"Spider silk is famous for its amazing toughness, and until recently a tensile strength of 1.3 gigapascals (GPa) was enough to earn it the title of strongest natural material. However, researchers report online today in the Journal of the Royal Society Interface that the record books need to be updated to properly recognize the incredible strength of the limpet teeth. Marine snails known as limpets (Patella vulgata) spend most of their lives scraping a set of small teeth along rocks in shallow ocean waters, looking for food. The constant grinding would be enough to quickly reduce most natural materials to nubs, but the limpets’ teeth boast a tensile strength of between 3 and 6.5 GPa..."Microphotograph via the Washington Post, which offers these observations:
The teeth also bested several man-made materials, including Kevlar, a synthetic fiber used to make bulletproof vests and puncture-proof tires. The amount of weight it can withstand, Barber told the BBC, can be compared to a strand of spaghetti used to hold up more than 3,300 pounds, the weight of an adult female hippopotamus.The original publication is here.
Their secret is in the size of their fibers, which are 1/100th the diameter of a human hair. The ultra-thin filaments avoid the holes and defects that plague larger strands — including man-made carbon fibers — meaning any structure they compose is also flawless, regardless of how big it gets.