How to measure curved spring bars?

[sierra11b]

Entertaining the idea of servicing this one sometime this year:

viewtopic.php?t=77675

According to my crap calipers, lug with is 18mm on the watch head, but the original roached curved spring bars are 21mm tip-to-tip when fully extended.

If I purchase 18mm curved bars are they 21mm? Never had the opportunity to order curved bars.

[tmw]

I always order the same size. So it 20mm I order 20mm curved spring bars and never had an issue.

I usually just get from Amazon or eBay.

[Wario406]

I always order the same size. So it 20mm I order 20mm curved spring bars and never had an issue.

I usually just get from Amazon or eBay.

^^^^^^ what he said ^^^^^^^

[toxicavenger]

Typically you measure from the spring bar flange (shoulder) flange for the length. I usually recommend a 19mm spring bar for a 18mm lug watch. That way you have full engagement into the lugs and the flanges rest against the case.

[Goyoneuff]

18mm will be for 18mm lugs, etc. The curvature is taken into consideration. I have used twice, on a Breatling and on an old Zodiac. Cheers, G

[maniloveturtles98]

U can use a caliper to check how wide and long the spring bars are at widest and narrowest points. U might also need to find how round the curve is. checkt the lug width of your watch too it affects the size u need.
If u have an old spring bar somwhere, making a new one like it could help. U can use a string or wire too,just lay it next to the old bar, then measure it. Common sizes are around 21mm and 22mm. This worked on my old iwc. Good luck partner