Eibach Springs Being made
I was looking on YouTube for some good lectures on mechanics of materials and I stumbled upon this gem. This video gave me a significantly higher respect for the spring industry in less than ten minutes.   Order their own alloys to spec. Check.  Cold/hot form springs up to 55 mm. Check  In house heat treatment and strain hardening. Check  In house testing and quality. Check  In house paint and coating. Check.   Awesome ties to F1 and Rally racing. Check!