If you visit the AMD site in the USA (http://products.amd.com/en-us/search/CPU/AMD-FX-Series/) , it clearly shows that the maximum operating temp. for the FX 6300 is 70.5 C, while for 8 core CPUs such as the FX 8350 it is 61 c. In my experience using AMD Overdrive this tallies up perfectly with the readings I get in HWiNFO and HWMonitor in Windows for the CPU core when temps get above 40 odd C. With those monitoring programs showing for instance 50 C. the Thermal Margin figure shows 20 C. (20 + 50=70).
In the Tomshardware article: "An Understanding of Temperature on AMD CPUs and APUs" it clearly states that: "It is perfectly safe to operate in the full envelope of thermal margin. When thermal margin runs out, your CPU/APU will throttle to a lower power state until back in the thermal margin".