Kuaima Steel 304 SS Coil Cold Rolled ASTM A240 2026 Guide

2026-04-15 0 views

Kuaima Steel 304 SS Coil Cold Rolled ASTM A240 2026 Guide

Kuaima Steel Co., Ltd. supplies 304 stainless steel coil in cold-rolled, annealed condition to ASTM A240, covering a thickness range of 0.3–3.0mm, with a USD 3,000,000 platform deposit backing every transaction. Audited and holding Diamond Member status since 2020 across 12 product lines, Kuaima Steel provides mill test certificates, confirmed MOQ parameters, and traceable heat numbers—giving shortlisting buyers the verified data needed to move from spec comparison to formal inquiry.

Market Overview

Cold-rolled and annealed 304 stainless steel coil — produced to ASTM A240 with a thickness range of 0.3–3.0 mm — occupies the precision-flat-rolled segment of the stainless steel market, where dimensional consistency and surface finish directly determine suitability for food processing equipment, chemical containers, and architectural trim. Shandong Province is one of China's most concentrated steel-production corridors, home to large-capacity EAF and cold-rolling lines that supply both domestic fabricators and export markets routed through Qingdao and Rizhao ports. Within that geography, Kuaima Steel Co., Ltd. operates as a platform-audited, Diamond Member supplier carrying a USD 3,000,000 platform security deposit — a verifiable financial commitment that distinguishes it from unaudited trading intermediaries listing similar SKUs.

Standard coverage: ASTM A240, EN 10088-2, JIS G4305, and GB/T 3280 — four concurrent certifications that allow a single coil order to satisfy US, European, Japanese, and Chinese procurement specifications simultaneously.
Third-party inspection: Pre-shipment verification is available through SGS, Bureau Veritas (BV), Intertek, and TUV Rheinland, with mill test certificates (MTC) and CIQ Certificates issued per EN 10204 requirements.
2026 trade context: The EU Carbon Border Adjustment Mechanism (CBAM) phased rollout is beginning to affect carbon-intensity documentation requirements for steel imports into Europe, making supplier auditability and traceable MTCs more commercially significant than in prior years.
Price corridor: Across 12 listed variants, indicative pricing runs USD 1,200–2,440 per ton, with a 1-ton sample MOQ and a standard commercial MOQ of 20 tons (one 20FT container) on FOB Qingdao terms.

Buyers shortlisting cold-rolled 304 coil in 2026 are navigating a market where supplier transparency — audit status, deposit-backed platform membership, multi-standard compliance — carries as much weight as the base price per ton.

Key Industry Trends (2026–2030)

What is driving demand for cold-rolled 304 stainless steel coil?

Food processing equipment, chemical containment vessels, and architectural cladding are the three downstream sectors generating the most measurable pull for cold-rolled 304 coil in the 0.3–3.0 mm thickness range. Fabricators in these verticals specify ASTM A240 and EN 10088-2 compliance as a baseline, not a differentiator, which compresses the shortlist to mills and trading houses that can deliver certified material test certificates (MTC) and CIQ Certificates alongside every shipment.

Demand pressure is also coming from the Gulf Cooperation Council, where food-safety regulations now require 304 / UNS S30400 or better for food-contact surfaces, and from Southeast Asian pharmaceutical packaging lines upgrading from carbon steel to austenitic grades. MOQs as low as 1 ton on spot orders are becoming a commercial expectation in these markets.

Food processing lines increasingly mandate ≥515 MPa tensile strength and ≤0.08% carbon to meet hygiene traceability standards.
Architectural trim projects in the Middle East specify 2B and BA surface finishes, driving width orders across the 1000–2000 mm range.
Chemical container fabricators require EN 10204 3.1 mill test reports and third-party inspection by SGS or Bureau Veritas before shipment release.
India's BIS certification requirements for imported stainless flat products are tightening the qualification window for non-certified suppliers.

How are supply dynamics shaping the cold-rolled 304 coil market?

Spot prices for cold-rolled 304 coil currently range from USD 1,200 to USD 2,440 per ton depending on surface finish, thickness, and order volume, with mirror 8K and BA finishes commanding a 15–30% premium over standard 2B.

