Stainless steel delivery requires special care due to its high value and the risk of grade substitution: verify the grade through testing, control weight using the correct density, and inspect the surface for scratches. Let’s review the checklist.
You are receiving a load of ۳۰۴ stainless steel sheets, and they look fine. However, there are two hidden risks: the actual grade may be ۲۰۱ rather than ۳۰۴, and the surface may have scratches that make it unsuitable for the customer’s exposed application. Neither issue can be identified by counting the number of sheets, so they must be checked separately.
Why the Stainless Steel Checklist Must Be More Rigorous
Stainless steel involves two additional risks compared with ordinary steel: substitution with a lower grade (due to the high value of nickel), and surface damage, which is important for exposed applications. The three inspection areas are grade verification, weight control using the correct density, and surface finish condition.
Grade verification and surface condition are exactly what counting the number of sheets can never reveal.
Step-by-Step Checklist
- Before unloading: Check the invoice against the grade, form, thickness, finish, and declared weight.
- Grade verification: Use a magnet test as an initial indication; if in doubt, conduct an acid test or request a certificate of analysis.
- Weight control: Calculate the theoretical weight using the correct density (۸.۰) and compare it with the weighbridge reading.
- Finish inspection: Check the surface for lines, scratches, stains, and finish uniformity, especially for exposed applications.
- Edge and dimension inspection: Check the dimensions and the straightness of the edges.
- In case of discrepancy: Take photos before settlement and contact the seller.
Signs of a Problematic Load
| Sign | What it indicates | Action |
|---|---|---|
| Noticeable attraction to a magnet | Possible grade ۲۰۱ or ۴۳۰ instead of ۳۰۴ | Conduct an acid test or analysis and request the certificate |
| Unusually low price | A red flag for grade substitution | Verify the grade before settlement |
| Surface lines and scratches | Transportation damage or low quality | Reject it for exposed applications or request a discount |
| Weight lower than theoretical | Underweight or lower thickness | Check the thickness using the correct density |
This inspection is the most essential step before settlement for a product that is both high-value and at risk of grade substitution.
An Additional Point: Documenting Everything on the Spot
Taking photos of the roll mark or the mill label on each sheet package before opening the protective film provides evidence that can be useful if a dispute arises later. This takes only a few extra seconds, but it is highly valuable when negotiating with the seller over a discrepancy.
Frequently Asked Questions
مهم‌ترین چک هنگام تحویل استیل چیست؟
تأیید گرید؛ با تست آهنربا به‌عنوان نشانهٔ اولیه و در صورت شک، تست اسید یا درخواست گواهی آنالیز، تا مطمئن شوید گرید تحویلی همان چیزی است که خریده‌اید.
چرا بررسی خط و خش سطح در استیل مهم است؟
چون استیل اغلب برای مصارف نمایان استفاده می‌شود و خط و خش، ورق را برای کاربرد تزئینی بی‌ارزش می‌کند، حتی اگر گرید و ضخامت درست باشد.
کنترل وزن استیل چه تفاوتی با فولاد دارد؟
باید از چگالی درست (حدود ۸.۰ به‌جای ۷.۸۵) استفاده کنید و چون قیمت هر کیلو بالاست، دقت وزن اهمیت بیشتری دارد.
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