These plates are curved and have dimensions of 10″x12″. AR500 steel is an alloy made primarily of iron, with small amounts of carbon and other elements. 95% to 1%. C. For instance, if you need high hardness that is deeper and more uniform, you could add Nickel to the 4140. Innovative solutions. P) Machining Guidelines. . 6% carbon), and High carbon steel (more than 0. The number of electrons in each of Manganese's shells is [2, 8, 13, 2] and its electron configuration is [Ar] 3d 5 4s 2. Manganese steel is an alloy composed mainly of iron (Fe) and manganese (Mn). That extra 1/8” from 3/8->1/2 makes a huge difference in rifle durability. As noted above, all you should have on AR500 plate is a very small divot about the since of the head of metal stick pin with . . P. AR500 and AR550 are both designed to withstand many rounds of shooting. Manganese (atomic symbol: Mn, atomic number: 25) is a Block D, Group 7, Period 4 element with an atomic weight of 54. NM500 Chemical Composition. On the other hand, AR500 is ideal due to its high levels of resistance and. 1% to 1. 024” thick or 24 gauge piece of 304 stainless. In summary, both S7 tool steel and AR500 are high-quality steels with exceptional strength. Mangabraze. The cushioning quality of this base metal allows it to absorb impact. AR500 steel is an incredibly durable material used in snowplows, tanks and rock crushing machines. With a tensile strength of 247 ksi and a minimum yield of 187 ksi, it provides extraordinary Oct 7, 2021 | Steel Products Manganese steel is a steel alloy containing 11-14% manganese. The caution here is that you must comply with the recommended thicknesses vs. 3 lbs. Strength. Birchwood Casey World Of Targets Qualifier Spinner Rimfire Target. Big Horn Armory has introduced the AR500 in a new cartridge, the . Plus, we’ve included a separate table on the shear strength of steel when heated, so you can make informed decisions about material selection and processing. Peen the welds while hot. Best Wear Resistance of any abrasion resistant plate. 1/2 inch nm500 vs ar500 . Manganese Steel vs. 04%; Sulphur, 0. As a. Tacticon Armament’s AR600 10×12 can weigh as little as 6. Standard plate sizes that are 48" x 96" and 60" x 120". It is necessary to ensure excellent metallurgical quality, not only to ensure accurate chemical composition, but also to have high purity. 338 LM has massive amounts of energy. Ultima™ 501 (AR500) Wear Plate; Ultima™ 601 (600 BHN I. As a high strength Carbon Manganese steel, ASTM A529-50 can be easily welded, and its ductility and durability make it a common option for bending and stamping projects as well as heavy duty applications. TITUS AR 500 Steel Plates are heat treated and intended for severe wear applications requiring a high degree of abrasion resistance. 2-4 times greater life than conventional 500 BHN steels. . What is AR500 Steel? AR500 steel is an alloy that contains added alloys such as carbon and manganese. Amuda, in Reference Module in Materials Science and Materials Engineering, 2017 6 Work Hardening. AR500 vs AR550 vs AR600 Body Armor. Damage on the stand and upright is consistent with that of the steel. AR steels are a great choice to build a gate, valve or diverter if you deal with high. However, SSAB has two UHH armor steels designated ARMOX 600T and ARMOX ADVANCE that meet this hardness criteria. These forms (called compounds) are. This alloy has high strength and excellent corrosion. This specialty plate product is specifically designed for lightweight armor applications that require maximum resistance to ballistic threats. 45 7N6, steel jacketed ("bimetal") Tula 223, and plenty of other ammo at a new piece of AR500: use known AR500, use 1/2" thick or better, put it on a slant if able. AR500 steel can withstand the abrasion that the rocks cause by sliding better than the AR400 steel, meaning it would last longer. Steel armor gives you a high ballistic rating, multi-hit capability, edge-to-edge protection, extreme durability, and long shelf-life. Hadfield Manganese steel typically has a direct 10 to 1 ratio of Manganese to Carbon. Industries like aggregates, mining, shredding, railroad, steel mills, foundry, and others trust our steel wear plate products for their most. Introduction. No matter what the steel plate thickness or the grade, we’ll have whatManganese Steel castings can be made by any of the conventional steel-making methods, however the Electric Arc Melting Furnace process is the most common. Level IV steps it up and stops almost all rifle rounds including purpose built AP designs. Hardox ® 550 always performs at typically 550 HBW — no matter the type of wear. There are a lot of misconceptions about shooting steel. The basic components of pearlitic pipeline steel are carbon and manganese, generally speaking, the content is 0. But the second ricocheted off to the side. The best steel targets for 9mm are made of 3/8″ thick AR500 steel. Dec 14, 2022. Enhances machinability by integrating with sulfur to form a soft inclusion in the steel, enabling a consistent built up edge along with a place for the chip to break. It’s not really used for knives, either. . 