This is most likely a DIN 985 lock nut. This is a thin version of a DIN 982 which is a standard nylon insert lock nut. The height for an M14 is also 14mm. They are most likely going to be zinc plated. Cad is very difficult to get due to EPA regulations. Check this link.
http://mdmetric.com/fastindx/ud18_25.pdf
Maryland Metrics is an excellent source for all things metric. Check page 3 of the pdf. I think this is what you need. Looks like about 40 bucks for 100. This is not a typical animal that you are going to be able to buy 4 of. I hope this helps.
