What is stainless steel fabrication?

Characteristics and advantages of stainless steel in manufacturing

• Standard environments: Stainless steel does not oxidize or rust when exposed to air, rainwater, or high-humidity conditions.
• Harsh environments: Depending on the specific grade (such as 316 stainless steel), the material can resist corrosion from chemicals, acids, and sea salt.
• Long-term durability: Ensures that products maintain their structural integrity and surface quality over decades of use.

• Load-bearing & Impact Resistance: Stainless steel possesses significantly higher tensile stress and impact strength compared to standard carbon steels or aluminum.
• Mechanical Rigidity: This allows for the production of components capable of withstanding heavy loads and operating under conditions of high vibration or intense pressure without undergoing deformation.

• The natural surface of stainless steel possesses a sleek, lustrous sheen, lending an air of modern elegance and luxury.
• It offers versatile surface finishing options tailored to specific requirements, such as hairline (brushed) finishes, mirror-polished finishes, or textured (matte/frosted) finishes.
• It is perfectly suited for a wide range of applications, from industrial products to interior and exterior residential furnishings.

• Thanks to its excellent ductility (particularly in the austenitic stainless steel grade), this material can be easily cut, bent, formed, deep-drawn, and welded.
• It enables the fabrication of products ranging from simple to complex, in a wide variety of sizes.
• It is suitable for both custom, one-off production based on individual designs and large-scale, automated mass production.

• Stainless steel is an environmentally friendly material that is 100% recyclable at the end of its life cycle, without any loss of its original properties.
• Although the initial investment cost is higher than that of conventional iron or steel, the long-term costs for maintenance, servicing, and replacement are extremely low.

Types of stainless steel commonly used in mechanical machining

• Stainless Steel 304: The most widely used type in manufacturing; it offers good corrosion resistance, is easy to process, and is suitable for products that do not require high load-bearing capacity.
• Stainless Steel 316: Offers superior corrosion resistance and higher load-bearing capacity compared to 304; it is ideal for products that require high durability in highly corrosive environments.
• Stainless Steel 430: A relatively low-cost option with lower corrosion resistance than 304 or 316; it is commonly used for household products.
• Stainless Steel 201: Shares similar properties with 304 but is more cost-effective; it is used in both household and commercial products.

Common methods for processing stainless steel today

1. Stainless steel cutting processing

• Mechanical cutting: Involves the use of shears or circular saws. Suitable for straight cuts; it is a low-cost method, though relatively slow, and may leave burrs along the cut edge.
• CNC laser cutting: Currently the most advanced method. A focused, high-energy laser beam enables precise cutting of stainless steel, resulting in narrow, clean edges without thermal deformation or the need for secondary deburring.
• Plasma cutting: Ideal for thicker stainless steel plates (ranging from 10mm to several tens of millimeters). It offers high cutting speeds and is more cost-effective than laser cutting, though it produces a wider kerf (cut width) and a slight bevel.
• Waterjet cutting: Utilizes an ultra-high-pressure stream of water mixed with abrasive particles. It can cut stainless steel of any thickness without generating heat, ensuring the material's properties remain unaltered in the cut zone.

2. Stainless steel bending/forming

• Concept: A method that utilizes a CNC press brake to apply pressure to a stainless steel sheet, bending the workpiece into desired angles (e.g., 45°, 90°, 135°).
• Principle: The stainless steel sheet is positioned between a die and a punch. Hydraulic or electric force drives the punch down toward the die to form the bend.
• Applications: Manufacturing industrial machinery enclosures, electrical cabinets, drainage channels, cable trays, and box-frame shelving units.

3. Stainless steel bending processing

• Stainless steel pipe bending: Utilizing hydraulic pipe-bending machines or three-roller bending machines to shape round or square/rectangular pipes into arches, coils, or semi-circular forms.
• Stainless steel bar/plate bending: Shaping flat bars, as well as V- or U-profile sections, to the specific curvatures required by the technical drawings.
• Factors affecting precision: Material spring-back, the thickness of the plate or pipe, the bending radius (R), and the bending speed.