16:14. MegademiC. And if it does, it happens only when exposed to extreme impact wear. It's primary application is for high abrasion environments (AR means abrasion resistant), but it is also a great steel for targets. At Clifton, for steel to be considered AR400, the plate must measure between 360 and 440 BHN. Specifications. H. Steel Warehouse can supply the following sizes of AR500 Steel: . SR500 is a new type of ballistic protection steel specifically designed for use in targets, ranges and other armor applications. 11-14% Hadfield Manganese Steel is a nonmagnetic, impact resistant steel that is generally used for applications that are subjected to high levels of impact and hammering. Clifton Steel is a leader in custom metal and steel fabricating services complete with machining, cutting, and forming capabilities. Level III plates built from UHMWP/Dyneema are vulnerable to steel penetrators like M855 and M855A1. Even thick plates quickly get holes and craters if they are made of. 55% (Max) Nickel: 1. 62x54R Military Surplus 147 grain steel core rounds on our off the shelf Level III 10" x 12" Plate at just 30 rounds! All 5 rounds of 7. The ABREX Series features 3 standard options of abrasion resistant steel plate in addition to 2 extra tough options – a product range capable of meeting a variety of needs. Meanwhile AR500 / AR500F. At 300, you might want to go to the 1/2". Stainless steel is known for its corrosion resistance. As supplied, most manganese is furnished at a hardness of 225 to 250bhn. Less likely to separate than other alloying elements. 500 also has a higher hardness. 50W steel is a low alloy, high-strength steel that is predominantly made up of carbon, manganese, silicon, and a few other elements. Ultra Hi Strength Alloy Wear Plate. The AR-500 is indeed a . 5″) Ability to “Work Harden” from 470 BHN to 560 BHN. It will stop m855 green tip, etc. We are a Cleveland, OH based steel supplier with specialties in AR400, AR500, A514, Manganese Steel, Armor Plate, and other specialty steels. 1-800-745-3962 [email protected]Q&T Plate Grade. NM500 VS AR500, Structural steel is a kind of steel which meets the strength of specific specifications. Mirro-Krome 60® (I. 내마모강 (AR400,AR500) 2018. Type Carbon Steel Modulus of Elasticity 30,000 ksi Poisson's Ratio 0. AR 500 is similar to AR 400, but 25% harder because it contains more carbon. . Clifton Steel provides prompt delivery of railroad wear liners, coupler wear plates, shims, and other railroad wear parts. A quick Google also pops up a brand of body armor plates called AR500. It handles wear 8 times greater than mild steel. Hardox 550 comes in thicknesses of 10–50 mm (3/8–2") and widths up to 2800 mm (110"). AR500 is slightly stronger (in terms of tensile strength) than 400, by about 20-25%. Aside from the typical metals used to form steel, manganese is added to the mix to create this type steel plate. This is what Clifton Steel is known for and what makes us a leader in the abrasion resistant, impact resistant, and wear resistant steel markets. ASTM A516-70 Carbon-manganese-silicon steel plate for moderate and 156 lower temperature service in PV. Drinks cans are made of an alloy of aluminium with 1. AUS10A Steel Hardness. Copper Jacketed Lead bullets are. On the Brinell Hardness Scale, the product. Manganese steel is an alloy that contains between 10% and 14% manganese. With that said: 1) 3/8" AR500 plate won't hold up as well as 1/2" AR500 plate, not due to surface hardness but just general toughness. If the steel was fixed or hanging I'm willing to bet it would have nearly penetrated. Delivering a hardness of 550 Brinell, it offers a unique combination of excellent wear resistance, crack tolerance and workshop performance. 85 g/cm3, 304 stainless steel is 8. AR400 Steel, AR500 Steel, A514, Manganese Steel, Armor Plate + More. manganese, and so forth. For example,. 