I don't have QQ-S-752. It looks like one of those ancient specs superseded long ago. Typically, you need a historic document subscription in IHS to get access to these. I had one at one time because I worked with 727's and DC8's.
If you follow the link below, you will be able to see that QQ-S-752 is 4140 steel. If you need material properties or current AMS spec info, you could look in MMPDS.
thanks for the link, I've never come across that figmat.pdf document before.
IHS.com and all the other standards repositories do not have a lot of the AN-QQ-XX-XXX specifications. If anyone has someplace else to try I'd like to hear about them.