| Material Characteristics |
| Material | Carbon steel type | High carbon steel, generally containing approximately 0.60% to 1.00% carbon by mass, depending on the specified grade. | Higher carbon content provides increased hardness, strength, and wear resistance after suitable heat treatment. | Review the chemical composition report and confirm the applicable grade standard. |
| Common grades | Representative grades | SAE/AISI 1060: about 0.55%–0.65% C; SAE/AISI 1070: about 0.65%–0.75% C; SAE/AISI 1095: about 0.90%–1.03% C. Equivalent grades may differ by standard. | Grade selection should match the required hardness, forming capability, fatigue performance, and heat-treatment process. | Compare the mill certificate with the precise chemical limits in the purchase specification. |
| Typical applications | End-use suitability | Springs, saw blades, knives, scrapers, wear-resistant parts, agricultural components, and industrial cutting products. | High carbon steel is suitable where strength and wear resistance are more important than deep drawability or high weldability. | Request application references by product type, without relying only on a generic grade name. |
| Weldability | Process sensitivity | Generally limited compared with low-carbon steel because higher carbon content increases hardening and cracking risk in the heat-affected zone. | Welding may require qualified procedures, preheating, controlled cooling, and post-weld treatment. | Confirm welding restrictions and obtain a qualified welding procedure when welding is part of the application. |
| Mechanical and Dimensional Data |
| Mechanical properties | Tensile strength | Condition-dependent. Cold-rolled or hardened high-carbon strip commonly ranges from approximately 700 MPa to above 2,000 MPa. | Strength varies significantly with grade, reduction, annealing, quenching, tempering, and delivery condition. | Specify the delivery condition and test method; verify results against ISO 6892-1 or ASTM A370 where applicable. |
| Mechanical properties | Yield strength | Condition-dependent; annealed material may be substantially lower than cold-worked or hardened material. Use the contractual grade limit rather than a generic range. | Yield strength affects forming, spring-back, and load-bearing performance. | Require yield strength values on the inspection certificate when relevant to the design. |
| Mechanical properties | Elongation | Often approximately 2%–25%, depending on carbon level, thickness, cold reduction, and heat-treatment condition. | Lower elongation generally indicates reduced forming capability but may accompany higher strength and hardness. | Define the gauge length and test standard because reported elongation values are not directly comparable otherwise. |
| Hardness | Hardness range | Annealed material may be around 180–250 HBW; hardened and tempered products can commonly range from about 40 to 62 HRC, depending on grade and treatment. | Hardness is a key indicator for springs, blades, cutting edges, and wear parts. | Specify the hardness scale, test location, sampling frequency, and acceptance range. |
| Dimensions | Typical thickness capability | Approximately 0.15–6.00 mm for many cold-rolled coil supply programs; actual capability depends on the mill and product form. | Thickness capability influences material utilization, forming performance, and production yield. | Request a dimensional capability chart and confirm minimum order quantities for non-standard thicknesses. |
| Dimensions | Typical width capability | Approximately 20–1,500 mm for coil products, subject to equipment, edge condition, and thickness limitations. | Width availability affects slitting plans, scrap rate, container loading, and downstream productivity. | Confirm maximum coil width, slit-width tolerance, edge condition, and coil weight limits. |
| Dimensional tolerance | Thickness and width tolerance | Must be defined by the selected product standard or purchase specification; tolerances are not universal across grades and sizes. | Unspecified tolerances can create fit, forming, and yield problems during production. | Use the applicable dimensional standard and include target, tolerance, measurement method, and sampling plan in the purchase order. |
| Quality Standards and Surface Requirements |
| Product standard | High-carbon steel strip specification | ASTM A684/A684M is commonly used for high-carbon steel strip. EN 10132-4 covers cold-rolled narrow steel strip for quenching and tempering. | A recognized standard establishes requirements for chemistry, mechanical properties, dimensions, surface quality, and testing. | State the exact edition and grade designation in the request for quotation and purchase order. |
