For structural designs of construction machinery, lifting equipment, mining trucks, high-cold plateau wind power and offshore engineering structures, quenched-and-tempered 690MPa ultra-high strength steel plates act as core structural materials to achieve equipment lightweighting, increase rated load capacity, reduce curb weight of complete machines and lower fuel consumption. Three major standard systems are widely applied globally: ASTM A514 (US standard), EN 10025-6 (European standard) and GB/T 16270 (Chinese standard), which form five mainstream grades: A514 Grade F, S690Q, S690QL, Q690D and Q690E.
Backed by GNEE Steel's over 18 years of export experience in high-strength steel plate supply, supported by mill original Mill Test Certificates (MTC) complying with ASTM, EN and Chinese national standards, physical test data from third-party organizations such as SGS, CE and marine survey bodies, as well as statistical data of batch ultrasonic testing pass rates, we carry out a systematic horizontal comparison of these five quenched-and-tempered 690MPa high-strength steel plates. We define the allowable range for equivalent replacement, material selection criteria and critical precautions for fabrication and welding, providing actionable reference for material specification, overseas quotation and inventory preparation for domestic and international engineering projects.
Do you require original manufacturer quality certificates for major steel grades, cut-to-size services, flaw detection, precision edge beveling, or stock availability plans for full plates? Connect directly with Gnee's technical engineers for personalized material selection advice, batch quality inspection reports, and the latest pricing.
What is A514 Grade F Plate?
A514 Gr.F is a classic quenched-and-tempered alloy high-strength steel with a specified minimum yield strength of 690MPa per ASTM standards. It is designed for welded structures of heavy construction machinery and bridges in North America, produced by quenching and tempering with a Cr-Ni-Cu-Mo-B alloy composition. The maximum production thickness is restricted to 65 mm.
What is S690Q Plate?
Manufactured to EN 10025-6. Grade code definition:
S = Structural Steel
690 = Minimum yield strength of 690 MPa
Q = Quenched and Tempered delivery condition
There is no mandatory low-temperature Charpy impact requirement; only Charpy impact property conformity at -20°C is required. It is the high cost-performance core grade for ambient-temperature service conditions in Europe, supplied in a full range of heavy wide and thick plate dimensions.
What is S690QL Plate?
S690QL is the low-temperature enhanced grade derived from S690Q. The suffix L denotes Low Temperature, with mandatory Charpy V-notch impact toughness qualification at -40°C. It is the key structural steel for Northern European low-temperature machinery, wind turbine towers and offshore platforms.
What is Q690D Plate?
A dominant moderate low-temperature grade complying with GB/T 16270-2013. Grade D is certified for Charpy impact testing at -20°C. It is applicable to heavy machinery, mining dump trucks and crane main girders operated in temperate zones of North, Central and Northwest China.
What is Q690E Plate?
Q690E is the top low-temperature grade of the Q690 series. Its Charpy impact performance at -40°C is equivalent to S690QL and A514 Gr.F. It is used for cold-region mining projects in Northeast China and Xinjiang, onshore wind turbine towers and nearshore construction mechanical structures.
Quick Overview Table of Key Specifications for the Five Major Grades
| Steel Grade | Executive Standard | Heat Treatment State | Characteristic Temperature for Charpy Impact | Main Application Region | Maximum Delivery Thickness |
|---|---|---|---|---|---|
| A514 Grade F | ASTM A514/A514M | Quenching + Tempering (Q+T) | -40℃ | North America, US & Canada Project | 65mm |
| S690Q | EN 10025-6 | Quenching + Tempering (Q+T) | -20℃ | EU conventional engineering machinery | 150mm |
| S690QL | EN 10025-6 | Quenching + Tempering (Q+T) | -40℃ | Northern Europe, Arctic, Offshore | 150mm |
| Q690D | GB/T 16270 | Quenching + Tempering (Q+T) | -20℃ | Domestic central & northern China conventional heavy industry | 150mm |
| Q690E | GB/T 16270 | Quenching + Tempering (Q+T) | -40℃ | Domestic alpine, wind power, offshore | 150mm |
A514 Grade F vs S690Q vs Q690D vs S690QL vs Q690E Plate: Chemical Composition
| Element | A514 Grade F | S690Q | S690QL | Q690D | Q690E |
