Talk:Axes/@comment-71.82.220.56-20171118201805/@comment-2601:404:C200:4000:CDD4:E7A3:1033:1495-20171130011307

If you continue to play and save up money you can purchase higher tiers of materials. It seems the best way to go about reaching a new tier is buy 3 ingots, make a pickaxe, then head for the mines and Mine out any veins that are the same material as your new pickaxe.

If there aren't any veins left and you want to mine more though, you can either mine out other veins and let them respawn the next day or save and reload in order to re-randomize the cave.