Product Overview
Stainless steel round bars serve as foundational raw material for precision CNC machining, structural shafts, and corrosion-resistant fasteners in demanding industrial environments. Produced via hot rolling, cold drawing, or centerless grinding, our bars deliver consistent mechanical properties, tight dimensional tolerances, and uniform microstructures. Each production batch is fully compliant with international pressure equipment and structural standards, backed by verifiable material test reports (EN 10204 3.1).
Technical Specifications
|
Parameter |
Specification Range |
|
Standard Grades |
Austenitic: 304/304L, 316/316L, 310S, 321 Duplex: 2205 (S31803/S32205), 2507 Precipitation Hardening: 17-4PH (630) |
|
Diameter Range |
Cold Drawn: 3 mm - 50 mm Hot Rolled: 16 mm - 300 mm Peeled / Turned: 30 mm - 400 mm |
|
Length Options |
Standard 3m, 5800 mm, 6m, or custom cut lengths up to 12m |
|
Tolerance Classes |
h9, h11, h13, K12, or precision ground to ±0.02 mm |
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Surface Finish |
Acid Pickled, Cold Drawn Bright, Centerless Ground (CG), Polished (Ra <= 0.8 um) |
|
Execution Standards |
ASTM A276, ASTM A479, EN 10088-3, JIS G4303, ASME SA276 |
|
Compliance Directives |
PED 2014/68/EU compliant material options available for pressure-retaining components |
Product Advantages
Strict Chemical Composition Control:
Raw material melts adhere strictly to carbon, chromium, nickel, and molybdenum thresholds to prevent intergranular corrosion and ensure optimal pitting resistance equivalent (PREN) targets.
Machinability Stability:
Controlled sulfur additions (where applicable) and uniform thermal treatment minimize tool wear and dimensional distortion during high-speed CNC turning and milling operations.
Straightness & Ovality Control:
Advanced multi-roll straightening equipment maintains a camber deviation of <= 0.5 mm/m, eliminating eccentric vibration in high-RPM rotating shaft applications.
In-House Manufacturing Capacity:
Operating 12 hot-rolling lines and 6 cold-drawing benches allows direct mill-level control over reduction ratios, mechanical hardening rates, and annealing temperature curves.
Applications
Rotating Machinery: Pump shafts, high-speed drive shafts, and industrial agitator spindles requiring high torsional fatigue strength.
Fluid & Energy Control: Valve stems, ball valve cores, and flange fittings exposed to corrosive media in chemical processing and oil & gas streams.
Fastener Manufacturing: Heavy-duty bolts, studs, and anchor rods operating in marine or offshore environments.
Medical & Food Equipment: Surgical instrument blanks and precision conveyor rollers demanding cleanable, non-contaminating metallic surfaces.
Customization & Processing
High-speed industrial band saws execute precision cut-to-length services with length tolerances within ±1 mm, minimizing shop-floor preparation waste.
Surface defect removal via heavy-duty peeling machines and centerless grinders strips away decarburized layers and surface micro-fissures.
Solution annealing, stress relieving, and quench-tempering executed per client specification to fine-tune hardness, yield strength, and impact toughness.
Quality Control & Inspection
Spectrometer Analysis: Direct-reading optical emission spectrometers (OES) verify elemental composition on every heat lot prior to shop release.
Ultrasonic Testing (UT): 100% volumetric inspection available per ASTM A388 to detect internal voids, inclusions, or center porosity in critical structural bars.
Mechanical Testing: Tensile strength, yield strength, percentage elongation, and Brinell/Rockwell hardness tests performed routinely on certified universal testing machines.
Traceability Assurance: Heat numbers, grade codes, and manufacturer stamps are hard-punched or ink-jet marked along the bar length, cross-referenced directly to EN 10204 3.1 Mill Test Certificates. (Visual reference available on request for microstructural grain analysis reports).
Packaging & Shipping
Export-Grade Bundling:
Bundled in 1 ton to 2 ton units using high-tensile steel strapping, separated by wooden dunnage blocks to prevent transit bending.
Corrosion Defense:
Bars coated with a neutral anti-rust film; optional heavy-duty plastic sleeve wrapping or moisture-barrier woven fabric for ocean freight.
End Protection:
Heavy-duty plastic protection caps fitted on all bars with diameters above 50 mm to safeguard machined bevels and edges from impact. (Visual inspection photos of bundled cargo provided prior to container loading).
FAQ
Q: What is the standard minimum order quantity (MOQ) for non-stock stainless steel round bar sizes?
A: MOQ is 1 metric ton per size for custom rolling grades. For standard stock items in grades 304/304L and 316/316L, smaller trial orders or cut-to-size pieces are available upon request.
Q: Are EN 10204 3.1 Material Test Reports provided with the shipment?
A: Yes. Every shipment includes an official 3.1 certificate detailing actual chemical melt analysis, mechanical test results, and heat treatment parameters, fully traceable via the heat number marked on the bars.
Q: What is the difference in surface finish between cold drawn and centerless ground bars?
A: Cold drawn bars offer a bright, smooth finish with tight tolerance control (h9/h11) achieved through cold die reduction. Centerless ground bars completely eliminate surface defects, delivering superior straightness and precise roundness ideal for high-speed precision shafts.
Q: Can you supply material compliant with PED 2014/68/EU for pressure equipment?
A: Yes. We routinely supply material meeting European Pressure Equipment Directive requirements alongside comprehensive positive material identification (PMI) documentation.
Q: How do you protect stainless steel bars from surface corrosion during international sea freight?
A: Bars are coated with a protective anti-rust film, bundled securely, and wrapped in moisture-resistant woven polypropylene. Wooden dunnage is used inside dry-van containers to isolate cargo from floor condensation.
Q: What are your standard delivery lead times for stock versus custom production?
A: Ex-stock items ship within 5 to 7 business days. Custom rolling, peeling, or cutting orders typically require 25 to 35 days depending on mill scheduling and secondary processing complexity.
Request a Quote
Submit your technical requirements below to receive a formal commercial quotation including material cost, freight estimate, and an advance preview of the Mill Test Certificate.
Required Fields: Grade (e.g., 316L / 1.4404), Diameter (mm or inches), Length (mm), Quantity (Tons or Pieces), Destination Port, Target Standard (ASTM / EN / ASME).
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