The Workhorse
The 2824, the best known of the family, is nearly 5mm thick and 25.6mm in diameter. Clearly, it’s self-winding, with that oscillating weight spinning up a 38-hour power reserve. The balance runs at 28,800 bph (4Hz) and the movement hacks. It has 25-jeweled bearings.
What makes the whole thing rather more complex is ETA’s habit of offering movements in three or four grades—standard, elabore, top and chronometer. To be fair, the principal differences are in the level
To be fair, the principal differences are in the level of regulation and the quality of mainspring, hairspring and shock system. The cooking movements get Nivarox hairsprings, and the smarter movements get the more temperature-stable Anachron. Likewise, the more basic models have Nivaflex NO mainsprings with their big-house-on-the-hill cousins being powered by Nivaflex NM springs.
The difference? It’s a challenge working out why NM is better than NO. Both mainsprings have the same metallurgical breakdown: 45% cobalt, 21% nickel, 18% chromium, 5% iron, 4% tungsten, 4% molybdenum and 1% titanium. The difference may lie in the remaining 2% composition and the way the springs are tempered.
Regulation is simpler to understand. ETA regulates the standard movement to a tolerance of +/-12 seconds a day, although many watches actually run better. They’re rather fussier with the chronometer models, sharpening those to COSC specs of −4/+6 seconds a day.
A single ETA 2824-2 movement will set a watchmaker back around £225 (about $290), assuming they buy just one.
wornandwound
