You can tell how old some coins are by testing them with a magnet. 5p and 10p coins made before January 2012 are not magnetic. 5p and 10p coins made after January 2012 are magnetic. This is ...

Sagawa’s sintering process made for stronger magnets, with twice the strength of the samarium–cobalt magnets. In contrast, Croat’s melt spinning method allowed for a cheaper manufacturing ...