|---|---|---|---|---|---|
| C | 0.10-0.20 | 0.20 | 0.20 | 0.20 | 0.20 |
| Si | 0.15 - 0.35 | 0.60 | 0.60 | 0.55 | 0.55 |
| Mn | 0.60 - 1.0 | 1.70 | 1.70 | 1.70 | 1.70 |
| P | 0.035 | 0.020 | 0.020 | 0.025 | 0.020 |
| S | 0.040 | 0.015 | 0.010 | 0.020 | 0.015 |
| Cr | 0.40 - 0.65 | ≤1.5 | ≤1.5 | ≤0.60 | ≤0.60 |
| Ni | 0.70 - 1.0 | ≤2.00 | ≤2.00 | ≤0.40 | ≤0.40 |
| Mo | 0.40 - 0.60 | ≤0.7 | ≤0.7 | ≤0.40 | ≤0.40 |
| B | 0.00050 - 0.0060 | Trace | Trace | Trace | Trace |
| Cu | 0.15 - 0.50 | ≤0.50 | ≤0.50 | ≤0.30 | ≤0.30 |
A514 Grade F vs S690Q vs Q690D vs S690QL vs Q690E Plate: Mechanical Property
| Performance Index | A514 Grade F | S690Q | S690QL | Q690D | Q690E |
|---|---|---|---|---|---|
| Yield Strength Rp0.2 (MPa) | ≥690 | ≥690 | ≥690 | ≥690 | ≥690 |
| Tensile Strength Rm (MPa) | 760~895 | 770~940 | 770~940 | 770~930 | 770~930 |
| Elongation A (%) | ≥18 | ≥14 | ≥14 | ≥14 | ≥14 |
| Charpy V-notch Impact Test Temperature | -40℃ | -20℃ | -40℃ | -20℃ | -40℃ |
| Minimum Impact Energy (J, Longitudinal) | ≥34 | ≥30 | ≥30 | ≥47 | ≥47 |
A514 Grade F vs S690Q vs Q690D vs S690QL vs Q690E Plate: Heat Treatment
| Item | A514 Grade F | S690Q | S690QL | Q690D | Q690E |
|---|---|---|---|---|---|
| Production Process | Integral quenching + high temperature tempering | Modulated quenching+tempering | Modulated quenching+tempering | Modulated quenching+tempering | Modulated quenching+tempering |
| Quenching Temperature | ≥900℃, water/oil quenching | 880~920℃ water quenching | 880~920℃ water quenching | 870~910℃ quenching | 870~910℃ quenching |
| Tempering Temperature | ≥620℃ | 600~660℃ | 600~660℃ | 600~650℃ | 600~650℃ |
| Post-heat treatment limit | Avoid a second high-temperature tempering to prevent a reduction in strength. | Avoid repeated tempering | Strictly prohibit hot forming | Cold forming only recommended | Cold forming only recommended |
A514 Grade F vs S690Q vs Q690D vs S690QL vs Q690E Plate: Weldability
| Welding Characteristic | A514 Grade F | S690Q | S690QL | Q690D | Q690E |
|---|---|---|---|---|---|
| Carbon Equivalent CEq | 0.58~0.65 | 0.52~0.60 | 0.52~0.60 | 0.50~0.58 | 0.50~0.58 |
| Preheating Temperature for Welding | 150~180℃ | 100~150℃ | 120~160℃ | 100~140℃ | 120~160℃ |
| Recommended Welding Consumable | Low hydrogen E9018 | Low hydrogen E8518 | Low hydrogen E8518 | J857Cr low hydrogen | J857Cr low hydrogen |
| Post-weld heat treatment(PWHT) | Required for thickness＞40mm | Optional for thick plate | Required for thickness＞35mm | Optional for thickness＞40mm | Required for thickness＞35mm |
| Cold Crack Sensitivity | High | Medium | Medium-High | Medium | Medium-High |
A514 Gr.F, S690Q, S690QL, Q690D, Q690E Quenched and Tempered High Strength Steel Plate Specification
| Item | Specification |
|---|---|
| Product | Quenched and Tempered High Strength Steel Plate |
| Available Grades | ASTM A514 Grade F, S690Q, S690QL, Q690D, Q690E |
| Standards | ASTM A514/A514M, EN 10025-6, GB/T 16270 |
| Thickness | 6–200 mm (Customized available) |
| Width | 1500–4000 mm |
| Length | 3000–18000 mm |
| Delivery Condition | Quenched and Tempered (Q+T) |
| Testing | Chemical Analysis, Tensile Test, Impact Test, Hardness Test, Ultrasonic Testing (Optional) |
| Inspection Standard | EN 10204 3.1 / 3.2 Mill Test Certificate |
| Cutting Service | CNC Cutting, Flame Cutting, Plasma Cutting |
| Surface Treatment | Shot Blasting, Painting, Primer Coating (Optional) |
A514 Gr.F vs S690Q vs Q690D vs S690QL vs Q690E: Difference in low-temperature toughness
This ASTM grade mandates Charpy impact testing at -40°C. Combined Cr-Ni-Cu alloying is adopted to improve matrix toughness, delivering steady impact energy under extreme cold conditions of -40°C. However, hardenability drops sharply when plate thickness exceeds 65 mm, resulting in a drastic plummet of low-temperature toughness for heavy-gauge plates. For this reason, thick plate stock is unavailable for this grade, which is only suitable for cold-climate structural components with thickness ≤65 mm.
No mandatory sub-zero toughness testing is required; only Charpy impact inspection at -20°C ambient temperature is performed. It has the poorest low-temperature performance among the five grades. Outdoor structural application is prohibited when ambient temperature falls below 0°C, as cold cracks tend to form readily in the weld heat-affected zone (HAZ) under low-temperature service. Its only strengths lie in cost advantages under ambient-temperature service and a lower preheat temperature requirement for welding.