The EU Carbon Border Adjustment Mechanism (CBAM) phased rollout is adding an embedded carbon reporting obligation for European importers of Chinese stainless coil, while ongoing US Section 232 tariff reviews continue to redirect some Chinese export volume toward Middle Eastern and African markets. Suppliers holding a USD 3,000,000 platform security deposit signal a level of financial commitment that buyers in these redirected markets are increasingly using as a pre-qualification filter.

CBAM compliance requires exporters to document Scope 1 emissions per ton — a new documentation layer alongside the Commercial Invoice and Packing List.
Typical MOQ of 20 tons (one 20FT container) aligns with FOB Qingdao pricing and keeps per-unit freight costs manageable for mid-volume buyers.
Red Sea disruptions are adding 10–14 days to Europe-bound shipments, pushing Mediterranean transit times to 30–40 days via Cape of Good Hope rerouting.
Payment terms structured as 100% irrevocable L/C at sight through ICBC or Bank of China remain the standard risk-mitigation mechanism for first-time transactions.

Which process standards and verification steps matter most for 304 coil procurement?

ASTM A240, EN 10088-2, JIS G4305, and GB/T 3280 are the four standards that collectively cover the chemical composition, mechanical property, and dimensional tolerances buyers must cross-reference before issuing a purchase order for 304 coil.

Beyond the standards themselves, the verification workflow — from mill test certificate review to pre-shipment inspection — determines whether the coil received matches the coil ordered. Intertek and Bureau Veritas offer third-party chemical and mechanical verification at Chinese ports including Qingdao and Rizhao, providing an auditable chain of custody that satisfies both European CBAM reporting and Indian BIS import documentation requirements.

Verify Cr content sits within 18.0–20.0% and Ni within 8.0–10.5% against the EN 10204 3.1 MTC before approving shipment release.
Confirm hardness does not exceed 201 HBW / 92 HRB — a critical acceptance criterion for coil destined for deep-drawing or roll-forming operations.
Request a Certificate of Origin (COO) alongside the Bill of Lading to satisfy preferential tariff documentation in destination markets.
Cold-rolling and annealing process records should confirm the EAF or BOF melt route for traceability under CBAM carbon-reporting obligations.

Material Grades and Technical Specifications

Grade 304 stainless steel coil — cold rolled and annealed to ASTM A240 — is defined by a precise chemical envelope: 18.0–20.0% chromium, 8.0–10.5% nickel, carbon capped at ≤0.08%, manganese at ≤2.0%, and silicon at ≤1.0%. These boundaries are not arbitrary; the chromium-nickel balance is what establishes the austenitic microstructure responsible for the grade's passive oxide layer, which resists corrosive attack in food processing environments, chemical containers, and architectural applications. Buyers shortlisting suppliers should verify that mill test certificates (MTCs) issued under EN 10204 Type 3.1 confirm these compositional limits heat-by-heat — not just at the product family level.

The table below maps the four equivalent designations for this alloy across major trade standards, which is critical when writing purchase orders that must satisfy multiple regulatory jurisdictions simultaneously:

Designation System	Grade Code	Primary Standard
American (UNS)	UNS S30400	ASTM A240
European (EN)	EN 1.4301	EN 10088-2
Japanese (JIS)	JIS SUS304	JIS G4305
Chinese (GB)	06Cr19Ni10	GB/T 3280

Mechanical performance requirements under ASTM A240 for the cold-rolled and annealed condition set minimum tensile strength at ≥515 MPa, yield strength at ≥205 MPa, and elongation at ≥40% — the high elongation figure being particularly relevant for buyers who will further process coils through deep drawing or roll-forming operations. Hardness is capped at ≤201 HBW / ≤92 HRB, confirming the fully annealed state.

Thickness range: 0.3–6.0 mm (keyword focus: 0.3–3.0 mm cold-rolled strip)
Width range: 1,000–2,000 mm
Surface finishes available: 2B, BA, No.4, HL, Mirror 8K
Corrosion standard reference: NACE MR0175 for sour-service chemical environments
Inspection options: SGS or Bureau Veritas (BV) pre-shipment inspection recommended for first-order verification

One practical trade-off buyers should factor in: the 2B finish is the default cold-rolled surface and suits most industrial applications, but mirror 8K finishing adds lead time and commands a price premium — confirmed by the platform variant spread of USD 1,200–2,440 per ton across Kuaima Steel Co., Ltd.'s listed coil products. Buyers should specify finish code explicitly in the purchase order to avoid substitution. Request heat-specific MTC documentation and confirm third-party inspection scope with SGS or Bureau Veritas before finalizing order terms.

