Purchasing, quality and logistics

Plate UT: internal defects, scan coverage and acceptance

Plate UT: internal defects, scan coverage and acceptance: a practical guide to specifications, price comparison and quality checks for steel buyers.

Zharfahan Editorial5 min read
Zharfahan editorial illustration: Ultrasonic waves reveal a planar discontinuity inside a thick steel plate.

What this guide decides

Specify the standard, acceptance class, scan area, probe and reporting for the application and thickness; UT OK is insufficient.

Executive summary

  • Main decision: Specify the standard, acceptance class, scan area, probe and reporting for the application and thickness; UT OK is insufficient.
  • Comparison basis: Specify standard and class, thickness and test area, coverage or grid, equipment and probe, calibration block, acceptance criteria, map and operator qualification.
  • First risk: Report without acceptance class

What decision are you making?

UT transmits sound through plate thickness and examines reflections from boundaries and defects, helping identify laminations and internal discontinuities. Evaluate technical specifications, the price basis, delivery terms and quality evidence together. A lower number is not a comparable offer if it covers a different grade, weight, coating or delivery scope.[1][2]

When importing steel from Iran, price differences often reflect weight basis, local tax treatment, delivery location, cutting, packing, freight, quote validity and documentation. Keep one order, lot and acceptance reference from RFQ through discharge and any claim. Specify settlement currency, the named port or final delivery place, inspection language and destination project requirements. Ask the responsible parties to confirm applicable border charges and documents for the actual shipment rather than assuming that an Iranian domestic quote represents the importer's landed cost.

Technical mechanism and price impact

Frequency, probe, coupling, surface, thickness and defect orientation affect sensitivity. Full-area mapping and edge scanning may have different criteria.[2][3][4]

Specify standard and class, thickness and test area, coverage or grid, equipment and probe, calibration block, acceptance criteria, map and operator qualification. Compare offers only after aligning units, the weight basis, taxes, packaging, loading, freight and quote validity. An omitted cost can outweigh the apparent saving per kilogram. Keep the supplier’s currency and payment date visible before converting to your purchasing currency.

Request comparable quotations

Ask every supplier to answer the same written specification. This prevents an apparently cheaper offer from silently changing the product or scope. Confirm the following before comparing prices:

  • Procedure and class
  • Calibration
  • Coverage and edges
  • Indication map
  • Traceability to the plate

Compare the options

Use this table to structure the decision. It does not replace engineering calculations or the contract. The final column identifies the evidence to review before accepting an offer.

Grid scanningThe class and application permit itLine spacing
Full scanningRequired by risk or standardActual coverage
UT after cuttingCritical parts or orientation require itID transfer

Common risks and warning signs

Errors often begin when a trade name replaces a technical specification, one photograph stands for an entire shipment, or the delivery scope is missing from the quote. Address these specific risks: Report without acceptance class; Insufficient coverage; Unsuitable surface; Losing the defect map after cutting. Turn each risk into a written acceptance criterion, sampling requirement or traceable document.

A standard number alone does not demonstrate conformity. Specify the edition, grade, dimensions, tolerances, test method, heat or batch number and acceptance authority. For an import project, confirm the destination’s requirements and the project’s approved specification; an Iranian market designation is not automatic evidence of an equivalent local grade.

Make the purchasing decision

A statement that plate was UT tested is incomplete. Obtain the method, coverage and indication map with the material.[4][5]

Before ordering, prepare a single comparison sheet covering the product, quantity, unit, theoretical and actual weight, base price, taxes, freight, delivery window, documents and acceptance criteria. Identify who pays each cost and who records discrepancies at receipt. This makes the negotiation clearer and gives the receiving team an agreed basis for checking the shipment.

Checklist before you order

  1. 1Procedure and class
  2. 2Calibration
  3. 3Coverage and edges
  4. 4Indication map
  5. 5Traceability to the plate
  6. 6Record the price basis, unit, taxes, loading and freight in the quotation
  7. 7Match shipment markings and documents to the delivered goods before unloading

Frequently asked questions

What should I check first when evaluating ultrasonic testing of steel plate?

Align the product definition and acceptance criteria before comparing prices. Specify standard and class, thickness and test area, coverage or grid, equipment and probe, calibration block, acceptance criteria, map and operator qualification.

Is price alone enough to decide on ultrasonic testing of steel plate?

No. Prices are comparable only when grade, dimensions, weight, quality, documents, delivery scope and validity match. A statement that plate was UT tested is incomplete. Obtain the method, coverage and indication map with the material.

Sources and how they were used

Standards and primary sources define the method, terminology and scope of each decision. The project’s contractual edition and the approved national standard always take precedence.

  1. [1]Iranian national standards and servicesIran National Standards Organization
  2. [2]ISO/TC 17 — SteelInternational Organization for Standardization
  3. [3]Steel StandardsASTM International
  4. [4]Iran Mercantile Exchange physical-market trading statisticsIran Mercantile Exchange
  5. [5]Steel & Metals Price Assessment MethodologyS&P Global Energy — Platts

Where to go next

Related guides to support your next buying decision.

Zharfahan editorial illustration: Two plates pass through general-load and pressure-vessel toughness qualification fixtures.Flat steel

Decision guide · 5 min

A283 vs A516 plate: general fabrication and pressure-vessel requirements

A283 covers a family of general carbon-steel plates, while A516 is associated with pressure-vessel applications and different requirements. Grade number, thickness and delivery condition complete the property specification. Select general-purpose or pressure-vessel plate against the design code, temperature, thickness, toughness and complete certification; market-name substitution is unsafe.

Read the guide