…and space elevator cables - but alas, for that an even stronger material is needed. :)

The toughest spider silk, made by Darwin’s bark spider, allows the critters to weave webs over a river. If Kevlar as a known quantity has a tensile strength of 3.6 GPa, then this material, described as 10 times tougher, would be 36 GPa. Carbon nanotubes are 63 GPa, and they are considered insufficient. :(