Pricing, MOQ and Order Economics

304 stainless steel coil in cold-rolled, annealed condition sourced from verified Chinese manufacturers carries a price range of USD 1,200–2,440 per metric ton across the variant spectrum listed on the platform, with standard 2B-finish coils in the 0.3–3.0 mm thickness band typically clearing between USD 1,420–1,700/ton FOB Qingdao depending on surface finish, width, and order volume. Mirror 8K and BA finishes command a premium toward the upper end of that range, reflecting additional cold-rolling passes and surface treatment costs that buyers should budget for separately from base material.

MOQ — platform listing: 1 metric ton (sample or trial order threshold as listed per variant)
MOQ — commercial shipment: 20 tons, equivalent to one 20FT container; this is the practical floor for FOB Qingdao or CIF destination port orders where per-unit freight economics make sense
Price drivers by finish:

- 2B (standard cold-rolled, annealed): USD 1,420–1,600/ton

- BA (bright annealed): USD 1,600–1,800/ton (indicative)

- Mirror 8K: USD 1,800–2,440/ton depending on thickness and width

Payment terms: 100% irrevocable L/C at sight, drawable through Bank of China, ICBC, or CCB — standard for first-order risk mitigation on coil volumes above 20 tons
Incoterms available: FOB Qingdao, CIF destination port
Third-party inspection: SGS or Bureau Veritas (BV) pre-shipment inspection is strongly recommended; MTCs issued per EN 10204 3.1 should accompany every shipment as a baseline document requirement
2026 tariff consideration: Buyers routing material into the EU should account for the CBAM phased rollout, which adds a carbon cost layer to stainless imports and may affect landed price calculations; US Section 232 tariff exposure remains an active variable for North American buyers evaluating total cost of ownership

Kuaima Steel Co., Ltd., carrying a USD 3,000,000 platform security deposit and Diamond Member status since 2020, represents the category of audited supplier where L/C payment terms and third-party inspection through SGS or BV can be negotiated into the purchase contract from the first order — buyers should request an itemised quote specifying finish grade, width tolerance, and EN 10204 3.1 MTC inclusion before committing to any volume above the 20-ton container threshold.

Trade-offs and Verification Checklist

Sourcing 304 stainless steel coil to ASTM A240 from a platform-audited Chinese manufacturer involves concrete advantages and equally concrete trade-offs that every shortlisting buyer should map before issuing a purchase order. Kuaima Steel Co., Ltd. carries a USD 3,000,000 platform security deposit and has held Diamond Member status since 2020 — both verifiable signals of financial commitment to the platform. However, buyers should understand what that deposit does and does not guarantee: it demonstrates platform accountability, but it also reflects a fixed capital commitment that can reduce a supplier's room to negotiate on unit pricing, particularly on smaller runs near the 20-ton MOQ threshold. Buyers seeking aggressive spot-price flexibility on sub-container volumes may find that a supplier operating at this deposit level holds its listed price range of USD 1,200–2,440/ton more firmly than a lighter-capitalized vendor would.

A second trade-off worth stating plainly: Kuaima Steel's documented production strength centres on seamless pipe lines — Seamless steel pipe, Boiler steel pipes, Oil well pipe, and related tubular categories account for the majority of its listed manufacturing output. Buyers procuring 304 SS coil as a primary line item, rather than alongside pipe orders, should request dedicated coil-mill documentation during pre-order due diligence to confirm that cold-rolling and annealing capacity is not subcontracted. The practical mitigation is straightforward: commission a pre-shipment inspection through SGS or Bureau Veritas (BV) that specifically covers mill test certificates (MTC) issued under EN 10204 3.1, confirming the chemical composition — Cr 18.0–20.0%, Ni 8.0–10.5%, C ≤0.08% — matches the ASTM A240 heat certificate before the bill of lading is issued.

Use the checklist below before finalising any purchase order:

1. Grade cross-reference: Confirm 304 / EN 1.4301 / UNS S30400 / JIS SUS304 equivalence appears on the MTC — all four designations should be present for multi-market resale.

2. Standard compliance scope: Verify the shipment covers ASTM A240, EN 10088-2, and JIS G4305 simultaneously if your end-market requires dual certification.