| Testing standard | Tensile testing | ISO 6892-1 or ASTM A370 may be used, provided the selected standard and test conditions are agreed in advance. | Consistent testing is essential for comparing suppliers and validating certificate data. | Check specimen direction, gauge length, test temperature, and laboratory identification. |
| Surface quality | Surface condition | Common requirements include a clean surface free from harmful cracks, seams, laps, rust scale, excessive pits, and damaging scratches. | Surface defects can reduce fatigue life, impair coating or plating, and cause rejection during slitting or stamping. | Define inspection lighting, defect limits, coil sampling length, and acceptable surface finish. |
| Edge quality | Mill edge or slit edge | Available as mill edge or slit edge, depending on the intended processing route and dimensional requirements. | Edge burrs, cracks, or camber may affect feeding, blanking, spring forming, and operator safety. | Specify edge type, maximum burr height, camber limit, and edge-crack acceptance criteria. |
| Flatness | Flatness and shape | Requirements should cover coil set, crossbow, waviness, and camber; numerical limits depend on the applicable standard and thickness. | Poor shape control can cause feeding errors, dimensional variation, and increased scrap in automated lines. | Request flatness measurements using an agreed method and sampling location. |
| Corrosion protection | Packaging and rust prevention | Common measures include dry wrapping, waterproof outer packaging, corrosion-inhibiting paper or film, and secure eye or circumference protection. | Proper protection reduces transit damage and corrosion during ocean freight or extended storage. | Approve a packaging specification covering humidity exposure, coil orientation, lifting points, and storage conditions. |
| Global Supplier Selection Criteria |
| Traceability | Heat and coil identification | Each coil should be traceable to a heat number, production date or batch, grade, dimensions, and inspection records. | Traceability supports claims handling, root-cause analysis, and controlled release into production. | Match coil tags, packing lists, mill certificates, and inspection reports before shipment. |
| Documentation | Inspection certificate | Certificate should normally include chemical analysis, mechanical test results, dimensions, delivery condition, standard, heat number, and coil weight. | Complete documentation reduces customs, receiving, and quality-assurance risks. | Require certificates before shipment or before final payment, as agreed contractually. |
| Quality system | Manufacturing controls | Prefer documented control of melting, rolling, annealing, heat treatment, slitting, calibration, nonconformance handling, and final inspection. | Process control is more reliable than evaluating quality only from a final sample. | Review current quality certificates, process flow, inspection plans, and corrective-action records. |
| Sampling | Pre-shipment inspection | Typical checks include chemistry review, thickness and width measurements, surface inspection, hardness or tensile testing, coil weight, and packaging condition. | Independent or buyer-appointed inspection can reduce the risk of receiving nonconforming material. | Define the sampling level, acceptance criteria, test laboratory, and inspection hold point. |
| Commercial fit | Minimum order and lead time | Minimum order quantities and lead times vary by grade, thickness, width, heat-treatment condition, and slitting requirements. | Commercial flexibility is important when validating a new grade or managing variable demand. | Request separate quotations for standard sizes, custom sizes, trial coils, and repeat-order quantities. |
| Logistics | Coil weight and loading | Coil weights should be matched to the buyer’s decoiler, crane, storage rack, container payload, and unloading equipment. | Incorrect coil weight can create handling hazards, equipment downtime, and additional transport cost. | Specify minimum and maximum coil weight, inner diameter, outer diameter, eye orientation, and securing method. |
| Payment risk | Commercial safeguards | Use staged documentation, clearly defined inspection rights, agreed nonconformance remedies, and shipment release conditions. | Contractual controls help protect quality, delivery, and payment interests in cross-border sourcing. | Include standards, tolerances, inspection procedures, claims periods, and remedy terms in the contract. |
| Note: The numerical ranges are indicative industry reference values. Final acceptance limits must be based on the selected grade, product standard, delivery condition, thickness, heat treatment, and mutually agreed purchase specification. |
