List of Modulus of Longitudinal Elasticity (Young's Modulus)｜Thorough explanation of values for metals, resins, and ceramics

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Have you ever had trouble selecting an accurate value for the Young's modulus?　　The values may differ slightly depending on the data at hand or on the website, and you may be at a loss as to which value to believe.

In particular, a reliable list of Young's modulus is indispensable in today's design field, where a wide variety of materials are being handled, from metals to resins and even ceramics.　Using incorrect values can shake the reliability of analysis results and lead to unexpected design problems.

In this article, we have gathered a comprehensive list of specific values for various materials for designers seeking a "Young's Modulus List".　　And it is not just a list of numerical values, but a step-by-step information note on why the value is obtained and what kind of attention is required in design.

Physical meaning and basic principles of the modulus of longitudinal elasticity (Young's modulus)

What is the modulus of longitudinal elasticity (Young's modulus)? Physical property value indicating stiffness

The modulus of elasticity (Young's modulus) is one of the most basic physical properties that indicate a material's "stiffness," or resistance to deformation.　It is an indicator of how resistant a material is to deformation when a tensile or compressive force is applied to it.　　The higher the Young's modulus value, the stiffer and less deformable the material.　　Conversely, a material with a low Young's modulus value is flexible and easily deformable.

This property is derived from the strength of the bonding forces between the atoms that make up the material.　　Therefore, Young's modulus is independent of geometry and is unique to the material.

The Young's modulus of steel is the standard for mechanical design, and is approximately 205 GPa. Using this value as a reference, understanding the relative resistance to deformation of other materials is the first step in selecting materials for the initial design.

Stress and strain, relationship to Hooke's law

To understand the longitudinal modulus of elasticity (Young's modulus), two concepts are essential: stress and strain.　When an external force is applied to a material, a resistance force is generated inside the material to resist the force.　　This resistance force per unit area is "stress (σ).　　Strain (ε) indicates the rate at which the material is deformed by the applied force, i.e., how much it expands or contracts relative to its original length.

In the "elastic range," the range in which a material returns to its original state after being subjected to a force, there is a proportional relationship between stress and strain.　　This is called Hooke's law. Young's modulus (E) is the constant of proportionality in this proportional relationship and is expressed by the following simple equation

σ = E × ε

This is conceptually the same as the law that describes the elongation of a spring (F = kx).　　If we consider that stress σ corresponds to force F, strain ε corresponds to elongation x, and Young's modulus E corresponds to spring constant k, we can intuitively understand that Young's modulus is an indicator of the inherent "hardness" or "spring strength" of a material.

Units and conversion formulas (GPa and N/mm²)

The unit of the modulus of longitudinal elasticity (Young's modulus) is expressed in pascals (Pa), the same unit of pressure as stress.　　However, since the Young's modulus of actual industrial materials can be very large, gigapascals (GPa) or megapascals (MPa) are usually used.

In particular, in mechanical design and CAE analysis practice, newtons (N) are often used for force and millimeters (mm) for length, in which case the units for stress and Young's modulus are N/mm².　　This N/mm² is exactly the same magnitude as MPa. It is important to remember the following relational equation accurately to avoid making mistakes when converting units.

• 1 GPa = 1,000 MPa
• 1 MPa = 1 N/mm²

Therefore, from these two equations, the relationship between GPa and N/mm² is as follows

• 1 GPa = 1,000 N/mm²

For example, Young's modulus of steel, 205 GPa, is equivalent to 205,000 N/mm².　　This conversion is essential if the material data sheet is listed in GPa but the input to the analysis software requires N/mm².

Difference from transverse modulus of elasticity

Modulus of Longitudinal Elasticity (Young's Modulus)is to indicate the resistance of a material to deformation from "longitudinal" forces that pull or compress it.

On the other hand, there is also a value that indicates the elasticity of a material called the modulus of transverse elasticity (G).　　This is also called the shear modulus or modulus of rigidity, and indicates the resistance of a material to deformation from "shear forces" such as twisting or shifting.

While the longitudinal modulus of elasticity (Young's modulus) plays a central role in the calculation of "bending" or "expansion and contraction" of a member, the transverse modulus of elasticity is used in the calculation of "torsion".　　Thus,Two completely different physical properties that indicate resistance to different kinds of deformationIt is.

However, for isotropic materials (materials that have the same properties in all directions) such as steel and aluminum, Young's modulus (E), the modulus of transverse elasticity (G), and how much the material shrinks in the transverse direction when it is pulled "Poisson's ratio (ν)The following relationship holds between

G = E / 2(1 + ν)

As can be seen from this formula, if two of the three values are known, the remaining one can be obtained by calculation.　　However, since they are just different physical quantities, care must be taken not to use the wrong input values in CAE analysis, etc.

