One wouldn’t think the minutiae of a handyman’s toolbox could enthrall the jewellery world, yet it does. In the 1970s, Aldo Cipullo designed the first nail bracelet for CARTIER, and for 2017, the Juste un Clou (“just a nail”) concept returns as a necklace. New is the Écrou de Cartier, which resembles a screw and is bent into a bangle with six bolts threaded onto it. Meanwhile, TIFFANY & CO.’s HardWear collection offers a smooth modernist version of the sturdy chain bolt in a necklace, a bracelet and earrings. Time for a lockdown.