We furnish stainless steel square bar in precision‑cut lengths, tailored to exacting tolerances and engineered to perform under the harshest environments. We control every step—from alloy formulation to final inspection—so you receive a product that meets your most stringent demands without compromise.
Chemical Composition (wt% – ASTM A276 Standard)
| Element | 304/304L | 316/316L | 303 | 410 | 430 |
|---|---|---|---|---|---|
| Chromium (Cr) | 18.0–20.0 | 16.0–18.0 | 17.0–19.0 | 11.5–13.5 | 16.0–18.0 |
| Nickel (Ni) | 8.0–12.0 | 10.0–14.0 | 8.0–10.0 | ≤0.75 | ≤0.75 |
| Carbon (C) | ≤0.08 (0.03L) | ≤0.08 (0.03L) | ≤0.15 | 0.08–0.15 | ≤0.12 |
| Manganese (Mn) | ≤2.00 | ≤2.00 | ≤2.00 | ≤1.00 | ≤1.00 |
| Silicon (Si) | ≤1.00 | ≤1.00 | ≤1.00 | ≤1.00 | ≤1.00 |
| Phosphorus (P) | ≤0.045 | ≤0.045 | ≤0.20 | ≤0.040 | ≤0.040 |
| Sulfur (S) | ≤0.030 | ≤0.030 | ≥0.15 | ≤0.030 | ≤0.030 |
| Molybdenum (Mo) | – | 2.00–3.00 | – | – | – |
| Iron (Fe) | Balance | Balance | Balance | Balance | Balance |
Notes:
303: Enhanced machinability (S added)
L Grades: Lower carbon for welding (304L/316L)
410: Martensitic; 430: Ferritic
Mechanical Properties (Annealed Condition)
| Property | 304/304L | 316/316L | 303 | 410 | 430 |
|---|---|---|---|---|---|
| Tensile Strength | 515 MPa (75 ksi) | 515 MPa (75 ksi) | 620 MPa (90 ksi) | 480 MPa (70 ksi) | 450 MPa (65 ksi) |
| Yield Strength (0.2%) | 205 MPa (30 ksi) | 205 MPa (30 ksi) | 240 MPa (35 ksi) | 275 MPa (40 ksi) | 205 MPa (30 ksi) |
| Elongation (%) | 40 | 40 | 50 | 20 | 22 |
| Hardness (Max) | 95 HRB | 95 HRB | 100 HRB | 25 HRC | 89 HRB |
| Density (g/cm³) | 7.93 | 7.98 | 7.93 | 7.70 | 7.70 |
Standard Sizes & Weights
Common Dimensions (ASTM A484)
| Size (mm) | Size (inches) | Weight 304 (kg/m) | Weight 316 (kg/m) | Standard Lengths |
|---|---|---|---|---|
| 5×5 | 0.20×0.20 | 0.198 | 0.200 | 3m, 6m, 12ft |
| 10×10 | 0.39×0.39 | 0.793 | 0.798 | 3m, 6m, 12ft |
| 12×12 | 0.47×0.47 | 1.142 | 1.149 | 3m, 6m, 20ft |
| 16×16 | 0.63×0.63 | 2.029 | 2.043 | 3m, 6m, 20ft |
| 20×20 | 0.79×0.79 | 3.172 | 3.192 | 3m, 6m, 20ft |
| 25×25 | 1.00×1.00 | 4.956 | 4.988 | 3m, 6m, 20ft |
| 30×30 | 1.18×1.18 | 7.137 | 7.182 | 6m, 20ft |
| 40×40 | 1.58×1.58 | 12.688 | 12.768 | 6m, 20ft |
| 50×50 | 2.00×2.00 | 19.825 | 19.950 | 6m, 20ft |
| 60×60 | 2.36×2.36 | 28.548 | 28.728 | Custom |
Weight Calculation Formulas
Metric (kg/m) = (Width²) × Density × 0.001 Imperial (lb/ft) = (Width²) × Density × 0.0833
Example (304, 20mm bar):
(20²) × 7.93 × 0.001 = 3.172 kg/m
(0.79²) × 0.286 × 12 = 2.14 lb/ft
Key Grades & Applications
| Grade | Type | Primary Uses |
|---|---|---|
| 304 | Austenitic | Fasteners, architectural trim, food equipment |
| 316 | Austenitic | Marine hardware, chemical processing, medical |
| 303 | Free-Machining | Shafts, valves, fittings (high-speed CNC) |
| 410 | Martensitic | Cutlery, tools, pump shafts (heat-treatable) |
| 430 | Ferritic | Automotive trim, appliances, nitric acid tanks |
Technical Notes
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Tolerances: Per ASTM A484 (Size: ±0.1mm to ±1% | Straightness: ≤0.5mm/m).
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Surface Finishes:
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Hot Rolled: Scaled or Pickled.
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Cold Finished: Bright (Polished/Ground).
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International Equivalents:
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EU: 304=1.4301, 316=1.4401, 303=1.4305.
