| 1 | ASTM A722 Grade 150 Production | ASTM A722
Uncoated high-strength steel bars for prestressing concrete | Minimum tensile strength: 150 ksi, approximately 1,035 MPa. The required mechanical properties must be confirmed for the ordered bar size. | Material test certificate, heat number, tensile-test results, chemical analysis, and dimensional inspection report | Confirm whether the supplied bar is certified to the requested ASTM A722 edition and whether the certificate covers every production lot. |
| 2 | ASTM A722 Grade 160 Production | ASTM A722
High-strength prestressing steel bar classification | Minimum tensile strength: 160 ksi, approximately 1,100 MPa. Mechanical requirements may vary by size and applicable specification edition. | Heat-specific mill certificate, tensile and elongation results, inspection traceability, and certificate of conformity | Grade 160 should not be substituted for Grade 150 without design approval, because anchorage and structural calculations may be grade-specific. |
| 3 | Continuous Thread Bar Capability | Project thread drawing, purchaser specification, and compatible anchorage system | Threads may run continuously along the bar or be supplied in defined threaded zones. Thread pitch, major diameter, flank geometry, and tolerance are order-specific. | Approved thread drawing, thread-gauge records, pitch measurement, major/minor diameter records, and sample inspection data | ASTM A722 defines the steel-bar material requirements; it does not by itself select the thread profile or guarantee compatibility with a particular nut or coupler. |
| 4 | Diameter and Length Range | ASTM A722 size requirements plus project drawings and transport limits | Common project sizes include approximately 12.7–63.5 mm, but the accepted range depends on the applicable standard, manufacturer’s process, and project specification. | Dimensional inspection report, straightness record, cut-length tolerance, and packing list with piece counts | Confirm actual rolling, threading, cutting, and straightening capacity rather than relying only on a catalogue range. |
| 5 | Steel Chemistry and Heat Traceability | Applicable ASTM material requirements and purchaser-approved chemistry limits | Low-alloy or alloy steel chemistry is controlled by the specified material standard. Carbon equivalent and weldability must be assessed separately when welding is proposed. | Heat analysis, product analysis where required, ladle number, heat-treatment record, and full traceability from billet to finished bar | Threaded prestressing bars are generally selected for mechanical performance; welding or field heating should not be assumed acceptable without engineering approval. |
| 6 | Surface Condition and Corrosion Protection | ASTM A722 for uncoated bars; separate coating or corrosion-protection specification when required | Uncoated bars should be free from harmful defects that could affect performance. Galvanizing, epoxy, paint, or other protection requires a separate compatibility review. | Surface inspection report, coating certificate if applicable, coating thickness record, and storage or corrosion-control procedure | Check whether coating changes thread dimensions, nut engagement, friction, anchorage performance, or installation torque. |
| 7 | Mechanical and Dimensional Quality Control | ASTM A722, approved inspection and test plan, and project acceptance criteria | Typical controls include tensile strength, elongation, bar diameter, thread pitch, thread diameter, straightness, length, and visual surface condition. | Inspection and test plan, calibrated equipment list, laboratory accreditation evidence, nonconformance procedure, and final inspection release | Specify sampling frequency and acceptance criteria before production; otherwise, different suppliers may apply non-comparable inspection practices. |
| 8 | Anchorage, Nut, and Coupler Compatibility | Approved structural design, thread drawing, and anchorage-system requirements | Nut and coupler performance depends on thread geometry, effective engagement length, material strength, hardness, bearing area, and installation procedure. | Assembly drawing, nut and coupler material certificates, fit-up samples, proof-load results, and installation instructions | Order the bar, nut, plate, and coupler as a verified system whenever possible; mixing components from different sources requires technical validation. |
| 9 | Export Packing and Logistics Readiness | Purchase contract, Incoterms, destination import rules, and project packing specification | Bars may be bundled by heat, diameter, length, or project mark. Thread protectors and moisture-resistant wrapping are commonly required for long-distance shipment. | Packing list, commercial invoice, certificate of origin, export documents, fumigation certificate where applicable, and shipping photographs | Confirm maximum bundle weight, container loading plan, corrosion protection during transit, and port or inland-delivery restrictions. |
| 10 | Third-Party Inspection and Technical Support | Project quality plan, purchaser inspection requirements, and destination regulatory rules | Independent inspection may cover raw-material traceability, mechanical testing, thread gauging, visual inspection, packing, and document review before shipment. | Third-party inspection report, calibration certificates, approved drawings, test-laboratory reports, and corrective-action records | For critical prestressed or ground-engineering applications, agree on hold points, witness points, document language, and response time before placing the purchase order. |
