Clarify Dimensions on Spec

[HaroldL]

While inserting a ISO-10511 prevailing torque nut from the library, I found that it wasn't quite up to spec. I thought I'd take a shot at modeling up a part to replace the one in the library but am stymied by some of the dimensions on the spec because it is unclear what they are referencing.

I can work out the detail for the locking insert and retainer but can someone that is more familiar with metric fasteners help clarify to what the highlighted dimensions on the following image refer to? Any help would be appreciated.

 

[Stu3d]

Here are some clues to help you search what they actually mean.
da is turning diameter shrinkage
dw is the diameter of the bearing face or contact surface diameter
mw is wrenching height Edit, found this Wrenching Height, J. Wrenching height is a distance measured from the bearing surface up the side of the head at the corners. The width across corners shall be within the specified limits for minimum wrenching height.

ISO 10511 - Prevailing torque type hexagon thin nuts with nonmetallic insert

 

[HaroldL]

Thanks Stu. I had looked at a few supplier web sites but none had the information in your link. Okay, so dw is likely derived from and related to the 15 to 30 degree chamfer and mw, (and m' on the your linked spec) is Wrenching Height, J, but what is turning diameter shrinkage? Is that related to the diameter of the non-metallic locking ring insert? After a bit of searching I only see it on other ISO lock nut specs.

 

[DavidJ]

Looks like diameter of the chamfer under the nut....

 

[HaroldL]

Well this is turning into a nightmare. Checking the rest of the prevailing torque lock nuts in the library it appears that they are all modeled in error - they are missing the prevailing torque element.
@Max could someone double check these, just to make sure I'm not seeing things. And, if there is an issue, what does that mean for the new library that is planned.

Here's what I have in my folder:


Here's what the models should preview like:



And here's a spec drawing. It's easy to see how the prevailing torque feature could be missed if this is the image/spec that was used to model the lock nuts.