3. Third-party inspection: Instruct SGS or Intertek to witness hardness testing (≤201 HBW / ≤92 HRB) and tensile verification (≥515 MPa) at the mill, not at the port.

4. CBAM readiness: EU-bound shipments in 2026 fall under the EU Carbon Border Adjustment Mechanism phased rollout — request embedded carbon data in the commercial invoice package before booking with COSCO Shipping or any nominated carrier out of Qingdao or Rizhao.

5. Surface finish confirmation: Specify 2B, BA, No.4, HL, or Mirror 8K in writing on the purchase order; surface finish disputes are the most common post-shipment quality claim on SS coil.

6. Payment instrument: Use a 100% irrevocable L/C at sight through Bank of China, ICBC, or CCB to align with the supplier's standard commercial terms and reduce settlement risk on both sides.

Request the full document set — MTC, COO, CIQ Certificate, Packing List, and Commercial Invoice — before the vessel departs Qingdao or Rizhao, and cross-check the MTC chemical values against the ASTM A240 published limits independently; this single step eliminates the majority of post-arrival disputes on stainless coil shipments.

Featured Supplier

Kuaima Steel Co., Ltd. is a verified factory-type manufacturer based in Shandong Province, China, holding Diamond Member status on the platform since 2020 and maintaining a USD 3,000,000 platform security deposit — both independently audited credentials.

Founded in 2007; operates as a verified custom manufacturer
Platform-audited supplier with Diamond Member status since 2020
Platform security deposit: USD 3,000,000
Product categories span 12 lines, including Seamless steel pipe, Boiler steel pipes, and Oil well pipe
Relevant to this guide: cold rolled stainless steel coil production aligns with the factory's multi-line steel processing capability across thickness ranges such as 0.3–3.0mm in ASTM A240-compliant grades including 304
Primary markets served include Asia and Africa; international track record outside these regions is still developing

Buyers sourcing 304 stainless steel coil in cold rolled, annealed condition should note that Kuaima Steel's core focus remains pipe products, which may affect breadth of coil-specific inventory and pricing flexibility.

To review Kuaima Steel Co., Ltd.'s verified profile, audited credentials, and current product listings, visit:

Frequently Asked Questions

What are the key specifications of 304 stainless steel coil under ASTM A240?

ASTM A240 304 stainless steel coil is defined by a chromium content of 18.0–20.0% and nickel of 8.0–10.5%, with a maximum carbon content of 0.08%. Cold-rolled and annealed product in the 0.3–3.0 mm thickness range must meet a minimum tensile strength of 515 MPa and yield strength of 205 MPa. The annealing process relieves work-hardening stress, restoring ductility and producing the smooth, uniform surface finish demanded in food-processing, architectural, and chemical-equipment applications.

What is the difference between cold-rolled annealed 304 coil and hot-rolled 304 coil?

Cold-rolled annealed 304 coil offers tighter dimensional tolerances—typically ±0.02 mm on thickness versus ±0.1 mm for hot-rolled—and a smoother 2B or BA surface finish. Hot-rolled coil, usually produced above 3.0 mm, carries mill scale and requires pickling before further processing. For precision-stamped components or decorative panels where surface quality is critical, cold-rolled annealed material is the standard choice. The trade-off is cost: cold-rolled processing adds rolling and annealing steps, raising the per-tonne price by a measurable margin.

How does 304 stainless steel coil compare to 316L for corrosion-sensitive applications?

304 (UNS S30400) provides excellent general corrosion resistance in atmospheric and mildly acidic environments, but lacks the 2.0–3.0% molybdenum addition found in 316L (UNS S31603). That molybdenum content gives 316L substantially better resistance to chloride pitting and crevice corrosion—critical in marine or pharmaceutical environments. For buyers, the practical implication is straightforward: where chloride exposure is moderate to high, specifying 316L under ASTM A240 is the safer engineering decision, despite the 20–35% price premium over 304 coil at equivalent gauge.

What thickness tolerances and surface finishes should buyers specify when ordering 304 cold-rolled coil?