4. Stainless steel welding fabrication

• TIG (Argon) welding: The most common method for stainless steel fabrication. It produces clean, aesthetically pleasing welds and is ideal for thin stainless steel or applications requiring an absolute seal (such as storage tanks and piping).
• MIG welding: Offers high welding speeds and productivity; well-suited for thick stainless steel frame structures.
• Laser welding: A modern technology characterized by minimal heat input, resulting in ultra-fine welds without causing workpiece deformation or discoloration (blackening) of the weld area.
• Shielded metal arc welding (stick welding): Used for outdoor projects or thick structures where it is difficult to transport shielding gas equipment.

5. CNC turning and milling of stainless steel

• Stainless steel turning: Machining rotational components such as shafts, bushings, flanges, and threaded parts.
• Stainless steel milling: Creating grooves, flat surfaces, pockets, gears, or complex, multi-faceted mechanical components.
• CNC technology application: Automates the turning/milling process, ensuring extremely tight tolerances (down to the micron level) and a perfectly smooth surface finish.

6. Stainless steel stamping/punching

• Stainless steel punching: Creating round, oval, or square holes on the surface of stainless steel sheets (e.g., for perforated metal sheets or cable trays).
• Forming (stamping): Using dies to emboss, deboss, or shape sheet metal components in large quantities within a short timeframe.

7. Polishing and surface treatment of stainless steel

• Mechanical polishing: Using felt, polishing pads, and specialized compounds to smooth the surface.
• Hairline finishing: Creating fine, uniform, linear scratch patterns (highly popular for elevator interiors and high-end home appliances).
• Mirror polishing: Achieving a highly reflective, mirror-like finish on stainless steel surfaces (such as BA or 8K grades).
• Weld discoloration removal: Using chemical agents (specialized pastes or acidic solutions) or an electrolytic weld-cleaning machine to remove the black oxidation marks (heat tint) that occur during TIG/MIG welding.
• Surface passivation: Immersing the metal in or spraying it with a citric or nitric acid solution to restore the protective chromium oxide layer that may have been compromised during fabrication.

 

Professional 7-step stainless steel processing workflow

• Step 1: Requirement Intake & Consultation: Receiving technical drawings or physical samples from the client; analyzing the intended use to advise on the appropriate stainless steel grade (e.g., 201, 304, 316), material thickness, and the most cost-effective fabrication method.
• Step 2: Design & Drawing Breakdown: Analyzing technical specifications, creating CAD/CAM drawings, calculating material requirements (sheets/tubes), and programming CNC machinery.
• Step 3: Material Selection & Inspection: Selecting stainless steel of the correct grade, verifying thickness and surface finish (e.g., 2B, No.1, BA, HL), and cross-referencing CO/CQ (Certificate of Origin/Quality) documentation when required.
• Step 4: Fabrication: Cutting raw materials (via Laser or Plasma) ➔ Bending/Forming ➔ Welding and structural assembly ➔ Secondary mechanical processing (turning, milling, punching).
• Step 5: Surface Treatment & Finishing: Grinding welds smooth, removing weld discoloration, polishing or applying a hairline finish, and passivating the surface.
• Step 6: Quality Control (QC): Verifying actual dimensions against drawings, checking tolerances, testing weld integrity (using pressure or dye-penetrant testing), and evaluating surface flatness and overall aesthetics.
• Step 7: Packaging & Delivery: Applying protective PE film to prevent surface scratches, securing items with cardboard or wooden crates, and arranging delivery to the client’s location.

