someone educate me about "jeweled" clocks/watches

S

shadowfax

Joined
Jan 29, 2001
Messages
172
I always thought an 8 jewel or whatever quartz watch had 8 diamonds on the face. Then today someone gave me a wall clock as a present. It's made out of a sawblade, so according to my previous assumption it shouldn't even have a jewel rating, but on the back it says "0 jewel quartz," so now I'm thinking the jewel has something to do with the mechanism itself. Anyone wanna clear that up for me?
 
I am no expert, but recall that the number of jewels in the mechanism of a watch referred to the jewels used as bearings in the mechanism. I believe they used to use synthetic rubies (perhaps real ones at first).

Walt
 
Walt is correct. Small bits of semi-precious stones (often rubies, either natural or manmade), are used to support and allow for the smooth rotation of certain key elements of the watch mechanism. I say "key" elements because generally speaking the jewels are reserved for use with only those pieces which are under the most direct strain from the watch's mainspring (or motor, in the case of quartz watches). A standard rule of thumb is that the more jewels used, the better the mechanism. There is, however, a point of diminishing return that is quickly reached in this regard. A good quartz movement doesn't really require more that 7 to 9 jewels, while a really good mechanical movement will feature somewhere around 21 to 25 jewels. Multi-register chronographs are another story altogether, however, and can have many more.

------------------
Semper Fi

-Bill
 
The main reason to put semiprecious stones in watch movements is to reduce friction. It's save to say that the harder the surface of moving parts is the less friction they have, everything else being equal. The rubies in the movements are the bearings at the end of axles for fast moving parts like the escapement, etc. and make the watch more accurate.

Another reason is to reduce wear. Hard surfaces last longer than soft ones.

Rubies are used because they are far easier to manufacture than diamonds. The ideal combination in terms of wear and friction would be a diamond bearing with a diamond axle.

For some nice pictures go here. The bottom two show clearly what I’m talking about.

http://www.timezone.com/WatchSchool/The_Horologium/Patek240/patek240.shtml
 
<font face="Verdana, Arial" size="2">For some nice pictures go here. The bottom two show clearly what I’m talking about.</font>
Click to expand...
Also lots of examples of the other kind of jeweling.
 
You must log in or register to reply here.
Back
Top