Specify flatness, camber and squareness as separate acceptance requirements attached to the delivered product. State the governing document and edition, the feature being assessed, the measurement condition and span, the permitted deviation, and the evidence required from the supplier. Complete these details before releasing the order.
This guide develops the shape clause within a complete steel purchase specification . It does not supply a universal tolerance table. A mill certificate without the agreed shape evidence leaves that part of the order unresolved.
1. Identify what will arrive and when shape matters
Record grade, product form, dimensions, edge condition and delivery condition. Define the supplied form before choosing its assessment method. Decide whether the requirement concerns the supplied sheet, a sample taken from a coil, or a separately agreed condition after a named operation. Do not transfer a cut-sheet requirement to a coil without defining how it will be assessed.
Describe the downstream need in practical terms: feeding an edge, locating a blank or presenting a surface to a fixture. Ask the responsible engineer which characteristic controls that task. A more demanding limit on one characteristic cannot resolve an unspecified requirement on another. Keep processing expectations separate from the delivered-product acceptance; leveling and flattening have their own scope and limitations.
2. Establish the governing document and its scope
Identify the applicable product and dimensional documents, their agreed editions, the selected class or option and any additional purchase requirement. BSI’s EN 10051 overview illustrates product-specific scope. Read the actual applicable document before choosing a value; a public summary cannot establish a clause’s full conditions. See the source notes .
Reconcile the drawing, purchase order and supplier quotation. Give an agreed order of precedence where they differ. Avoid combining the smallest numbers from unrelated tables. If the supplier offers a named guarantee, obtain the applicable product coverage and document revision. SSAB’s flatness guarantee varies with product and strength; that example cannot approve another product’s capability. Keep the guarantee context with the enquiry record.
3. Build a requirement that another team can repeat
Use a separate line for each relevant characteristic. The following is an editorial working schedule; complete it with the applicable specification and competent supplier input.
| Field | What to agree | Release check |
|---|---|---|
| Delivered item | Grade, form, dimensions, edge and delivery condition | The quotation covers the same item |
| Characteristic | Flatness, camber or squareness; relevant face, edge or end | Each required feature has its own entry |
| Authority | Document, edition, clause/class and agreed exceptions | Conflicting documents are reconciled |
| Measurement basis | Reference, span, locations, support/restraint state and method | Supplier and receiver can assess the same condition |
| Acceptance | Limit, units and agreed decision rule | The limit stays attached to its measurement basis |
| Evidence | Sampling plan, result record, traceability and exception route | Responsibilities and required records are confirmed |
Scroll within the table to see all columns →
Replace “good flatness” with a defined requirement. Keep a numerical limit connected to its reference and span. Do not scale a span-based deviation to a different length by simple proportion unless the governing method explicitly permits it.
4. Turn the schedule into an agreed clause
A useful clause can follow this pattern: “For the identified delivered item, assess each listed characteristic under the cited document and edition, using the stated condition and measurement basis. Apply the listed limit and agreed decision rule, including the treatment of measurement uncertainty where relevant. Supply the agreed results linked to the material identity; refer exceptions to the named disposition process.”
This wording is a drafting framework, not a complete technical requirement. Attach the completed schedule; replace every open field with an agreed entry or a justified not-applicable decision. A reference to “standard quality” cannot fill an absent class, method or limit. Ask for written confirmation of every supplementary requirement, including any inspection the supplier does not normally provide.
5. Resolve mismatched quotations before purchase
Suppose a hypothetical quotation promises a flatness result while the buyer’s process needs an edge-camber condition. Request a response to the missing characteristic; the existing promise does not close that gap. In another hypothetical case, both parties state the same limit but assume different support conditions. Clarify the agreed condition and ask the supplier to confirm capability against it.
Record qualifications and proposed alternatives explicitly. If a supplier cannot meet the requested combination, the responsible buyer and engineer must decide whether to revise the requirement, change the supply route or decline the offer. Do not silently relax a limit to match a quotation. An unresolved answer remains open at order release.
6. Hand the agreed record to receiving
Send the final revision, material identifiers, evidence requirements and exception route to the receiving team. Agree who records results, who reviews borderline or incomplete evidence, and who can approve a disposition. Preserve the supplier’s qualifications alongside the accepted requirement. The delivery inspection guide covers the broader arrival workflow.
Any physical inspection needs a suitable safe procedure. This schedule provides no authority to release coil restraints, handle unsupported sheets or enter machinery. Keep inaccessible measurements and unresolved evidence visible. The completed order record identifies what will be verified later; it does not certify the delivered material in advance.