Common stainless steel fabricated products today

• Stainless steel tanks: Domestic water storage tanks, pressure vessels, chemical mixing tanks, and sanitary/bioprocessing tanks for the pharmaceutical and food industries.
• Stainless steel frames & structures: Industrial machine frames, load-bearing supports, structural frameworks for workshops, and architectural/decorative metalwork.
• Conveyor & transport systems: Stainless steel conveyor frames, rollers, and feed chutes for seafood and agricultural produce processing plants.
• Stainless steel electrical enclosures & equipment housings: Outdoor electrical cabinets, waterproof control panels, and protective housings for mechanical machinery.
• Commercial & industrial stainless steel equipment: Industrial workstations, three-compartment sinks, utility carts, and kitchen exhaust hood systems.
• Precision CNC-machined components: Machine shafts, bushings, couplings, flanges, and medical device components.

Widespread applications of stainless steel processing in various industries

• Food & Beverage (F&B) Industry: Requires absolute hygiene. 304/316-grade stainless steel is used for processing equipment—such as that for dairy, beer, and soft drinks—as well as for food trays, due to its chemical inertness and ease of cleaning.
• Pharmaceutical & Medical Industry: 316L-grade stainless steel is utilized for pharmaceutical mixing tanks, operating tables, surgical instruments, and storage cabinets for biological samples, thanks to its high resistance to bacteria and suitability for sterile environments.
• Construction & Architecture: Used for stainless steel and glass staircases, railings, gates, and building facade cladding, providing a modern aesthetic while remaining resistant to weather-related damage.
• Mechanical Engineering & Manufacturing: Used for machine housings, load-bearing mechanical components, and protective equipment guards.
• Chemical & Environmental Industry: Used for the fabrication of chemical pipelines, exhaust gas treatment towers, and tanks for biological wastewater treatment.
• Logistics & Warehousing: Used for heavy-duty storage racking systems, automated sorting conveyor belts, and internal transport carts.

Quality inspection processes for stainless steel fabricated products

• Thickness inspection: Verifying that the material thickness is appropriate to achieve high precision during fabrication, typically using specialized metal thickness gauges.
• Gloss/finish inspection: Utilizing gloss-measuring instruments to evaluate the surface finish and ensure it meets specified requirements.
• Dimensional accuracy inspection: Using precision measuring tools—such as micrometers and calipers—to verify dimensions.
• Durability/strength testing: Employing methods such as tensile testing or flexural (bending) testing to assess structural integrity.
• Surface brightness inspection: Using specialized equipment to measure the brightness or reflectivity of the stainless steel surface.
• Corrosion resistance testing: Conducting assessments such as electrochemical corrosion testing.
• Weld inspection: Evaluating the integrity and strength of welds using dedicated testing equipment, as well as methods like visual inspection or acoustic/sound-based testing.

Factors affecting the quality of processed stainless steel products

• Raw material quality: High-quality stainless steel results in high-quality finished products.
• Thickness and dimensions: These are critical factors; if they do not meet the specified requirements, the quality of the product will be compromised.
• Manufacturing technology: The use of advanced, modern production technologies—which optimize manufacturing processes and increase productivity—directly impacts product quality.
• Skills and experience of production staff: These play a vital role in ensuring the quality of the final product.
• Quality management: This is essential for maintaining product quality. Rigorous and accurate quality inspection processes must be consistently implemented.
• Production environment: The working environment affects product quality; substandard conditions can lead to manufacturing defects and a decline in product quality.
• Storage and transportation conditions: How the processed stainless steel products are stored and transported also influences their final quality.

What factors determine the price for stainless steel fabrication?

• Quality and thickness of the stainless steel: Costs increase when using higher-quality or thicker stainless steel.
• Product dimensions and complexity: Larger or more complexly shaped products are more expensive to produce than simpler ones.
• Fabrication methods: Different techniques—such as plasma cutting, laser cutting, CNC machining, welding, grinding, or polishing—carry different costs.
• Quantity: The total volume of items being fabricated also influences the price; generally, higher quantities lead to lower production costs per unit.
• Location and market: The location of the order and the target market play a role. The location affects shipping costs, while the specific market influences competitive pricing.

What is the cost for 304 stainless steel fabrication?

Intech Mechanical specializes in custom stainless steel fabrication in Hanoi.