ASTM A480 is the general requirements standard many mills follow for stainless plate, sheet and strip. Use this method to find tolerances fast and write a PO that avoids disputes.
Five tolerance families you’ll use
- Thickness — cold‑rolled sheet is tighter than hot‑rolled plate.
- Width — affects blank utilization and edge trimming.
- Length — matters for cut‑to‑length blanks and plates.
- Flatness — usually for cold‑rolled sheet; plate flatness handled separately.
- Out‑of‑square/camber — critical for laser blanks and panels.
Method (repeatable)
- Identify form (sheet/plate/strip) and finish (2B/BA/No.4…)
- Find the thickness band then the width band
- Check flatness rules for your finish; note if “restricted flatness” is required
Worked example
Case: 304 2B sheet, 1.50 mm × 1219 × 2438. Go to the thickness table for cold‑rolled sheet at 1.50 mm, then the width band covering 1219 mm; then pick length/width tolerances for sheared blanks and the 2B flatness table. Record the set on your PO.
Tip: When tighter numbers are essential (e.g., laser blanks), ask for “restricted flatness” or a specific flatness per meter and confirm cost/lead time.
PO wording (copy/paste)
- Stainless sheet ASTM A240/480, 304 2B, 1.50 × 1219 × 2438 mm
- Tolerances per ASTM A480: thickness table (cold‑rolled sheet), width/length for sheared blanks
- Flatness ≤ X mm/m (restricted flatness if required)
- Edges: slit/mill/debur as stated
Baoli Engineering Team · Reviewed Oct 31, 2025