How much one hair can hold

A single human hair is quite strong in tension, but the claim that one strand can hold 3 kg is an overstatement. A study measured hair tensile strength at about 150–270 MPa, with results depending on humidity, loading rate, and fiber properties. For a typical 70 μm hair, that corresponds to roughly 60–100 g-force before breaking in a simplified estimate—not a universal rated capacity.