Megapascal

The megapascal (symbol MPa) is the SI unit of pressure, stress, and material strength. It equals one million pascals (1 MPa = 10^6 Pa), with a pascal defined as one newton per square meter. Because pascals are small for many engineering applications, the megapascal is widely used to express higher pressures or stresses. The MPa is also equivalent to 1 newton per square millimeter (N/mm^2) and to 0.001 gigapascals (GPa).

Conversions commonly used with the MPa include: 1 MPa ≈ 145.038 psi; 1 MPa = 10 bar; and 1 atm ≈ 0.101325 MPa (about 9.869 atm). These relationships help bridge SI units with customary units used in various industries.

Applications of the MPa span many fields. It is used to specify the strength and stiffness of materials (such as yield strength and tensile strength of steels), the stresses in structural components, and the pressures in hydraulic and pneumatic systems. In geology and geotechnical engineering, rock and soil stresses are often reported in MPa.

Typical magnitudes illustrate its range. A passenger car tire operates at roughly 0.2–0.3 MPa (about 2–3 bar). High-strength steels and engineered alloys can exhibit yield strengths from hundreds up to about a thousand MPa, depending on composition and treatment. The MPa thus covers a broad spectrum of practical engineering pressures.