A steel version of Velcro that is strong enough to hold together buildings has been developed by German scientists.The new invention, called Metaklett, uses the same hook-and-loop fastening system as Velcro but can support loads of up to 35 tonnes per square metre at temperatures as high as 1,472F (800C). Like the popular fabric fastener, Metaklett is designed to be peeled apart and reused, making it a potentially useful and cost-effective engineering component.