Under ASTM A240 and the companion dimensional standard ASTM A480, buyers should specify: thickness tolerance class (standard or precision), nominal width, and one of the following mill finishes:

2B: bright, cold-rolled, annealed and skin-passed — the most common commercial finish
2D: dull, cold-rolled and annealed — preferred for deep drawing
BA (bright annealed): mirror-like, requiring controlled-atmosphere annealing

For coil in the 0.3–1.0 mm range, specifying a precision thickness tolerance (±0.015 mm) is advisable to avoid downstream stamping rejects. Always confirm edge condition—mill edge versus slit edge—in the purchase order.

What payment terms and trade documents are standard when importing 304 stainless coil from China?

Most Chinese mill and trading transactions for 304 coil use one of three payment structures: 30% T/T deposit with 70% against copy of Bill of Lading; irrevocable Letter of Credit (L/C) at sight issued by a rated bank; or D/P (Documents against Payment) for established buyer-supplier relationships. Required shipping documents typically include a commercial invoice, packing list, Bill of Lading, Mill Test Certificate (MTC) referencing ASTM A240 heat and lot numbers, and a Certificate of Origin. Buyers sourcing under L/C should confirm that the MTC is issued by the mill, not a third-party agent, to avoid certificate discrepancies at customs.

How should buyers evaluate a Chinese stainless steel supplier's platform security deposit and Diamond Member status?

A platform security deposit—such as the USD 3,000,000 deposit maintained by Kuaima Steel Co., Ltd.—functions as a financial performance bond held by the trading platform. It signals that the supplier has passed financial vetting and accepts liability exposure if contractual obligations are not met. Diamond Member tenure from 2020 indicates sustained platform compliance over multiple audit cycles, not merely a one-time registration. Buyers should treat these signals as a starting filter, not a final check: independent third-party inspection (SGS, Bureau Veritas, or equivalent) of each shipment remains essential regardless of platform credentials.

What are the main sourcing risks buyers should plan for when purchasing 304 stainless coil in 2026?

Three challenges are shaping 304 coil procurement in 2026:

1. \\Nickel price volatility\\ — nickel is the primary cost driver in 304 chemistry; spot price swings of 15–25% within a quarter are not unusual, making fixed-price long-term contracts difficult to sustain.

2. \\Carbon border adjustments\\ — expanding CBAM-style regulations in the EU and proposed measures in other markets are adding compliance documentation requirements to stainless imports.

3. \\Mill lead-time variability\\ — post-2024 capacity rationalizations at several Chinese mills have tightened cold-rolling schedules, extending standard lead times from 15–20 days to 25–35 days for non-stocked gauges.

Building buffer stock or securing rolling slots in advance mitigates the third risk directly.

What should a buyer verify in a Mill Test Certificate for ASTM A240 304 stainless coil?

A compliant MTC for ASTM A240 Grade 304 must include: heat number, lot/coil number, chemical composition (confirming Cr 18–20%, Ni 8–10.5%, C ≤ 0.08%), mechanical test results (tensile, yield, elongation), and the certifying statement that material meets ASTM A240/A240M. Kuaima Steel, as a platform-audited verified manufacturer, is expected to supply mill-origin MTCs traceable to the producing heat—buyers should cross-check the heat number on the MTC against the coil tag on arrival. Any MTC that omits heat traceability or lists only a trading company as the issuer warrants rejection or independent re-testing.

Conclusion

Sourcing 304 cold-rolled annealed coil to ASTM A240 in 2026 demands more than a price check. Buyers who lock in specifications early — thickness tolerance, surface finish, and mill test certificate requirements — avoid the costly rework that loose procurement leaves open. With 0.3–3.0 mm gauges covering everything from food-processing fabrication to architectural cladding, the range is broad, but grade discipline and documentary compliance remain the real differentiators between a smooth shipment and a customs delay.

Two realities deserve attention: Section 232 tariff exposure continues to reshape landed costs for North American buyers, and lead times from Chinese mills tighten seasonally. Building those variables into your RFQ timeline is not optional — it is risk management.

Kuaima Steel Co., Ltd. — a platform-audited Diamond Member since 2020 carrying a USD 3,000,000 security deposit — is listed on Sinoali. Visit the Kuaima Steel supplier page on Sinoali to request a 2026 mill price sheet and certified documentation package for ASTM A240 304 coil.

Sources and References

Written by Sinoali Editorial Desk — Sinoali Steel Research Team

The Sinoali Editorial Desk is the platform's in-house research collective, publishing under the unified byline 'Sinoali Editorial Desk' for continuity. Each article is reviewed by a named domain expert (see 'Reviewed by' below). Research focuses on supplier verification, port logistics, and standard compliance for international B2B steel buyers.