70 carbon manganese silicon steel plates steel in stock every month. They can differ in thickness depending upon thAt 200 yards nothing but some magnum varmint rounds should be able to pit ar500, unless you're running a lot of steel core. The main advantage of AR400 steel is its superior durability—it can withstand much more wear than ordinary mild steel and is more resistant to corrosion. C. 56x45mm NATO with M193 and M855 bullets as well as 7. Primarily used in military applications, but also in areas where high strength is required as both grades have elevated yield strengths (HY 80 – 80ksi, HY 100 – 100ksi). A common trademark in the United States for hardened steel is AR500. Rather, it occurs combined with other substances such as oxygen, sulfur, and chlorine. The hardness range of AR 500 is between 470 BHN and 530 BHN, making it more brittle than AR 400. 1 CTS Targets 3/8in Steel IPSC Silhouette Rifle Target – Best Affordable AR500 Steel Shooting Target. 534g/cm3). AR500 VS. The AR400, on the other hand, only has a Brinell hardness rating of 360 to 440. How thick the target is; In general, a thinner target will produce the loudest result. All of our steel body armor and ceramic body armor selections are made for optimal protection, premium comfort and exceptional value. This contributes to AR 500 steel plates being used in shoots and conveyors, where there is more sliding abrasion. MIL-A-46100. 60%, and a manganese content ranging from . AR500; Manganese Steel; AR250; A514; Chocky Bars; 4150 Steel Bar; Scrap & Recycling. 01%. Details. And if it does, it happens only when exposed to extreme impact wear. C1020/1020 Steel Plate. Origin: NM500 is a Chinese standard (GB/T 24186) for wear-resistant steel, while AR500 is an American standard (ASTM A36/A36M-08) for abrasion-resistant steel. If you have been looking for the best option for a bulletproof vest, you probably have come across the affordable option of AR500 or AR550 Steel Core Armor plates. Not a single model. It also reportedly makes the steel easier to sharpen. The 10xx steel series is notable for its significant carbon content. Hardox has high. AR500 steel has a hardness rating of around 500 HBW, making it highly resistant to surface abrasion and penetration. This test is inherently not scientific in nature. How many types of Hardox 450 vs ar500, pipeline steel are there? At present, pipeline steel can be divided into the following four categories according to microstructure. AR235 is a high carbon and manganese, abrasion-resistant steel. Chapel is one of the vendors that makes this stuff. ) Shaft;. An extra 50 Brinell goes a long way with. If the Manganese has work-hardened in service (such as may likely be encountered in repair jobs), cut away the hardened surface. What is manganese steel? Manganese steel, also called Hadfield steel or mangalloy, is a steel alloy containing 12-14% manganese. Manganese steel also resists heat, and maintains its elasticity in temperatures up to 1130°C, making them perfect for. Request a Quote for A514 Steel Plate. This means that AR is harder due to the addition of carbon, and formable and weather resistant due to added alloys. Unlike common abrasion-resistant plate, which focuses on hardness alone, the unique, rich chemistry of Mangabraze develops work-hardening toughness as well, to resist. One of the most significant differences is their hardness level. Chocky bars are steel wear blocks that are easy to fit and easy to install for maximum wear resistance. The common delivery status of Hardox 450 vs ar500, SA516 Gr 70 plate is as follows: 1) SA516 Gr 70 plate quenching: the process of rapid cooling after heating to the temperature above the phase transformation point. With a Millermatic 180, you could do 3/16" (. Subreddit for both professional and civilian tactical gear. It exhibits excellent work hardening characteristics in service applications where impact and abrasion are prevalent. As a general rule, AR450 and AR400 are the “sweet spots” in terms of good formability combined with good hardness. 30-06 round going through an AR500 level 3, but not through a level 3+: The jump up to level 4 body armor is a matter of personal choice. SAE steel grades. . e. Valast® 450 :125” - . Creusabro® M is the genuine fine-grained 12-14%Mn austenitic manganese steel (Hadfield steel) hot-rolled plate. Most people aren’t really all that familiar with AR500 steel, even though it’s widely used in many industries. These are exemplified, respectively, by the manganous salts (with manganese as the Mn 2+ ion), the manganates (MnO 4 2−), and the permanganates (MnO 4 −). It couldn't hurt except for the cost. Hesco L210 vs AR500 level 3+ LW Both are the same price and weight. 