Timex 1854 military style :)
I have never owned a watch with anything other than springpins, and they have never broken yet lol.
Screws are almost always going to be stronger, assuming they're about the same diameter as the spring bars. Spring bars are hollow, thin-walled tubes of metal that attach to the case with two little tiny pips in relatively shallow holes. The screws are solid and go all the way through the lugs. More metal = more strength.
But then, you almost never have a choice on a given watch. Spring bars will just rattle around in the larger screw holes, and you can't put screws in a case that normally takes spring bars unless you drill the lugs all the way through and tap them.
I think screws are always going to have an edge when it comes to strength.
A man with one watch knows what time it is..
A man with two watches is never quite sure.
Most screw bars are hollow, in engineering terms tubular is always stronger than solid I think the only reason why the tube and screws would be a little stronger is because it is fed through the lugs, so really the lugs are the the only reason why it would take more pressure to break/bend, not because of the bar but the lugs as the anchor point.
Just my opinion.
Or are you talking about the kind that's a tube in the middle and then a short screw that goes into each end? Those I can see as being only marginally stronger than springbars for the reason you stated.
Are there any stats for which type has a higher failure rate? I still like the screwbar set-up but I fear stripping the threads at some point, or shearing a screw. I guess it boils down to personal preference. Having said that, I would really like to find some stats on the failure rate for screws vs springs.
Life is tough. It's tougher if you're stupid.
The thing is a hollow tube CAN be stronger from the standpoint of weight in torsion. Torsional stress for a solid or hollow rod/tube is:
Where J is the polar moment of intertia for a tube is:
J= (PI/64)*((DO^4) - (DI^4))
For a rod it is:
Since most of the stress is in the outer fibers, removing the inner part of the rod, to make a tube and increasing the outer diameter gives a hollow tube that is stronger in torsion than the rod. It will however, have a larger outside diameter.
The same is true in bending.
There are more things at stake here than just the bending and torsional stress and deflection. Using welded or seamless tubing can affect the laod capacity of the tube, and there is always the isssue of buckling under load.
Sometimes people draw vast conclusions from half-vast data.
The bottom line is that a hollow tube CAN be stronger, by weight, but not by size, than a solid rod of the same material BLAH BLAH BLAH .
Last edited by SHANE 1000; January 25th, 2009 at 06:21.
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf"
There are currently 1 users browsing this thread. (0 members and 1 guests)