If you are doing your brakes make sure the pins are the correct ones for the caliper and not just any old pin as they are usually an alloy metal and much stronger than mild steel .
The pins for my capri are hard to get, having a spacer in the m16 callipers and being slightly longer.
The simple fix was to use landrover split pins, which are cheaper, although its best to replace them instead of reusing, buth then the pins are usually shot anyway and are best replaced.