This is a sprocket for a long wall coal mine pic shaft we repaired. The plate we repaired it with was T1 steel also called a209. Preheat was 350 f and post heat was 350 f for 30 minutes. We used Haas ec2000 and Bullard 64” cutmaster for machining operations. I will also post video. Replacement cost was $15,000.00 and there were no replacement parts available for a month. We repaired it in two days and saved them a bundle.