On our CodyCross answers based website we have the solution for Hard metal used in ball-point pen tips, symbol Os. CodyCross game includes different missions and events which update daily so you can earn tokens that are mostly needed to help with answers for challenging clues. Now let's focus on the answer you need for Hard metal used in ball-point pen tips, symbol Os by scrolling down which is part of CodyCross Periodic Table Group Puzzle 11.