Coefficient of Thermal Expansion (CTE) values verified against authoritative datasheets and engineering references. Values are typical for materials at room temperature (20-25°C) and may vary with temperature, grade, and processing.
Primary Datasheet Sources
- MatWeb - Material property database with manufacturer datasheets
- Engineering Toolbox - Engineering materials reference database
- ASM Material Data Sheets - ASM International material specifications
- SpecialChem - Plastics material properties database
Comprehensive Material Reference Table
All materials in the calculator database with verified CTE sources.
| Material | CTE (µm/m·°C) | Source |
|---|---|---|
| METALS | ||
| Aluminum 3003 | 22.5-23.6 | Engineering Toolbox |
| Aluminum 6061 | 23.2-23.6 | MatWeb |
| Brass (Yellow) | 19.0-20.5 | Engineering Toolbox |
| Brass (Red) | 18.0-19.5 | Engineering Toolbox |
| Bronze (Commercial) | 17.5-18.5 | MatWeb (C93200) |
| Cast Iron, Gray | 10.5-11.2 | Engineering Toolbox |
| Cast Iron, Ductile | 11.0-12.0 | Engineering Toolbox |
| Copper (C10100/C11000) | 16.5-17.2 | MatWeb (C11000) |
| Gold | 14.0-14.3 | MatWeb: Elements |
| Lead | 28.0-30.0 | MatWeb: Elements |
| Magnesium | 25.0-26.5 | MatWeb: Elements |
| Nickel | 12.5-13.5 | MatWeb: Elements |
| Platinum | 8.8-9.2 | MatWeb: Elements |
| Silver | 18.5-19.7 | MatWeb: Elements |
| Steel, Carbon (1020) | 11.5-12.0 | MatWeb |
| Steel, Carbon (4140) | 11.5-13.0 | MatWeb |
| Steel, Stainless 304 | 17.2-17.3 | MatWeb |
| Steel, Stainless 316 | 15.5-16.5 | MatWeb |
| Steel, Tool A2 | 11.3-12.0 | Engineering Toolbox |
| Steel, Tool D2 | 10.2-10.8 | MatWeb |
| Titanium Grade 2 | 8.4-8.8 | Engineering Toolbox |
| Zinc | 29.0-31.0 | MatWeb: Elements |
| PLASTICS | ||
| ABS (Generic) | 75-95 | Professional Plastics |
| Acetal (POM) | 80-85 | Professional Plastics |
| Acrylic (PMMA) | 70-75 | Professional Plastics |
| CPVC | 69.5-80 | MatWeb (Corzan) |
| HDPE | 100-200 | MatWeb (Pipe) |
| LDPE | 100-240 | MatWeb (Sheet) |
| Nylon 6 | 70-85 | Professional Plastics |
| Nylon 6/6 | 70-85 | Professional Plastics |
| PEEK | 47-108 | MatWeb (450G) |
| Polybutylene (PB) | 120-140 | Engineering Toolbox |
| Polycarbonate (PC) | 65-70 | Professional Plastics |
| Polypropylene (PP) | 100-150 | Professional Plastics |
| Polystyrene (PS) | 65-75 | Professional Plastics |
| PET (Polyester) | 65-75 | Engineering Toolbox |
| PTFE (Teflon) | 100-165 | MatWeb |
| PVA | 80-90 | Engineering Toolbox |
| PVC (Rigid) | 75-85 | MatWeb (Piping) |
| PVDF | 100-200 | Technical Datasheet |
| WOOD (Anisotropic) | ||
| Fir (Parallel) | 3.5-4.2 | MST: Wood CTE |
| Fir (Perpendicular) | 28-38 | MST: Wood CTE |
| Oak (Parallel) | 4.5-5.5 | USDA Wood Handbook |
| Oak (Perpendicular) | 45-65 | Engineering Toolbox |
| Pine (Parallel) | 4.5-5.5 | Engineering Toolbox |
| Pine (Perpendicular) | 30-40 | Springer: J Wood Sci |
| CERAMICS & OTHERS | ||
| Alumina (99%) | 7.5-8.7 | Engineering Toolbox |
| Concrete | 10-14 | FHWA Research |
| Glass, Borosilicate | 3.25-3.3 | SCHOTT |
| Glass, Soda Lime | 8.5-9.5 | Engineering Toolbox |
| Quartz, Fused | 0.55-0.59 | Goodfellow |
General Reference Sources
Important Notes
- CTE values vary by temperature range - values shown are typically for 20-100°C
- Specific alloy grades may differ from generic material listings
- Fillers and reinforcements (e.g., glass fiber) significantly reduce CTE
- Wood is highly anisotropic - see WOOD section above for parallel vs perpendicular values
- Always consult manufacturer datasheets for critical applications
What is Linear Thermal Expansion?
Put simply: When things get hot, they get longer.
Notice in the animation above how the "Hot" atoms vibrate more aggressively? To maintain that movement without colliding, they push their neighbors further away (shown by the larger gaps).
Across billions of atoms, these microscopic gaps add up to a measurable change in length.
At the atomic level, heat is just energy. As a material gets warmer, its atoms vibrate more vigorously. This vibration creates "personal space" issues - the atoms push their neighbors slightly further away. Across billions of atoms, these microscopic pushes add up to a noticeable change in length. This is why bridges have "expansion joints" (gaps with teeth) and why power lines sag more on hot summer days.
Understanding the Formula
Engineers use a simple formula to estimate this growth:
ΔL = α · L₀ · ΔT
- ΔL (Delta L): The change in length (how much it grew).
- α (Alpha): The Coefficient of Thermal Expansion. This is a material property that says "how sensitive is this stuff to heat?"
- L₀: The original starting length.
- ΔT (Delta T): The change in temperature (Final - Initial).