5 ms·

Also: Lock Washers Don't Work https://news.ycombinator.com/item?id=23584078 https://news.ycombinator.com/item?id=23584078

by mhb 4y ago

walterbell 4y ago
Thanks, we need more DIY methods for quantitative evaluation of fasteners and joints, e.g. replication of this deck screw strength test, https://www.youtube.com/watch?v=eikOUFoIZ-Y https://www.youtube.com/watch?v=eikOUFoIZ-Y https://www.boltscience.com/pages/aboutus.htm https://www.boltscience.com/pages/aboutus.htm > Bolt Science was founded in 1992 with the intention of becoming the recognised worldwide quality provider of independent technical expertise in bolted joint technology. Our clients include many of the major engineering organizations of the world. We provide analytical, testing, and technical problem solving services. We can help you understand the issues regarding the structural integrity of bolted joints and provide engineering solutions based upon our considerable experience in this field.
- willyt 4y ago
  The spax screws have all the information given in this video available on their website because they are a German product and EU law (mostly) requires a data sheet for construction products called a ‘Declaration of conformance’. I’m not sure about the other ones.
  - walterbell 4y ago
    Good to know. Spax screws sold in the US, e.g. at Home Depot, are labelled "Made in USA", https://www.fastenerandfixing.com/insight/spax-quality-made-in-germany/ https://www.fastenerandfixing.com/insight/spax-quality-made-...
throwaway0a5e 4y ago
If I was ever hiring for that kind of engineer repeating this drivel would get ones resume on the fast track to the circular filing cabinet because it indicates an inability to think critically about use cases outside of the box for whatever your definition of box is. People have been mindlessly repeating that "split washers don't work" thing for decades but they're still around. Why? They're helpful for certain combinations of torque applied (low for the fastener size) and vibration (low but not none) that don't tend to apply in the high performance engineering that the internet fetishizes. If they were truly wasted money you wouldn't see them continuing to be used in many structural and consumer applications.
- mhb 4y ago
  Unsurprisingly, snark is not as compelling as testing and NASA's views[1]. [1] Page 9: https://ntrs.nasa.gov/citations/19900009424 https://ntrs.nasa.gov/citations/19900009424
  - throwaway0a5e 4y ago
    This is exactly the kind of know-it-all behavior I am complaining about. It is beyond a condemnation that a professional such has yourself has not developed a sense for "authority X recommends Y but everybody is doing Z, there's probably a reason for that". Split lock washers persist because they are a cheap way to get a decent amount of preload into a bolted joint without torquing the bolt very much relative to typical torque values for fasteners of that size. For highly price sensitive widgets where the nature of the joint means it flex/vibrate too much for "nothing" to not be a acceptable solutions split lock washer is often the cheapest acceptable solution. I understand why NASA says "no locking value". That's a fine rule of thumb for what they do. But they're not making value priced widgets. Having a fastener maintain preload has "locking" value in many practical real world applications.
    - mhb 4y ago
      It could be that you're right, but presenting as evidence that everyone is doing a thing is hardly compelling. Everyone is wearing cloth masks. Everyone is "investing" in crypto. See why "everybody is doing Z" might not be the greatest heuristic?
    - mhb 4y ago
      Let's do something crazy and look at what actually happens with a vibrated split washer[1]. Maybe you can explain how this demonstration differs from the situations in which you are asserting the split lock washers are effective. Is this hardware not crappy enough to be used in the "value priced widgets" where the washers work? [1] https://www.boltscience.com/pages/helicalspringwashers.htm https://www.boltscience.com/pages/helicalspringwashers.htm
    - mlyle 4y ago

Also: Lock Washers Don't Work https://news.ycombinator.com/item?id=23584078 https://news.ycombinator.com/item?id=23584078

by mhb 4y ago

Also: Lock Washers Don't Work https://news.ycombinator.com/item?id=23584078 https://news.ycombinator.com/item?id=23584078

walterbell 4y ago

Thanks, we need more DIY methods for quantitative evaluation of fasteners and joints, e.g. replication of this deck screw strength test, https://www.youtube.com/watch?v=eikOUFoIZ-Y https://www.youtube.com/watch?v=eikOUFoIZ-Y https://www.boltscience.com/pages/aboutus.htm https://www.boltscience.com/pages/aboutus.htm > Bolt Science was founded in 1992 with the intention of becoming the recognised worldwide quality provider of independent technical expertise in bolted joint technology. Our clients include many of the major engineering organizations of the world. We provide analytical, testing, and technical problem solving services. We can help you understand the issues regarding the structural integrity of bolted joints and provide engineering solutions based upon our considerable experience in this field.

willyt 4y ago
The spax screws have all the information given in this video available on their website because they are a German product and EU law (mostly) requires a data sheet for construction products called a ‘Declaration of conformance’. I’m not sure about the other ones.
- walterbell 4y ago
  Good to know. Spax screws sold in the US, e.g. at Home Depot, are labelled "Made in USA", https://www.fastenerandfixing.com/insight/spax-quality-made-in-germany/ https://www.fastenerandfixing.com/insight/spax-quality-made-...

throwaway0a5e 4y ago

If I was ever hiring for that kind of engineer repeating this drivel would get ones resume on the fast track to the circular filing cabinet because it indicates an inability to think critically about use cases outside of the box for whatever your definition of box is. People have been mindlessly repeating that "split washers don't work" thing for decades but they're still around. Why? They're helpful for certain combinations of torque applied (low for the fastener size) and vibration (low but not none) that don't tend to apply in the high performance engineering that the internet fetishizes. If they were truly wasted money you wouldn't see them continuing to be used in many structural and consumer applications.

mhb 4y ago
Unsurprisingly, snark is not as compelling as testing and NASA's views[1]. [1] Page 9: https://ntrs.nasa.gov/citations/19900009424 https://ntrs.nasa.gov/citations/19900009424
- throwaway0a5e 4y ago
  This is exactly the kind of know-it-all behavior I am complaining about. It is beyond a condemnation that a professional such has yourself has not developed a sense for "authority X recommends Y but everybody is doing Z, there's probably a reason for that". Split lock washers persist because they are a cheap way to get a decent amount of preload into a bolted joint without torquing the bolt very much relative to typical torque values for fasteners of that size. For highly price sensitive widgets where the nature of the joint means it flex/vibrate too much for "nothing" to not be a acceptable solutions split lock washer is often the cheapest acceptable solution. I understand why NASA says "no locking value". That's a fine rule of thumb for what they do. But they're not making value priced widgets. Having a fastener maintain preload has "locking" value in many practical real world applications.
  - mhb 4y ago
    It could be that you're right, but presenting as evidence that everyone is doing a thing is hardly compelling. Everyone is wearing cloth masks. Everyone is "investing" in crypto. See why "everybody is doing Z" might not be the greatest heuristic?
  - mhb 4y ago
    Let's do something crazy and look at what actually happens with a vibrated split washer[1]. Maybe you can explain how this demonstration differs from the situations in which you are asserting the split lock washers are effective. Is this hardware not crappy enough to be used in the "value priced widgets" where the washers work? [1] https://www.boltscience.com/pages/helicalspringwashers.htm https://www.boltscience.com/pages/helicalspringwashers.htm
  - mlyle 4y ago