All spiders produce silk, but not all silk are created equal. A single spider can produce as many as seven different types of silks, each with its own purpose, such as for prey capture, web construction, or alarm lines. As fragile as they seem, spider silk is actually a biological marvel as they are tough, flexible, and extremely stable.
Some researchers even claim that spider silk is tougher than steel. How so? Spider silk has high tensile strength - that is, the ability to absorb a lot of stress before breaking. For one variety of spider silk, the tensile strength is about 1 Gpa, a unit of measuring force per unit area. By comparison, the tensile strength of steel ranges from 0.2 Gpa to 2 Gpa.
The remarkable mechanical properties of silk make this material highly versatile but extremely difficult to replicate in synthetic form. Scientists know the proteins that make up silk, but they've yet to rearrange it in the same way as spiders.
