Chinese O-Ring Material Standard

[PDPumpGuy]

I have been given the following materials from a Chinese vendor for o-ring materials. I think the GB1235 is a pretty common standard in China, but I can't find any cross reference to what they are equal to in the USA.

Does anyone know what these materials are (I think they are Buna-N)?

Is there a web site out there with a good cross reference?

Thanks

 

[Demon3]

I am no expert on o-rings but a Google search for "GB1235 standard" gave some promising links.

http://www.rockseal.net/english.htm

http://www.cjdl8848.com/e1.htm