We would have liked to test a few more different types of cores, however, the types of bolts and nails were limited at the local City Mill. More types of cores would have allowed us to rank and compare the different strength among the cores. It would have been nice to have iron bolts of the exact sizes and structures as the Zinc-Steel and Galvanized Metal bolts we had, this would have allowed us to truly examine the difference in the best material possible to the other materials.