Chinese Type 56 (1956–): Numerous minor tweaks, including lack of milling on the bolt carrier, partially or fully stamped (as opposed to milled) receivers, and differing types of thumb rest on the take down lever. The Chinese continually revised the SKS manufacturing process, so variation can be seen even between two examples from the same factory. All of the Type 56 carbine rifles have been removed from military service, except a few being used for ceremonial purposes and by local Chinese Militias. Type 56 carbines with serial numbers below 9,000,000 have the Russian-style blade-type folding bayonet, while those 9,000,000 and higher have a "spike" type folding bayonet. Some early examples are known as "Sino-Soviet", meaning they were produced by China, but with cooperation from Russian "advisers" who helped regulate the factories and provided the design specifications.