Critical difference from strength and hardness

In the design field, the terms "stiffness," "strength," and "hardness" are frequently used,Confusing these meanings can lead to design errors and must be strictly distinguished.

• Stiffness: A measure of how resistant a material is to deformation under load, which is determined by Young's modulus.　Stiffness is important if the design challenge is to reduce deflection.
• Strength: Strength is a measure of how much force a material can withstand without breaking.　Strength is evaluated by yield point and tensile strength, and is important if the design issue is "unbreakable.
• Hardness: An indicator of a material's "surface scratch resistance. This is important for sliding parts that require abrasion resistance.　Some materials arehardening　Hardness can be increased by

Most importantly, there is no direct correlation between these properties.　　For example, glass is very rigid, but brittle and not strong enough to resist impact.　　Conversely, high-tensile steel is stronger than ordinary steel, but has about the same Young's modulus, so it is no less susceptible to deflection.　　The key to proper material selection is to correctly determine whether the design problem is insufficient stiffness or insufficient strength.

List of longitudinal modulus of elasticity (Young's modulus) of metallic materials and comparison of their properties

Longitudinal modulus of elasticity (Young's modulus) of reference iron

In mechanical design, Young's modulus of iron (steel) is the standard value for all materials.　　Young's modulus of most steel materials, including general structural rolled steel (SS400) and carbon steel for machine structural purposes (e.g., S45C), has a value of about 205 GPa (gigapascal).　　This value is a basic physical property that every designer should keep in mind.

A major characteristic of steel materials is that although tensile strength and hardness change significantly with heat treatment such as quenching and tempering, Young's modulus remains almost unchanged.　　This is because Young's modulus is governed by the fundamental property of the material, the bonding force between atoms, and is not easily affected by changes in metallurgical structure.　　This stability allows the Young's modulus of steel to be treated as a reliable constant in many CAE analyses.

However, it should be noted that the Young's modulus of cast iron is lower than that of steel, ranging from 100 to 180 GPa, due to the different microstructure of cast iron, and the variation in Young's modulus is larger than that of steel.　　If the design object is cast iron, care should be taken not to enter values in the same way as for steel.

Longitudinal modulus of elasticity (Young's modulus) of commonly used stainless steel

Stainless steel (SUS) is used in a variety of products because of its excellent corrosion resistance, and its Young's modulus is almost equal to that of steel.　　Typical austenitic SUS304 has a Young's modulus in the range of about 193 to 200 GPa.　　SUS316L, to which molybdenum is added to improve corrosion resistance, has a Young's modulus of about 193 GPa, while the less expensive ferrite-based SUS430 has a Young's modulus of about 200 GPa.

Therefore,When the material of a structural member is changed from carbon steel to stainless steel, corrosion resistance and strength are improved, but stiffness, a measure of "resistance to deflection," can be considered to remain virtually unchanged.If reducing deflection is a design issue, it will be difficult to solve simply by changing materials to stainless steel.

Thus, understanding that Young's modulus is a physical property independent of strength and corrosion resistance is key to proper material selection.

Longitudinal modulus of elasticity (Young's modulus) of lightweight aluminum

Young's modulus of aluminum alloys is about 70 GPa, about one-third that of steel materials.　　This low value is one of the reasons why aluminum feels "soft.　　If a part with the same shape is replaced from steel to aluminum, the amount of deflection will be about three times larger by simple calculation.

On the other hand, aluminum's major advantage is its light weight. Its density is also about one-third that of steel (about 2.7 g/cm³), so when compared using the index of "specific stiffness," which is Young's modulus divided by density, it is at about the same level as steel.　　This is,It means that when designing a part with the same mass of material, it is possible to achieve rigidity equivalent to or greater than that of steel by using a shape with a larger cross-sectional area, for example.This characteristic is the reason why aluminum is widely used in fields such as aircraft and automotive parts, where weight reduction is a top priority.

Even high-strength duralumin (A2017, A2024) and ultra-super duralumin (A7075) have a Young's modulus of around 72 GPa, not much different from general-purpose aluminum alloys (A5052, A6061, etc.).This is a typical example of how high strength does not necessarily mean high rigidity.

Longitudinal modulus of elasticity (Young's modulus) of high-strength titanium

Titanium alloys have a Young's modulus of around 110 GPa, which is somewhere between iron and aluminum.　With a density of approximately 60% lighter than steel, but with high strength, it has excellent specific strength and specific rigidity, and is used in aerospace and high-performance sporting goods.

When working with titanium alloys, designers should be aware that Young's modulus can vary greatly in the range of 80 to 120 GPa, depending on the type of alloy and heat treatment conditions.　　This is because titanium tends to change its crystalline structure with temperature, and the physical properties can be intentionally altered by controlling the ratio of these phases through heat treatment.

