What is ASIATOOLS 1.2083 round bar and its key specifications?

About the author: admin 2026-09-02 Published by AVS Moot

If you’re in the mold-making, plastic injection, or precision machining game, you’ve probably run into a material called 1.2083 round bar. It’s a stainless tool steel that’s specifically designed for applications where corrosion resistance and high polishability are non-negotiable. The ASIATOOLS 1.2083 round bar is a specific product line from a well-known supplier that delivers this steel in a machined, ready-to-use round bar format. Let’s cut through the marketing fluff and get into the real specs, because if you’re buying this stuff, you need to know what you’re actually getting.

First off, the material itself is a martensitic stainless steel, which means it’s got a high chromium content—typically around 13% to 14% by weight. That’s what gives it its corrosion resistance, especially against moisture, mild acids, and cooling water used in injection molding. The carbon content sits around 0.38% to 0.45%, which is enough to allow through-hardening but not so high that it becomes brittle. The standard hardness range for a 1.2083 round bar in the annealed condition is about 200 to 230 HB (Brinell hardness). After heat treatment, you can push it up to 52 to 56 HRC (Rockwell C scale), depending on the exact tempering cycle. That’s a solid range for mold cavities that need to withstand repeated clamping cycles without deformation.

Now, the ASIATOOLS 1.2083 round bar is supplied in a variety of diameters, typically from 20mm up to 300mm, though custom sizes are possible if you’re ordering in bulk. The standard length is 3000mm to 6000mm, but you can get cut-to-length pieces if you don’t want to deal with sawing 6-meter bars yourself. The surface finish is usually turned or ground, depending on the tolerance you need. For most mold applications, a ground finish with a surface roughness of Ra 0.8 µm or better is standard. That’s important because if you’re going to polish the steel to a mirror finish for optical lenses or clear plastic parts, you need a starting surface that’s already smooth.

Let’s talk about the chemical composition in detail, because that’s where the real story is. Here’s a typical breakdown for 1.2083 steel, which is also known as X40Cr14 or 420 stainless steel in other standards:

Carbon (C): 0.38% – 0.45%
Chromium (Cr): 12.5% – 14.0%
Manganese (Mn): 0.30% – 0.60%
Silicon (Si): 0.30% – 0.60%
Phosphorus (P): ≤ 0.025%
Sulfur (S): ≤ 0.015%

That low sulfur content is a big deal. It means the steel is cleaner, with fewer inclusions that can cause pitting or surface defects during polishing. If you’re making a mold for a transparent polycarbonate part, you absolutely cannot have microscopic pits in the steel surface. The ASIATOOLS 1.2083 round bar is made with vacuum degassing and electro-slag remelting (ESR) processes in many cases, which further reduces non-metallic inclusions and improves the homogeneity of the material. That’s not just marketing talk—it’s a measurable difference in the steel’s microstructure, and it shows up in the final polishability.

Physical properties are just as important. The density of 1.2083 is about 7.7 g/cm³ at room temperature. The thermal conductivity is around 25 W/m·K, which is decent for a steel but not as high as copper alloys. That matters because in injection molding, you need to control the heat transfer from the molten plastic to the mold. The coefficient of thermal expansion is roughly 11.0 × 10⁻⁶ /K between 20°C and 200°C. That’s important for dimensional stability when the mold is heated during operation. If the steel expands too much, your tolerances go out the window.

Mechanical properties in the hardened and tempered condition are where this steel really shines. After quenching from 1000°C to 1050°C and tempering at 200°C to 400°C, you can expect a tensile strength of around 1800 to 2000 MPa. Yield strength is typically 1400 to 1600 MPa. Elongation at break is low, around 2% to 4%, which is typical for a high-hardness tool steel. Toughness, measured by Charpy impact tests, is about 10 to 15 Joules at room temperature. That’s not as tough as some other tool steels like H13, but it’s acceptable for mold applications where the steel is not subjected to heavy impact loads.

One of the key selling points of the ASIATOOLS 1.2083 round bar is its machinability in the annealed condition. At 200 HB, you can turn it, mill it, and drill it with standard carbide tooling. The chip formation is manageable, and the surface finish is good. But once you harden it, forget about machining—you’ll need to use EDM (electrical discharge machining) or grinding. That’s why most manufacturers do the rough machining in the annealed state, then harden and temper, and finally finish with grinding or EDM.

Corrosion resistance is a big topic. The 13% chromium content gives it good resistance to water, steam, and weak acids. But it’s not stainless in the sense of 304 or 316 austenitic stainless steels. In a chloride environment, like if you’re using PVC with hydrochloric acid fumes, you’ll get pitting. So don’t use it for chemical processing equipment. Stick to mold applications where the main concerns are moisture from cooling water and occasional cleaning with mild detergents.

