Direct answer: ASTM B443 covers rolled UNS N06625 plate, sheet and strip. It does not create one universal tolerance for every Alloy 625 order. The applicable thickness, width, length, straightness and flatness limits depend on product form, ordered dimensions, edge condition and the edition referenced by the purchase order.
Plate, Sheet and Strip Are Different Order Forms
| Form | Typical supply direction | Critical dimensional checks |
|---|---|---|
| Plate | Hot rolled or solution annealed plate, cut size or mill size | Thickness, width, length, flatness, edge and machining allowance |
| Sheet | Thinner flat product, commonly cold rolled | Thickness variation, width/length, surface and flatness |
| Strip | Narrow or coiled product | Thickness, width, camber, coil ID and edge condition |
How to Specify Size Correctly
State thickness × width × length in one unit system and identify whether dimensions are nominal, minimum or finished. For machined components, add machining allowance instead of assuming the mill tolerance will leave sufficient stock. If multiple cut blanks are required, list the quantity for every size.
Which Tolerances Matter?
- Thickness: verify the permitted variation for the ordered form and size range.
- Width and length: state mill edge, sheared, saw-cut, waterjet-cut or machined edge.
- Flatness: define the measurement method and any tighter project limit.
- Surface: specify mill, pickled, ground or polished finish and acceptable defect removal.
- Squareness and edge quality: important for laser-cut or machined blanks.
Standard Tolerance vs Special Tolerance
“ASTM standard tolerance” is acceptable only when the current ordered edition clearly covers the product. If fabrication needs a tighter result, put the numeric requirement and inspection method on the drawing or purchase order. Tighter tolerances may require grinding, leveling or machining and will affect price and lead time.
Inspection Documents
Request an EN 10204 3.1 MTC showing heat number, UNS N06625, ordered ASTM edition, heat-treatment condition, chemistry and mechanical results. Add a dimensional report, surface inspection, PMI and ultrasonic testing when the project requires them.
FAQ
What is the maximum ASTM B443 plate size?
The specification scope does not guarantee one commercial maximum. Mill capability, ingot route, rolling width, thickness and transportation limits determine availability.
Is 2.4856 the same purchasing designation as UNS N06625?
It identifies the closely corresponding European material, but the purchase order must still name the required product standard and edition.
Can plate be supplied to a finished tolerance?
Yes, through secondary cutting, leveling, grinding or machining when the required values and inspection method are agreed.
Primary References
Engineering note: Values and acceptance criteria must be checked against the edition of the governing standard named in the purchase order. Application-specific design approval remains the responsibility of the purchaser or project engineer.
Post time: Sep-11-2026