Therefore, in CAE analysis using high-performance titanium alloys, the reliability of the analysis results may be compromised if the heat treatment conditions of the material used are not accurately understood and a Young's modulus value that matches these conditions is not entered, in addition to using representative values from the catalog provided by the material manufacturer.

Longitudinal modulus of elasticity (Young's modulus) of copper, brass, and magnesium

Young's modulus of other major metallic materials is presented here.

Copper and copper alloys

Pure copper (C1020, C1100), which has excellent electrical and thermal conductivity, has a Young's modulus of approximately 110 to 130 GPa.　Brass (e.g., C3604), an alloy of copper and zinc, has values in the range of about 97 to 115 GPa, close to those of copper and titanium.

magnesium alloy

The Young's modulus of magnesium alloys (e.g., AZ31B), the lightest of the utility metals, is about 45 GPa, even lower than that of aluminum.　　However, due to its lightness, its specific rigidity is very high, and it is used in situations where extreme weight reduction is required, such as notebook computer chassis and automotive parts.　　However, due to its low rigidity, it is essential to devise a shape such as ribs.

List of Modulus of Elasticity (Young's Modulus) of Resins (Plastics)

Longitudinal modulus of elasticity (Young's modulus) of POM and nylon

Engineering plastics (engineering plastics) are widely used in machine parts as alternative materials to metals. POM (polyacetal) and nylon (polyamide), which are representative among them, are materials with excellent self-lubricating and wear resistance properties.

Young's modulus of these engineering plastics ranges from about 2.7 to 3.2 GPa for POM and 2.5 to 3.5 GPa for nylon.　　This value is nearly two orders of magnitude lower than that of steel materials (approximately 205 GPa) and significantly lower than that of aluminum (approximately 70 GPa).　　This low Young's modulus is the direct cause of the "deflection tendency" of plastic parts compared to metal parts.

As a design note,Young's modulus of resin materials is very temperature dependentThe following is a list of the properties of the product.　　The values listed in the physical properties table are measured at room temperature (23°C),Young's modulus decreases significantly at high temperatures.　Therefore, in strength analysis of plastic parts used at high temperatures, Young's modulus data at operating temperatures must always be used.

Longitudinal modulus of elasticity (Young's modulus) of ABS and polycarbonate

ABS resin and polycarbonate (PC) are also resin materials frequently used in machine parts and housings.

ABS resin has a performance intermediate between that of commodity plastics and engineering plastics, offering an excellent balance of processability and strength. Its Young's modulus is approximately 2.1 to 2.3 GPa.　Polycarbonate, on the other hand, is an engineering plastic characterized by transparency and very high impact resistance. Its Young's modulus is approximately 2.0 to 2.4 GPa, which is close to that of ABS resin.

Like POM and nylon, the rigidity of these resins is much lower than that of metals.　　Therefore, when designing a housing or other components with resins, it is necessary to effectively arrange ribs to suppress deflection, or select reinforced grade materials that are filled with glass fibers to improve Young's modulus itself.

List of Modulus of Elasticity (Young's Modulus) for Ceramics and Glass

Longitudinal modulus of elasticity (Young's modulus) of highly rigid alumina

Fine ceramics are a group of materials with extremely high rigidity that far surpasses metals.　　Alumina (Al₂O₃), a typical example, has a Young's modulus of about 360 to 390 GPa, although the physical properties vary with purity.　　This is nearly twice that of steel, indicating that the material is extremely resistant to deformation.

This very high stiffness is due to the fact that ceramics are composed of strong ionic and covalent bonds.　　Because the atoms are so tightly bound, great forces are required to deform them.

These characteristics have made alumina an indispensable material for applications that absolutely require dimensional stability on the micrometer scale, such as precision stages and arms for semiconductor manufacturing equipment and parts for precision machine tools.

Longitudinal modulus of elasticity (Young's modulus) of tough zirconia

Zirconia (ZrO₂) is a material with unique properties among ceramics.　　Young's modulus is approximately 200 GPa, which is almost equal to that of steel. Although it is less rigid than alumina and silicon carbide, it has a significant feature of extremely high fracture toughness (tenacity) as a ceramic.

Because of this "crack-resistant" property, zirconia is used for scissors, cutter blades, and structural parts that require high strength.　　When dealing with zirconia in CAE analysis, the Young's modulus is close to that of steel, so the amount of deflection under the same load is expected to be about the same, but the allowable stress and fracture mechanism are completely different, so care must be taken when selecting a material model.

Longitudinal modulus of elasticity (Young's modulus) of hard silicon carbide

Silicon carbide (SiC) is one of the stiffest and hardest materials among industrially used ceramics.　Its Young's modulus reaches about 430 to 440 GPa, even higher than that of alumina.

