A clip of metal or plastic which attaches the luff of a sail to a stay. Most staysails (vulgarly called ‘jibs’) are hanked to their forestays with piston hanks, taking the form of P-shaped hooks closed with a spring-loaded plunger. But there are moulded nylon hanks and hanks made of tape which are held by press-studs. The latter are surprisingly rare, considering how neat and light they are.