Chuma cha alloy 1.251 +chuma cha alloy +O1 (2) 1.251 +alloy chuma +O1 1.2379 +alloy chuma +D2 1.7035 +alloy chuma +5140 D2+Titanium nitride 1.7035 +alloy chuma +5140 1.7035 chuma cha pua+SUS304 1.7225 +alloy chuma +4140 1.7225 +alloy chuma +4140 440c+DLC alloy chuma 1.2379 +alloy chuma +D2 440c+DLC alloy chuma