In Episode 9 of No Dumb Questions, we explain tensile strength, a fundamental material property describing how much force is required to pull a material apart.
Tensile strength is measured in pounds per square inch (PSI) or pascals (Newtons per square meter). Knowing a material’s tensile strength allows engineers to estimate the total break strength of wire conductors or structural cabling components based on cross-sectional area. For example, a one-inch square bar made of a material with a 1,000 PSI tensile strength can theoretically support 1,000 pounds of pull force before failing.
Materials often exhibit a range of tensile strengths. In metals like copper or aluminum, lower tensile strength corresponds to soft, ductile conductors, while higher tensile strength indicates work-hardened, rigid metals. However, as metals reach extremely high tensile strength levels, they become brittle. Tensile strength and metal hardness can be precisely controlled through mechanical work hardening during drawing and thermal annealing processes to balance break strength with flex life.
Key Technical Takeaways
- Definition: Tensile strength measures the maximum pulling force a material can withstand before breaking.
- Units of Measurement: Expressed in PSI (pounds per square inch) or Pascals (N/m²).
- Break Strength Calculation: Total pull strength is calculated by multiplying tensile strength by cross-sectional area.
- Soft vs. Hard Metals: Lower tensile strength yields softer, more flexible conductors; higher tensile strength increases rigidity but can make metal brittle.
- Process Control: Tensile properties are tailored using work hardening during wire drawing and thermal annealing heat treatments.
More great content here –> Episode 10: What impact does jacket wall thickness have on a cable?
Episode 9 Transcript – What is Tensile Strength?
Welcome to No Dumb Questions
Hi, my name is Tom. Welcome to No Dumb Questions. Today we’ll be talking about tensile strength.
What is Tensile Strength?
Tensile strength is a material property which describes how much force it requires to pull apart a material. Tensile strength is measured in psi (pounds per square inch) or pascals, which is newtons per square meter. It’s important to know the tensile strength of the material, because it allows us to estimate the break strength of essentially anything that uses that material.
So, for example, if we had a one inch square bar made of a material that had a 1000 psi tensile strength, because we know the cross-section is one square inch and the tensile strength is 1,000 pounds per square inch, we know that that bar is essentially good for, or could pull 1,000 pounds.
Soft vs. Hard Metals & Work Hardening
Many materials have a range of tensile strength. Metals on the low end are considered soft, and on the high end are considered hard. As they reach the very high end of their tensile strength, they become brittle. The hardness of a metal can be controlled by annealing it and work hardening it.
See more about that in my video about annealing on No Dumb Questions.
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