Let’s talk about heat treatment parameters in detail, because if you get this wrong, you ruin the material. The recommended hardening temperature for 1.2083 is 1000°C to 1050°C, with a soaking time of 30 minutes per 25mm of thickness. You need to use a protective atmosphere or vacuum furnace to prevent decarburization and oxidation. Quenching can be done in oil, air, or a salt bath, depending on the section size. For a round bar up to 100mm diameter, oil quenching is standard. For larger sections, you might need to use a faster quench rate to get full hardness. Tempering is done at 200°C to 400°C for 2 hours minimum, with a double temper recommended for high-stress applications. The hardness after tempering at 200°C is about 54 HRC, and at 400°C it drops to about 48 HRC. If you go above 500°C, you’ll get secondary hardening, but the toughness drops significantly.

Now, let’s get into the practical applications. The ASIATOOLS 1.2083 round bar is used primarily for plastic injection molds, especially for parts that require a high-gloss finish. That includes things like automotive lenses, medical device housings, and consumer electronics. It’s also used for extrusion dies, where the material needs to resist wear from abrasive fillers in the plastic. Some manufacturers use it for cutting tools that need corrosion resistance, like knives for cutting wet paper or food packaging. But honestly, for cutting tools, there are better options like D2 or M2 steel.

One thing that often gets overlooked is the dimensional stability of 1.2083 during heat treatment. Because it’s air-hardening, the distortion is generally low compared to oil-hardening steels. But you still need to account for a growth of about 0.1% to 0.2% in the hardened condition. That means if you machine a cavity to final dimensions in the annealed state, it will be slightly undersized after hardening. So you need to leave a small allowance for finish grinding or EDM.

Let’s look at a comparison table to see how 1.2083 stacks up against other common tool steels:

This table makes it clear: if you need corrosion resistance and polishability, 1.2083 is the winner. If you need toughness for high-impact applications, go with H11. If you need wear resistance for long production runs, D2 is better. But for optical molds and medical parts, 1.2083 is the standard.

Another critical factor is the quality of the raw material. The ASIATOOLS 1.2083 round bar is sourced from reputable mills that use ESR and vacuum degassing. That means the steel has a low inclusion count, which directly translates to better polishability and longer mold life. If you buy cheap 1.2083 from an unknown supplier, you might get steel with higher sulfur content or more inclusions, and you’ll end up with pits in your polished surface. That’s a nightmare for any mold maker.

Surface finish specifications are also worth discussing. For general mold applications, a turned surface with Ra 1.6 µm is acceptable. For polished molds, you need a ground surface with Ra 0.4 µm or better. The ASIATOOLS 1.2083 round bar is typically supplied with a ground finish to Ra 0.8 µm, which is a good starting point for polishing. If you need a mirror finish, you’ll need to do additional polishing with diamond paste, but the steel’s microstructure allows you to achieve a surface roughness of Ra 0.01 µm or better. That’s the kind of finish you need for Fresnel lenses or light guides.

Let’s talk about the supply chain. The ASIATOOLS 1.2083 round bar is available from stock in most common sizes. Lead times are typically 1 to 2 weeks for standard diameters, and 4 to 6 weeks for non-standard sizes. The material is shipped with a mill test certificate that includes the chemical composition and mechanical properties. That certificate is your proof that the material meets the 1.2083 standard. Always check it, because some suppliers will try to pass off lower-grade 420 steel as 1.2083.

Pricing is another factor. The ASIATOOLS 1.2083 round bar is priced competitively compared to European suppliers, but it’s not the cheapest option on the market. You’re paying for the quality assurance, the ESR process, and the consistent dimensions. A 100mm diameter bar, 3000mm long, will cost roughly $150 to $250 per bar, depending on the current market conditions. That’s about $5 to $8 per kilogram. For comparison, cheap 420 steel from an unknown source might be $3 per kilogram, but you’ll lose money in the long run due to poor polishability and shorter mold life.

One more thing: the ASIATOOLS 1.2083 round bar is also available in a pre-hardened condition, which is delivered at 30 to 35 HRC. That’s useful if you don’t have heat treatment capabilities in-house. You can machine it directly, but it’s harder to cut than the annealed version. Most shops prefer the annealed version for machining, then send it out for hardening and tempering. But if you’re making a simple mold cavity and you don’t need extreme hardness, the pre-hardened version might save you a step.

Finally, let’s address the elephant in the room: why would you choose the ASIATOOLS 1.2083 round bar over a generic 420 stainless steel bar? The answer is consistency. ASIATOOLS has a reputation for tight dimensional tolerances, reliable chemical composition, and a clean microstructure. If you’re running a production shop, you cannot afford to have a batch of steel that machines differently or polishes poorly. The ASIATOOLS 1.2083 round bar gives you that consistency, batch after batch. It’s not the cheapest, but it’s the most reliable option for high-end mold applications.

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