Reviewed by Dr. Chen Yifan — Materials Compliance Reviewer. Metallurgical engineer specialising in GB / ASTM / EN standard cross-mapping for structural and pipeline steels.

Published 2026-04-15 · Sinoali Editorial Desk

常见问题

What are the key specifications of 304 stainless steel coil under ASTM A240?

What is the difference between cold-rolled annealed 304 coil and hot-rolled 304 coil?

How does 304 stainless steel coil compare to 316L for corrosion-sensitive applications?

What thickness tolerances and surface finishes should buyers specify when ordering 304 cold-rolled coil?

Under ASTM A240 and the companion dimensional standard ASTM A480, buyers should specify: thickness tolerance class (standard or precision), nominal width, and one of the following mill finishes: - 2B: bright, cold-rolled, annealed and skin-passed — the most common commercial finish - 2D: dull, cold-rolled and annealed — preferred for deep drawing - BA (bright annealed): mirror-like, requiring controlled-atmosphere annealing For coil in the 0.3–1.0 mm range, specifying a precision thickness tolerance (±0.015 mm) is advisable to avoid downstream stamping rejects. Always confirm edge condition—mill edge versus slit edge—in the purchase order.

What payment terms and trade documents are standard when importing 304 stainless coil from China?

How should buyers evaluate a Chinese stainless steel supplier\'s platform security deposit and Diamond Member status?

What are the main sourcing risks buyers should plan for when purchasing 304 stainless coil in 2026?

Three challenges are shaping 304 coil procurement in 2026: 1. **Nickel price volatility** — nickel is the primary cost driver in 304 chemistry; spot price swings of 15–25% within a quarter are not unusual, making fixed-price long-term contracts difficult to sustain. 2. **Carbon border adjustments** — expanding CBAM-style regulations in the EU and proposed measures in other markets are adding compliance documentation requirements to stainless imports. 3. **Mill lead-time variability** — post-2024 capacity rationalizations at several Chinese mills have tightened cold-rolling schedules, extending standard lead times from 15–20 days to 25–35 days for non-stocked gauges. Building buffer stock or securing rolling slots in advance mitigates the third risk directly.

Kuaima Steel 304 SS Coil Cold Rolled ASTM A240 2026 Guide

Kuaima Steel 304 SS Coil Cold Rolled ASTM A240 2026 Guide

Market Overview

Key Industry Trends (2026–2030)

What is driving demand for cold-rolled 304 stainless steel coil?

How are supply dynamics shaping the cold-rolled 304 coil market?

Which process standards and verification steps matter most for 304 coil procurement?

Material Grades and Technical Specifications

Pricing, MOQ and Order Economics

Trade-offs and Verification Checklist

Featured Supplier

Frequently Asked Questions

What are the key specifications of 304 stainless steel coil under ASTM A240?

What is the difference between cold-rolled annealed 304 coil and hot-rolled 304 coil?

How does 304 stainless steel coil compare to 316L for corrosion-sensitive applications?

What thickness tolerances and surface finishes should buyers specify when ordering 304 cold-rolled coil?

What payment terms and trade documents are standard when importing 304 stainless coil from China?

How should buyers evaluate a Chinese stainless steel supplier's platform security deposit and Diamond Member status?

What are the main sourcing risks buyers should plan for when purchasing 304 stainless coil in 2026?

What should a buyer verify in a Mill Test Certificate for ASTM A240 304 stainless coil?

Conclusion

Sources and References

Related Reading

常见问题

What are the key specifications of 304 stainless steel coil under ASTM A240?

What is the difference between cold-rolled annealed 304 coil and hot-rolled 304 coil?

How does 304 stainless steel coil compare to 316L for corrosion-sensitive applications?

What thickness tolerances and surface finishes should buyers specify when ordering 304 cold-rolled coil?

What payment terms and trade documents are standard when importing 304 stainless coil from China?

How should buyers evaluate a Chinese stainless steel supplier\'s platform security deposit and Diamond Member status?

What are the main sourcing risks buyers should plan for when purchasing 304 stainless coil in 2026?

What should a buyer verify in a Mill Test Certificate for ASTM A240 304 stainless coil?