Its really all about the threads in the aluminum blocks( or other components) for many years aircraft was where alum was used to save weight and components had helicoils installed from the intial build-----wasn't used as a repair as is commonly thought-------altho the use of heli coils as an excellent repair did develope over years.

Today the use of torque to yield and throw away after on use is a process to protect the bigger, more complicated , more expensive parts and throwing away used bolts is cheaper than repairing pulled out threads and the results of that-blown gaskets, leaks, etc, etc