Grades of ETA movements

[andrema]

I saw this quick reference at another forum and wanted to pass it along:

Standard and Elaboré:
Mainspring - Nivaflex NO
Shock protection - Etachocs
Pallet stones - Polyrubies, Epilame-coated
Balance - Nickel gilt
Balance staff - Epilame coated
Collet - Nivatronic
Hairspring - Nivarox 2
Hairspring heat treatment - Etastable



Top and Chronometre:
Mainspring - NivaflexNM
Shock protection - Incabloc
Pallet stones - Red rubies, Epilame-coated
Balance - Glucydur gilt
Balance staff - Epilame coated
Collet - Nivatronic
Hairspring - Anachron
Hairspring heat treatment - Etastable



The performance differences are the big differences between the various grades: ("The limit values are subject to interpretation: 95% of the pieces delivered in a lot must be within the specified limits.")



Standard:
2 positions (CH, 6H)
daily rate: +/-12 sec/day
Maximum positional variation: 30 sec
Isochronism (between 0 and 24 hours): +/- 20 sec


Elaboré:
3 positions (CH, 6H, 9H)
daily rate: +/-7 sec/day
Maximum positional variation: 20 sec
Isochronism (between 0 and 24 hours): +/- 15 sec


Top:
5 positions (CH, FH, 6H, 9H, 3H)
daily rate: +/-4 sec/day
Maximum positional variation: 15 sec
Isochronism (between 0 and 24 hours): +/- 10 sec


Chronometre:
As per COSC specifications, which as far as most owners will notice, isn't much different from Top grade.