You could try
www.friebe-luftfahrtbedarf.de in Germany for aircraft quality
parts if you canīt find
other sources in your country.
Nomeclature ist easy, M8 x 30 - 12.9 for example means
M ... Metric standard thread
8..... diameter is 8mm
30...length 30mm
12.9 means 1200N/mmē ultimate tensile strength, and a yield strength of 90%
of UTS.
Michael