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Mailspring hide history
Mailspring hide history












The spring is wound up by turning the arbor, and after winding its force turns the arbor the other way to run the clock. In many clocks, the outer end is attached to a stationary post. The mainspring is coiled around an axle called the arbor, with the inner end hooked to it. The semi-reverse and reverse types provide extra force at the end of the running period, when the spring is almost out of energy, in order to keep the timepiece running at a constant rate to the end. Reverse (resilient): the outer end of the spring is coiled in the reverse direction for one or more turns (exceeding 360°).Semi-reverse: The outer end of the spring is coiled in the reverse direction for less than one turn (less than 360°).Spiral coiled: These are coiled in the same direction throughout, in a simple spiral.In their relaxed form, mainsprings are made in three distinct shapes: Some of them are also practically non- magnetic. They are less subject to permanent bending (becoming 'tired') and there is scarcely any risk of their breaking. Known to watchmakers as 'white metal' springs (as opposed to blued carbon steel), these are stainless and have a higher elastic limit. Since 1945, carbon steel alloys have been increasingly superseded by newer special alloys ( iron, nickel and chromium with the addition of cobalt, molybdenum, or beryllium), and also by cold-rolled alloys ('structural hardening'). Clock mainsprings are similar to watch springs, only larger. 8-Day movements, used in clocks meant to be wound weekly, provide power for at least 192 hours but use longer mainsprings and bigger barrels. This is the normal standard for hand-wound as well as self-winding watches.

mailspring hide history

24 hours between daily windings with a power-reserve of 12 to 16 hours, in case the owner is late winding the watch. The mainspring in the common 1-day movement is calculated to enable the watch to run for 36 to 40 hours, i.e. Elgin pocketwatch mainsprings from around 1910, showing the three types (l-r): spiral, semi-reverse, reverse.Ī modern watch mainspring is a long strip of hardened and blued steel, or specialised steel alloy, 20–30 cm long and 0.05-0.2 mm thick.














Mailspring hide history