I am currently prototyping a part for a personal project. My CAD design was contracted out and there are some off the shelf parts that I need to order per the design (springs, screws, etc.).

My designer included two types of springs in the BOM:

  • 3ID x 15mm (possibly 3LD??)
  • 5ID x 5mm

I am not sure what the ID (or LD) naming convention means. Could use some help.

  • $\begingroup$ Welcome to Engineering! This site doesn't accept resource-hunting questions, since such questions are prone to becoming out-dated. I have therefore edited your post to remove a question which fell under that criteria. $\endgroup$
    – Wasabi
    Jun 19 '19 at 1:47
  • $\begingroup$ Request more details from your designer. ID is likely “inner diameter”. That spring notation above is concerning. There should be a part number or more details specified. $\endgroup$
    – GisMofx
    Jun 19 '19 at 2:15
  • $\begingroup$ You need more than two numbers to specify a spring - Looks like you have Inner Diameter and Free Length here, but you need either the Outer Diameter or the Wire Diameter on top of this, or you could end up with completely the wrong stiffness. A BOM should include a part number - ask your designer for this. $\endgroup$ Jun 19 '19 at 9:40

Usually spring's geometry is denoted as : OD* ID* Length. Outside diameter* Inside diameter* Length.


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