Is S690QL steel hard to drill?

Is S690QL steel hard to drill?

Yes, S690QL steel is hard to drill because it's a high-strength, quenched & tempered (Q+T) steel, requiring specialized, tough drill bits (cobalt/carbide) and proper techniques (slow speed, cutting fluid, ample pressure) to prevent dulling, overheating, and breakage, though its good machinability compared to some stainless grades is noted with the right setup.

S690QL is a high strength quenched and tempered steel grade that complies to steel specification EN 10025. The designation S690QL refers to a minimum yield strength of 690 MPa.

The combination of good availability and pricing and high strength combined with ease of fabrication has made S690QL steel plate a popular grade for both mobile applications such as cranes and lifting equipment and fixed steel structures. The high strength nature of this steel means that structures can be designed lighter and for mobile application this means increase in payload and operational efficiency.

S690QL structural steel. It is renowned for its impressive tensile strength and toughness, making it suitable for heavy-duty applications. The "S" stands for structural steel, "690" represents the minimum yield strength in megapascals (MPa), and "QL" indicates the material is of high quality, with excellent low-temperature toughness.

S690QL is an ultra-high-strength, quenched and tempered structural steel (EN 10025 standard) known for its exceptional strength (minimum 690 MPa yield), toughness, abrasion resistance, and good weldability, ideal for heavy-duty applications like cranes, heavy vehicles, and construction where lighter designs and high performance are needed, even in cold environments.

Key Characteristics:

S (Structural): Indicates it's a steel for structural purposes.

690: Denotes a minimum yield strength of 690 Megapascals (MPa).

QL (Quenched & Low-temperature): Shows it's heat-treated (quenched and tempered) for high strength and excellent toughness, even at low temperatures.

High Strength-to-Weight Ratio: Allows for lighter structures, increasing payload in mobile applications.

Toughness: Resists impact and fatigue, with good performance down to -40°C or lower.

Weldability: Low carbon content and careful production ensure good weldability, though preheating is often recommended.

Common Applications:

-Cranes and lifting equipment

-Heavy-duty transport and armored vehicles

-Bridges and large steel structures

-Mining and construction machinery

-Energy sector components

What is the difference between s690ql and hardox 400 ?

S690QL is a high-yield structural steel with excellent weldability and formability for general construction, while Hardox 400 is a premium wear-resistant (AR) steel, significantly harder (370-430 HBW) and tougher for extreme abrasion/impact in heavy machinery, making S690QL better for load-bearing structures and Hardox 400 for protective linings. The main difference lies in their primary function: S690QL for structural strength and Hardox 400 for wear protection, with Hardox 400 prioritizing hardness over typical S690QL yield strength.

What is S690QL high speed steel?

S690QL is an ultra-high-strength structural steel, not high-speed steel, known for its exceptional yield strength (minimum 690 MPa) achieved through quenching and tempering (the 'Q' and 'L' in its name), making it ideal for lighter, stronger structures in cranes, lifting equipment, bridges, and heavy machinery, offering excellent weldability, toughness, and low-temperature performance for demanding heavy-duty applications.

What is the composition of S690QL?

S690QL is a high-strength structural steel (EN 10025-6) known for its minimum 690 MPa yield strength after quenching and tempering, with key alloying elements like Carbon, Manganese, Silicon, Chromium, Molybdenum, Nickel, and microalloying elements (Nb, Ti, V, Zr) that enhance strength and toughness, making it ideal for heavy machinery, cranes, and construction. Its composition includes typical limits for C (0.2%), Si (0.8%), Mn (1.7%), P (0.025%), S (0.015%), with additions of Cr (1.5%), Mo (0.7%), Ni (2%), Nb (0.06%), Ti (0.05%), V (0.12%), and Zr (0.15%)

Equivalent grades of steel S690QL (1.8928)

S690QL - Chemical Composition

S690QL - Mechanical Properties

S690QL - V Notch Impact Testing

1What is S690QL grade steel?

S690QL is a high-yield strength, quenched and tempered structural steel (EN 10025 standard) known for its excellent strength (minimum 690 MPa yield), toughness, weldability, and low-temperature performance, enabling lighter, more efficient designs in heavy-duty applications like cranes, mobile equipment, bridges, and construction machinery. The "S" means structural, "690" is the yield strength in MPa, and "QL" signifies high quality and toughness, especially at low temperatures.

2What is the effective use of high strength S690QL steel in construction?

S690QL steel's effective use in construction leverages its high strength (690 MPa yield) and toughness for lighter, stronger, and more efficient designs in heavily loaded structures like bridges, high-rise buildings, wind turbines, and offshore platforms. It reduces self-weight, minimizing foundation loads and material use, while its excellent weldability, formability, and resistance to fatigue and abrasion suit demanding applications, including heavy machinery and seismic zones.

3What is S690QL standard?

S690QL is a European standard (EN 10025-6) for ultra-high-strength structural steel, known for its excellent combination of high yield strength (minimum 690 MPa), toughness, and weldability, achieved through a quenched and tempered (Q+T) heat treatment. It's used in demanding applications like cranes, heavy machinery, bridges, and wind turbines, allowing for lighter, more efficient designs with increased payload capacity.

4What is the machinability of S690QL?

S690QL is a high-strength steel (HSS) that offers good overall machinability for its class, especially considering its high yield strength (690 MPa), with easier cutting and forming than expected for such a strong material, though it requires more power than standard carbon steels and careful heat treatment considerations for welding, benefiting from lower heat input and pre/interpass temperatures.

5Is S690QL steel hard to drill ?

Yes, drilling S690QL (a high-strength quenched and tempered steel) is harder than standard mild steel because of its high yield strength (690 MPa) and hardness, requiring specialized tools like carbide or cobalt bits, slower speeds, and proper cooling to prevent bit wear and maintain material integrity, but it's a standard fabrication process if done correctly.

6Is S690QL carbon steel?

Yes, S690QL is considered a high-strength structural steel that contains carbon, but it's more accurately described as a low-alloy, high-yield (HY) steel due to controlled additions of other elements (like Manganese, Silicon, Chromium, Molybdenum) for enhanced properties, making it stronger and tougher than plain carbon steel, especially for demanding, cold-temperature applications.

7What is the hardness of S690QL?

S690QL steel typically has a Brinell hardness around 235-295 HBW, though it can reach up to 414 HBW, with actual hardness varying by thickness and heat treatment, often tested at approximately 270 HV10 (Vickers) for base metal, offering a good balance of strength and toughness for high-load applications.

Contact now

Full specification and details are available on request. The above information is provided for guidance purposes only. For specific design requirements please contact our technical sales staff