Steel is an iron–carbon alloy with carbon content typically between 0.02% and 2.14%. Small amounts of elements such as chromium, nickel, molybdenum, or vanadium are often added to improve hardness, corrosion resistance, and strength. It is a versatile metal that is widely used in manufacturing, construction, and industrial applications.
3ERP is a leading provider of steel prototyping services, delivering precision machined steel parts through advanced CNC milling, turning, drilling, and surface finishing. With expertise in carbon steel, stainless steel, alloy steel, and tool steel machining, 3ERP ensures tight tolerances, excellent durability, and reliable performance for industries such as automotive, aerospace, medical devices, and industrial equipment.
Low carbon steels 1215 and 1018 are easy to machine, weld, and form, making them cost-effective for CNC machining. Mild steel is commonly used in fixtures, automotive components, and general-purpose parts.
1045 medium carbon steel offers greater strength and toughness compared to 1018, while still maintaining good machinability. It is widely used for shafts, gears, bolts, and other mechanical components that require higher wear resistance and durability.
Other widely used medium carbon steels include 1145F, which is quenched to improve machinability, and 11L41, alloyed with sulfur and lead to enhance cutting performance.
High carbon steel like 1095 is very hard and wear-resistant, especially after heat treatment. It is often selected for cutting tools, springs, and high-strength components that demand superior hardness and edge retention.
4140, also known as 42CrMo4, is a versatile alloy steel valued for its high strength, toughness, and fatigue resistance. It is widely used in aerospace, oil & gas, and automotive industries for critical parts such as shafts, axles, and fasteners.
4340 is a low-alloy metal providing excellent toughness, wear resistance, and high tensile strength, even under heavy loads. It is often chosen for demanding applications such as heavy-duty gears, shafts, and structural components that require superior durability.
O1 (oil-hardening), A2 (air-hardening), and D2 (high-carbon, high-chromium) tool steels are very hard and highly wear-resistant after heat treatment. They are commonly used for dies, molds, cutting tools, and other applications requiring long-term dimensional stability and durability.
*D2 has very high hardness (600–700 HB) after quenching and tempering, making it ideal for extreme wear resistance.
H13 tool steel offers excellent heat resistance and toughness, making it ideal for hot work tooling, die casting molds, and components exposed to high thermal stress.
Steel is prone to oxidation due to its iron content, so surface treatments are often applied for long-term durability. 3ERP provides full CNC machining services with optional secondary processes—such as surface finishing, coating, spraying, and heat treatment—to improve both the appearance and performance of steel parts.
Heat treatment modifies the internal structure of steel to enhance hardness, strength, and wear resistance. Common processes include quenching, tempering, annealing, carburizing, and nitriding. This ensures your machined parts perform reliably under demanding conditions.
Coating provides additional protection and improves the visual appeal of steel parts. For mild steel surface finishes, coating is essential since mild steel is prone to rust. Options include galvanizing, powder coating, electroplating, and paint, all of which enhance corrosion resistance and wear performance.
Spraying or thermal spray deposits a thin layer of metal, ceramic, or carbide on the part’s surface. It significantly improves wear resistance, corrosion resistance, and thermal stability. This process is especially useful for molds, dies, and high-temperature components.
Passivation or chemical treatment cleans and strengthens the protective oxide layer on stainless steel surfaces. It enhances corrosion resistance and prolongs the lifespan of critical components.
Blasting removes burrs, oxidation, and surface impurities while creating a uniform texture. Sandblasting, bead blasting, or shot peening can prepare surfaces for coatings or improve aesthetics. It’s an effective way to achieve consistent, clean finishes on machined parts.
Steel can range from relatively easy to machine to quite challenging, depending on the type of steel and its specific alloy content.
Easy to machine: Low carbon steels (like 1018, 1215) are soft and straightforward to machine.
Hard to machine: High carbon steels (e.g., 1095) and tool steels (like D2, A2) are harder and more challenging to machine, often requiring specialized tools and slower machining speeds.
In general, steel alloys with higher hardness or more complex compositions can be more challenging to machine, requiring advanced techniques like heat treatment, coating, and cooling to maintain performance and extend tool life.
Standard tolerances: For most steel CNC machined parts, a standard tolerance of ±0.05 mm (±0.002 in) is sufficient and cost-effective.
High precision machining: When required, 3ERP can achieve tolerances as tight as ±0.01 mm (±0.0004 in) on steel components using advanced 5-axis CNC equipment and proper process control.
Precision vs. cost: Higher precision often means longer machining times, stricter quality control, and higher production costs. We recommend choosing tolerances based on the actual function and application of the part to balance performance and budget.
CNC steel machining costs mainly depend on:
Steel material: Low-carbon steel is cheaper, while alloy or stainless grades cost more.
Parts setup: Each new design requires programming and tooling. Setup costs are fixed, so small batches are more expensive per part, while larger runs lower the unit price.
In general, simple steel parts in bulk can be $20–$50 each, while complex, high-precision parts may reach $100–$500 or more. For accurate pricing, request a custom quote from 3ERP.