In addition to its extremely high rigidity, it is lightweight (less than half the density of steel) and has excellent heat resistance, making it suitable for applications requiring high dimensional stability in harsh environments, such as parts of semiconductor manufacturing equipment and sliding parts of machinery rotating at high speed.　　However, since it is extremely hard and brittle, it is essential to take shape into consideration in design to avoid stress concentration.

Longitudinal modulus of elasticity (Young's modulus) of transparent glass

The Young's modulus of commonly used soda-lime glass is about 72 GPa.　　This value is about the same as that of aluminum alloys.　　This means that glass and aluminum will deflect with the same amount of force if the plates are of the same shape.

However, the critical difference between the two is the behavior leading to fracture. While aluminum fractures after undergoing significant deformation, glass undergoes "brittle fracture" in which it suddenly breaks down with little deformation.

When dealing with glass in strength analysis, one should not just look at Young's modulus values and consider it the same as aluminum. The stress intensity factor and other factors based on fracture mechanics must be evaluated, and the design must take into account the risk of crack propagation from even the smallest flaw.

Correctly use the list of longitudinal modulus of elasticity (Young's modulus) for analysis

Throughout this article, we have discussed Young's modulus of major industrial materials.　　It is important to properly utilize the knowledge gained here in order to improve the accuracy of strength analysis and achieve better product design. Finally, we will summarize some important points in dealing with the Young's modulus list and useful websites for obtaining information on Young's modulus.

• The modulus of elasticity (Young's modulus) is a physical property that indicates the stiffness (resistance to deformation) of a material.
• Indicators different from strength (resistance to breakage) and hardness (resistance to surface scratching)
• In mechanical design, about 205 GPa of steel material is the standard for all
• Young's modulus of steel is almost constant even if the strength is changed by heat treatment
• Young's modulus of stainless steel is almost equal to that of steel
• Young's modulus of aluminum alloys is about one-third lower than that of steel
• Aluminum is lightweight and has the same level of specific stiffness (E/ρ) as steel
• Titanium alloys have a Young's modulus intermediate between iron and aluminum
• Note that the Young's modulus of titanium varies greatly depending on heat treatment
• Young's modulus of resins (plastics) is nearly two orders of magnitude lower than that of metals
• Young's modulus of resins is highly dependent on temperature, so check the value at the operating temperature.
• Ceramics have a high Young's modulus that significantly exceeds that of metals
• Alumina and silicon carbide exhibit extremely high rigidity
• Zirconia combines a Young's modulus equivalent to steel with high toughness
• Young's modulus of glass is equivalent to aluminum, but beware of brittle fracture

• JIS Z 2280 (Japanese Industrial Standard)
  • URL:. https://webdesk.jsa.or.jp/books/W11M0090/index/?bunsyo_id=JIS+Z+2280%3A1993
  • Description: (in Japanese only) This is an official document on Young's modulus test methods for metallic materials established by the Japanese Industrial Standards (JIS). It is one of the most authoritative sources of information, as it provides detailed standards for obtaining reliable data, including measurement methods for static and dynamic Young's modulus and specimen specifications.  
• Cybernet Systems Corporation (ANSYS Learning Room)
  • URL:. https://www.cybernet.co.jp/ansys/learning/glossary/youngritsu/
  • Description: (in Japanese only) This is a technical explanation page operated by Cybernet, a major CAE (computer-aided engineering) software vendor. From the viewpoint directly related to practical strength analysis, the definition of Young's modulus, its meaning in the stress-strain curve, and the relationship with related physical properties (Poisson's ratio, shear modulus, etc.) are explained concisely and precisely.  
• Kyocera Corporation (Fine Ceramics Site)
  • URL:. https://www.kyocera.co.jp/prdct/fc/material-property/property/stiffness/index.html
  • Description: (in Japanese only) This is a page where Kyocera, a major ceramics manufacturer, explains rigidity (Young's modulus) as a characteristic of its products. Specific Young's modulus values for highly rigid materials such as alumina and silicon carbide, which far surpass metals, can be confirmed from the manufacturer's point of view    
• The Japan Society of Mechanical Engineers (JSME)
  • URL:. https://www.jsme.or.jp/
  • Description: (in Japanese only) It is the most authoritative academic organization in the field of mechanical engineering in Japan. The journals and handbooks published by the society serve as the standard for definitions and research on mechanics of materials, including Young's modulus. The site serves as a starting point for obtaining the latest research trends and more specialized knowledge.  
• Yupo Corporation (Technical Column)
  • URL:. https://service.yupo.com/release/column/young-modulus/
  • Description: (in Japanese only) This page by Yupo Corporation, a synthetic paper manufacturer, explains Young's modulus as a physical property of materials in a very easy-to-understand manner. It is ideal for learning basic concepts such as the relationship with stress and strain, Hooke's law, and the difference from Poisson's ratio, and the values of various materials are also compared!

That's it.