Casio shows heavy mettle

It's surprising the G in Casio's iconic G-Shock doesn't stand for Guantanamo because a visit to its birthplace at Hamura R&D Centre, just outside metropolitan Tokyo, reveals a series of stress tests it undergoes to earn it itself the tag as the world's toughest watch.

In one room, a 5kg mallet is launched, pendulum-style, towards the head of a prototype to test for impact. Unsurprisingly, the watch survives unscathed but a cushion which it is flung towards doesn't and is starting to fall apart. The test is repeated 50 times before it's transported to another space where the prototype is attached to a special machine to simulate a fall from 10m for the same number of times.

That's not all, a centrifugal force and vibration test makes sure the watch stays in one piece even under the most extreme of conditions. When all that is done, it's put on another special device with a cloth rubbing against the resin 24-7 for a full week to test the resin's durability.