5. >Normally will be of a lighter weight than rifle threat steel armor. It reminded us, that others likely have the same question or experience. With 4-5 different options, how do you know which option is best suited for your. . Best Ceramic Level IV Body Armor. AR500 Steel works for both handguns and rifles; Lower grades of steel can be dangerous and do not last as long; AR500 Steel is Heat Treated to a higher hardness of about 500 BHN; Other mild steel is not heat treated;Apr 19, 2009. Clad wear-resistant steel vs AR500 wear-resistant steel. 02-27-20, 15:17 #7. A514 >3/4” to 2. Thanks in advance. Multicurve AR500 levIII+ plates with extra coating end up being $177 a piece without shipping. Material Machinability Chart - Machinability of Metals The metal with a machinability rating smaller than 100% means it is more difficult to machine than B-1112 (carbon steel 1212) and materials with a rating. 05. 250) with beveling. AR500 Armor, Level IV Ceramic. 1095 steel, when used in knives, holds a great edge and is very easy to sharpen. All in all, unless you're trying to cut into opponents you want durability more than you want hardness, so AR500 is the better material. Titus Manganese will work harden from 280 BHN to 550 BHN—which is an increase in hardness of over 200%. AR500 Armor. These elemental differences help the steel achieve a higher surface hardness. MIL-DTL-46100 REV E. $430 to make steel useable, but even heavier, or $540 or so for hesco L210's, or TSG LevIII+ lightweight polyethelyne, or levIv RMA's. Ductile failure – think of this as the preliminary stage of failure, where it is pushed beyond the yield. And Mn16 belongs to high manganese steel, is a widely used wear-resistant steel, wear-resistant and impact resistant. 1. 1. If you want to get the ASTM A573 Grade 70/A573 Gr. AR400 steel falls between 360 BHN and 440 BHN, whereas AR500 steel falls between 477 BHN and 550 BHN on the Brinell Scale. 1-888-564-7904 . Titus Manganese Steel work hardens to 550 Brinell & is non-magnetic. With M33 you should be ok at extended ranges. 98 per kg, while the same plate starts at $3. The grain size is also enhanced and uniformed in this process. 938045. What is the difference between AR400 and AR500 steel? The Brinell Hardness number differentiates the abrasion resistant steel grades. However, steel plate can be purchased in sizes as large as 120" x 480". Aluminum manganese alloys: 3A21: Annealed: 70～100: 110～145: 19: 50: 71000: Semi-cold hardened: 100～140: 155～200: 13: 130: Aluminum-magnesium alloy Aluminum. It’s often referred to as Hadfield steel, or Hadfield grade, as Sir Robert. ATS 55 Steel - This steel does not have the vanadium that is present in both ATS-34 and 154-CM. Due to its high strength and wear-resistance abilities, A514 is typically used in applications such as construction equipment – like cranes – and large, heavy-load machines. $30. Brinell Hardness Number (BHN) : AR200/AR235/AR Medium: 180-250 BHN. Cladding wear plates are more wear resistant because the cladding plate is made of an alloy to improve wear resistance. When something other than a non-magnum pistol caliber is used on the range, he's careful to make sure it only goes at the AR500 target. But for lower grade or even thinner metals, the smaller higher velocity projectiles, would disrupt the base metal at a metallurgical level worse than the bigger lower velocity projos. The CTS Targets 3/8” Steel IPSC Silhouette Rifle Target is the classic steel silhouette target. . The AR500 is even more formidable than the AR400 when it comes to abrasion resistance. It is designed for high wear applications and is often used in the mining or material handling industries. high manganese steel electrodes and fluxes for submerged arc welding. 6 pounds. Eventually, the customers and their team will be the best judge of which material is required for their project. Steel’s affordability has made it an increasingly popular material for body armor. I've see that caliber knock around 18" circular plates of AR500 (3/8" thick) at 300yrds like they weighed nothing. 10% - 0. It means that ar500 isn't actually a steel alloy, but just a market-friendly way of describing a certain type of steel that has been exposed to certain heat treatments.