A European grade engineered for low-temperature service. Charpy impact testing at -40°C is enforced across all thicknesses. Precision smelting is implemented for desulfurization and dephosphorization of molten steel to minimize internal porosity and inclusion defects. The core low-temperature toughness of heavy plates (80~150 mm) is markedly superior to that of A514 Gr.F.
Specified with a Charpy impact threshold at -20°C. It acts as an intermediate high-strength steel bridging the ambient-temperature S690Q and ultra-low-temperature grades.
Top-tier quenched-and-tempered high-strength steel for low-temperature service under Chinese national standard. Its -40°C Charpy impact properties match S690QL and A514 Gr.F. Clean steel smelting together with controlled rolling & controlled cooling quenching and tempering processes are applied to resolve the drawbacks of long lead times and high customs duties associated with imported steel plates.
A514 Gr.F, S690Q, Q690D, S690QL, Q690E Plate: Typical Practical Application Scenarios
A514 Grade F
Telescopic booms for truck-mounted cranes, heavy-duty mining dump truck cargo bodies, ASTM-standard welded bridges, low-pressure storage tanks for oilfields, OEM structural parts for construction machinery, structural components for special equipment.
S690Q
Main girders for ambient-temperature semi-trailers, ambient-temperature lifting equipment for ports, heavy load-bearing steel beams for factory buildings, ambient-temperature mining machinery for inland Europe.
S690QL
Flanges and main beams for wind turbine towers, engineering vehicles for Arctic mining areas, auxiliary structures for offshore platforms, lifting equipment for cold regions, construction machinery exported to the EU for frigid environments.
Q690D
Main booms of domestic crawler cranes, open-pit coal mine dump trucks, bridge reinforcement structures, high-strength cargo bodies for muck trucks, inland port cranes.
Q690E
Heavy-duty vehicles for open-pit mines, onshore wind turbine towers, embedded anchor parts for cold-climate wind power foundations, domestic nearshore construction machinery, main structural members of cold-region bridges.
Comprehensive Supply Services of GNEE Steel
With more than 18 years of intensive operation in the import and export business of quenched and tempered high-strength steel plates, GNEE Steel maintains abundant stock inventory. The company holds ISO9001 quality certification, CE certification, SGS inspection certification and BV marine survey approval. Our products are exported to over 40 countries including the European Union, North America, Southeast Asia and Kazakhstan all year round. We act as a designated long-term steel supplier for leading construction machinery manufacturers, wind turbine OEM factories and mining equipment fabricators. We are capable of issuing EN 10204 3.1 / 3.2 mill test certificates and arranging third-party witnessed on-site ultrasonic testing.
Full-Chain Supporting Services
- Direct Stock Delivery Full-size plate stock available for A514 Gr.F, S690Q, S690QL, Q690D and Q690E, covering thickness from 8 mm to 150 mm. Custom cut-to-length leveling and wide plate customization are available.
- Precision Machining Services CNC flame / plasma cutting, edge bevel milling, bending, drilling, UT ultrasonic non-destructive testing, MT magnetic particle testing, heat treatment rework.
- Certified Document Support ASTM-compliant mill test reports for US-standard projects, EU CE certification documents, domestic Chinese factory quality guarantee certificates, third-party SGS re-inspection reports for mechanical properties and chemical composition.
We can facilitate both small-batch sample procurement and large-scale centralized purchasing for high-strength steel plates; on-site inspections at the factory can be arranged, and free samples are available for testing.
FAQ
Can A514 Grade F be directly replaced by S690QL?
No, ASTM A514 Grade F cannot be directly replaced by EN 10025-6 S690QL without engineering evaluation, because they belong to different regional standards with distinct chemical and testing rules.
Can S690Q be used for outdoor equipment operating at -25°C in winter?
No, standard S690Q steel should not be used for outdoor equipment operating at -25°C because it poses a significant risk of brittle fracture. Under the European standard EN 10025-6, standard S690Q is only certified and impact-tested down to -20°C (where it must meet a minimum Charpy V-notch impact energy of 30–40 Joules). Operating it at -25°C places the material below its rated transition temperature, where high-strength steel rapidly loses its ductility and can fail catastrophically under stress without warning.
Are Q690D and S690Q considered equivalent steels?
Yes, Q690D and S690Q are considered technical equivalents, representing high-strength quenched and tempered structural steels with a minimum yield strength of 690 MPa and matching impact test requirements at -20°C. However, the impact energy requirements differ (Q690D: average ≥47 J vs. S690Q: ≥30 J), and they fall under two separate acceptance systems: GB/T 16270 and EN 10025-6.
What is the maximum available thickness for A514 Grade F? What is the quality of the heavy plates?
The maximum available thickness for ASTM A514 Grade F steel plate is 2 1/2 inches (2.5 inches or 65 mm) under standard specifications, though some structural profiles or modified specs may map related sub-grades up to 6 inches. These heavy plates are of high-strength, quenched and tempered alloy structural quality.