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Japan: SUS304, SUS316, SUS303.
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China: 0Cr18Ni9 (304), 0Cr17Ni12Mo2 (316).
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Certification: Mill Test Reports (MTR) available for traceability.
Global Price Comparison
| Region | Price Range (USD/kg) | Price Range (USD/tonne) | Notes |
|---|---|---|---|
| China | $2.18–2.38 /kg (bulk) | — | MWalloys offer for 304/316 SS square bar, scales: 1–24 t at $2.38/kg, 25–99 t at $2.18/kg |
| United States | $1.00–2.50 /kg | $1,800–2,300 /tonne | Typical ASTM A276 prices range from $1,000–2,500/tonne; equivalent to ~$1–2.50/kg |
| India | $1–5 /kg | $4,900–5,000 /tonne | Polished 304 ASTM A276 H9 tolerance listed at $4,900–5,000/tonne (~$4.9–5.0 /kg) |
| Europe | $1.55–4.50 /kg | $1,550–3,000 /tonne | FOB prices range from $1,550–3,000/tonne (~$1.55–3.00/kg) |
Key observations:
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China offers highly competitive bulk-tier pricing: US $2.18–2.38/kg (~US $2,180–2,380/tonne) for 304/316 grades.
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US prices vary significantly: general stainless bar $1–2.50/kg, A276-specific $1,800–2,300/tonne (~$1.8–2.3/kg) .
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India shows a wide local price span ($1–5/kg), with more precise polished 304 bars at ~$4.9/kg.
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Europe levels out in the $1.55–4.50/kg range, equivalent to $1,550–3,000/tonne.
📊 Summary
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Lowest floor price in the U.S. at ~$1/kg; highest ceiling in India at ~$5/kg.
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China provides solid bulk discounts, particularly over 25 tonne orders.
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Europe and the U.S. fall in the mid-range bracket, $1–2.5/kg.
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India displays the widest pricing range due to varied finishes and quality tiers.
Comparison: Square Bar vs. Other Profiles
We often compare square bar with round rod and flat bar.
| Profile | Edge Definition | Machinability | Weight per m (kg) at 20 × 20 mm | Typical Use |
|---|---|---|---|---|
| Square bar | Sharp corners | High | 2.50 | Framework, chisels, connectors |
| Round rod | Uniform stress | Moderate | 2.50 | Shafts, pins, fasteners |
| Flat bar | Large surface | Very high | 1.60 at 50 × 10 mm | Brackets, supports, decorative trim |
Typical Applications Across Industries
From chemical plants to architectural facades, square bar excels. In food processing, 316L resists wash‑down. In construction, 304 lends both strength and aesthetic. Government infrastructure projects often specify stainless for longevity—fewer replacements over 50 years.
Fabrication, Welding, and Machining Tips
We recommend TIG welding with ER 308 or ER 316L wire. Preheat if thickness > 10 mm. For machining, carbide tooling at 300 m/min cutting speed; coolant flow prevents work‑hardening. Incidentally, “measure twice, cut once” still holds.
Compliance with International Standards
Our bars conform to:
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ASTM A276/A484
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EN 10088
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DIN 17440
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JIS G4305
Each batch ships with a mill test certificate (MTC), traceable to raw‑material lot and heat number—nothing left to chance.
Environmental Sustainability and Recycling
We reclaim 100 % of off‑cuts. Stainless scrap is infinitely recyclable without performance loss. Consequently, using our bars reduces carbon footprint—an environmentally responsible choice that pays off in the long run.
Packaging, Storage, and Delivery
We bundle lengths with corrosion‑inhibiting paper, cap ends, and secure in wooden crates. Transit damage is rare: our on‑time delivery rate exceeds 98 %.
Frequently Asked Questions
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How do you verify the chemical composition of your stainless steel square bar?
We perform spectrographic analysis on every heat lot. Only when the alloy falls within the specified ranges (per ASTM A276) do we proceed to rolling and cutting. -
Can MWaolloys customize bar dimensions beyond standard profiles?
Absolutely. Whether you need 5 × 5 mm or 150 × 150 mm, we’ll tailor the cross‑section and length to your exact requirements—no minimum order restrictions on custom sizes. -
What post‑production treatments do you offer?
We provide bright annealing, pickling, and passivation (ASTM A967) to enhance corrosion resistance and achieve the surface finish you demand—matte or reflective. -
How long is the typical lead time for a large order?
For standard grades (304/316L), our lead time is 2–3 weeks for orders up to 50 tonnes. Urgent requests? We often expedite smaller runs within 7 days. -
What measures ensure the straightness and flatness of each bar?
We use high‑precision straightening machines and conduct optical flatness checks (≤ 0.2 mm deviation per meter). This process minimizes material waste and machining time on your end. -
Do you offer full traceability for your stainless steel square bar?
Yes. Each bundle includes a mill test certificate showing heat number, chemical report, mechanical properties, and compliance with ISO 9001:2015. You’ll always know exactly where your material originated.
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