Stainless Steel is the material of choice when corrosion resistance, high tensile strength, and hygiene are non-negotiable. At Jucheng Precision, we have extensive experience machining various grades, from the versatile 304/316L to the hardened 17-4PH. Machining stainless steel requires rigid equipment to prevent work hardening. We utilize high-torque Haas and Mazak CNC centers to machine complex geometries with superior surface finishes. Our ISO 13485 certification specifically qualifies us to manufacture surgical instruments and medical implants where material purity and traceability are critical. We also offer passivation and electropolishing to maximize corrosion resistance.
The "Free-Machining" standard. Added sulfur allows for extremely fast turning speeds and extended tool life, making it the most cost-effective choice for high-volume fasteners, bushings, and shafts. While it has lower corrosion resistance than 304, its production efficiency for screw-machined parts is unmatched.
The universal "18/8" stainless. It offers excellent corrosion resistance, formability, and weldability. 304L (Low Carbon) prevents weld decay. It is the global standard for food processing equipment, industrial piping, and sanitary fittings where durability, hygiene, and chemical resistance are critical.
The premium choice for harsh environments. Containing Molybdenum, it offers superior resistance to chlorides (saltwater) and acids compared to 304. It is essential for ISO 13485 medical implants and surgical tools, as well as marine hardware exposed to aggressive seawater conditions.
An aerospace-grade precipitation-hardening steel. It combines high tensile strength with good corrosion resistance. It can be heat-treated (aged) to various conditions (like H900) to maximize hardness. Ideal for structural aircraft parts, pump shafts, and high-stress mechanical components requiring minimal distortion.
The most machinable of all stainless steels. This martensitic, magnetic alloy can be hardened by heat treatment to increase strength. It is widely used for electric motor shafts, gears, and solenoids where high production speed, magnetic permeability, and moderate corrosion resistance are required.
Known as "Cutlery Grade" or "Mold Steel," this high-carbon alloy offers good hardness (50 HRC) and wear resistance when heat-treated. It polishes to a high mirror finish, making it the preferred choice for plastic injection mold cavities, shear blades, and surgical instruments.
The hardest standard stainless alloy, capable of achieving 60 HRC after heat treatment. Often called "Bearing Steel," it offers extreme wear resistance and fatigue strength. It is the primary material for rolling element bearings, high-pressure valve seats, and premium cutting tools.
A high-strength mix of austenite and ferrite. It offers twice the yield strength of 316 and superior resistance to Stress Corrosion Cracking (SCC) and pitting. Ideally suited for the Oil & Gas and desalination industries, handling high pressure and aggressive chemical environments.
| Grade | Common Name | Key Characteristics | Typical Applications |
|---|---|---|---|
| SS 303 | Free-Machining Steel | Added sulfur makes it the easiest stainless to machine. Lower corrosion resistance than 304. | Nuts, bolts, bushings, fittings, shafts not exposed to harsh elements. |
| SS 304 / 304L | 18/8 Stainless | The most common grade. Excellent corrosion resistance, good formability. Harder to machine than 303. | Kitchen equipment, industrial piping, architectural panels, automotive trim. |
| SS 316 / 316L | Marine Grade | Contains Molybdenum for superior resistance to chlorides and acids. Biocompatible. | Medical implants, marine hardware, chemical processing equipment. |
| 17-4 PH | Precipitation Hardening | Can be heat treated to high hardness/strength. Good corrosion resistance. Magnetic. | Aerospace structural parts, turbine blades, molding dies. |
| SS 420 | Cutlery Grade | Martensitic steel with high hardness. Good wear resistance but lower corrosion resistance. | Surgical instruments, knife blades, shear blades, needle valves. |
| SS 416 | Free-Machining Martensitic | Easy to machine, high hardness capable. Lower corrosion resistance. | Motor shafts, pump parts, gears, valve components. |
| Capability | Technical Description | Jucheng Advantage |
|---|---|---|
| High-Torque Milling | Using rigid CNC machines with high torque at low RPM to cut tough stainless steel without chatter. | Our heavy-duty Mazak machines prevent vibration, ensuring smooth finishes even on hard grades like 17-4PH. |
| Swiss-Style Turning | Sliding headstock machining for long, slender stainless steel parts like medical pins and shafts. | Capable of holding tolerances of +/- 0.005mm for high-precision ISO 13485 medical components. |
| Hard Metal Machining | Processing heat-treated stainless steels (up to HRC 45) using specialized carbide tooling and coatings. | Eliminates the need for post-machining grinding in many applications, reducing costs. |
| Surface Passivation | Chemical treatment (Nitric or Citric acid) to remove free iron and enhance the natural oxide layer. | In-house handling ensures parts meet ASTM A967 standards for maximum corrosion resistance. |
Tooling Selection:
Stainless steel tends to “work harden” if cut improperly. We use premium coated carbide tools (TiAlN coating) with sharp cutting edges to shear the material cleanly rather than plowing through it.
Coolant Strategy:
Due to low thermal conductivity, heat stays in the cut. We employ high-pressure flood coolant to dissipate heat rapidly, preventing thermal expansion and extending tool life.
Feed Rates & Speeds:
It is critical to maintain a constant feed rate. Dwelling or rubbing allows the material to harden instantly, destroying the tool. We optimize tool paths to keep the cutter engaged and moving.
Rigidity:
Workholding must be extremely rigid. Any vibration can lead to poor surface finish and tool failure. We use hydraulic vices and custom fixtures to secure stainless steel parts firmly.
Medical Devices (ISO 13485 Certified)
Key Parts: Surgical scalpels, bone screws, implants, dental instruments.
Why Stainless Steel: Grades like 316L and 17-4PH offer biocompatibility, sterilization resistance, and high strength.
Food & Beverage Processing
Key Parts: Mixing blades, valves, conveyor components.
Why Stainless Steel: The smooth, non-porous surface of 304/316 prevents bacterial growth and withstands harsh cleaning chemicals.
Marine & Oil/Gas
Key Parts: Undersea valves, fasteners, sensor housings.
Why Stainless Steel: 316L provides excellent resistance to chloride (saltwater) corrosion and pitting in harsh environments.
Aerospace
Key Parts: Actuators, landing gear components, structural fittings.
Why Stainless Steel: Precipitation-hardening grades (17-4PH) deliver high strength-to-weight ratios and heat resistance.
| Density | 7.7 - 8.0 g/cm³ |
| Tensile Strength | 515 - 1300 MPa |
| Yield Strength | 205 - 1170 MPa |
| Elongation at Break | 10 - 60 % |
| Elastic Modulus | 190 - 210 GPa |
| Hardness | 80 HRB - 45 HRC |
| Thermal Conductivity | 12 - 24 W/m-K |
| Electrical Conductivity | 2 - 3 % IACS |
| Melting Point | 1370 - 1450 °C |
| Max. Part Size | 2000 mm (L) x 800 mm (W) x 600 mm (H) |
