What's so special about a piece of coiled wire? Plenty. Our spring is made of nitinol, an amazing metal that can be twisted or straightened but will always return to its original shape when dipped into hot water (~50°C). Talk about discrepant events - this wire is practically magic! An alloy of nickel and titanium, nitinol (Ni-Ti) falls into a sophisticated class of materials known as shape memory alloys that "remember" their original shape. Perfect for classroom demonstrations. Comes with a Teacher's Guide. Wire is 0.75 mm thick, with a 20 mm inner diameter and 45 cm overall length. If you're looking for straight memory wire, please see our Nitinol Memory Wire (HS-6
), sold by the foot or in 3 inch sample packs.