Mechanical Spring Representation 1

[Eltron]

I'm running up against a wall in specifying the standards for information that needs to be included on an engineering drawing of a spring. So I thought I'd ask the experts. I have done a search and checked the FAQs, but I haven't found anything yet. ANSI Y14.13M used to be the standard, but it was rescinded. Is it MIL STD 29A? Surely I'm missing something obvious.

Dan

http://www.eltronresearch.com

Dan's Blog

 

[desertfox]

hi
Check this link and go to page 4 it shows you how and what to specify for a compression spring:-

http://leespring.biz/downloads/uk/leespring_engguide.pdf

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[israelkk]

I am not familiar with a standard for specifying a spring. But MIL-STD-29A gives what is necessary to include in the drawing. However, remember to ask only for what is necessary and give the spring manufacturer the maximum allowed freedom to "play" with free length and outside/inside diameter, meaning the largest tolerances you can allow. However, wire diameter which dictates the spring wire strength should be strictly defined. Remember, that spring is coiled and not machined therefore, allow a +/-10% tolerance for the spring force at a specified compressed length/s.

 

[Eltron]

Thanks, fellas. That's what I thought. I'll just cherry pick the pertinent information from old standards for what I want to see on drawings. Why did ANSI drop the spring standard, I wonder?

Dan

http://www.eltronresearch.com

Dan's Blog

 

[desertfox]

Hi Eltron

You're very welcome.

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[tbuelna]

What information you include will depend on the type of drawing format and how the spring is procured. For example, a spring manufactured to your specific requirements by a qualified/approved vendor would require a source control drawing (SCD), which can be quite detailed. A spring that can be purchased as is from a list of approved sources would require a vendor item control drawing. A spring that is purchased as is from a vendor and then modified in some way for your application would require an altered item drawing.

If you intend to purchase a custom spring using a SCD, work with your vendor to ensure they are comfortable with everything specified on your drawing before releasing it. But also make sure your final SCD explicitly defines every detail so there is no confusion over the finished product your vendor needs to deliver.