I would not expect that to wear it out.However, leaving it half open, with maximum strain on the spring, has been seen to weaken the spring and is used as a way to weaken springs in folding knives, if they are too strong.
Thanks knights, much appreciated So you reckon the only thing that would wear out the back spring is half extended tools? That would mean that in theory, you could store a SAK with all implements extended and it wouldn't be any worse for wear. Weird.
The actual answer depends on many factors everybody above is ignoring. Tang styles and era of production have lots to do with how bad it is to leave the tool open or whatever various positions in between. At the extreme, some are even better off stored open. 111mm slide locks leave the backspring in a lower stored energy state than closed. Some tangs like inline Phillips and 90° caplifters are about the same in the 90° positions. Highest spring stress is closer to the 45° and 135° positions. I would never store a knife from about 1970 and earlier with tools in part open states. Also wouldn’t recommend it for ‘80s. ‘50s and earlier it’s a total sin and doing this is almost asking for a spring to break. But I wouldn’t hesitate to do so for knives from the ‘90s and later. Factors like surface polishing and tang and spring seat designs and interactions all play a part in this issue or lack thereof over time. Essentially, new knives have lots of details that keep the backspring out of any real danger of creep, bending or fracture. They operate well within the lower elastic range of the steel they use. Please trust that Victorinox actually made significant improvements over the years, and that we all benefit from these developments. So enjoy and display your modern knives as you please. But be nice to your older friends.
Many thanks for your knowledgeable answer, Kamakiri I am sure I am not the only one to appreciate your explanation very much
The actual answer depends on many factors everybody above is ignoring.
Apologies from all above.We were trying to provide simple quick answers, that do not seem to be up to the standard required.
Please trust that Victorinox actually made significant improvements over the years, and that we all benefit from these developments.
100% this. I have only my anecdotal evidence with comparison of older 108 GAK and new 111 Forester, but there was very tangible difference in feeling how the implements opened/closed - in the end I sold the GAK and kept only the Forester. It just felt so much better in use.And thanks Kamakiri for you input - very informative.
Fellow knights, I wonder if any of you know whether leaving an implement extended continuously wears out the back spring? I would think not as Vic themselves are selling SAKs with extended implements (=large blades in its Damast collection), but I am not certain and would be curious to know. Thanks for any input!Cheers,Simon