What do 抓铁有痕 and 踏石留印 mean?
There is a Baidu Baike article about it:


  常作褒义词应用，与“蜻蜓点水”一词互为反义。一般是用以形容人的工作扎实，不管干什么工作都能留下自己业绩。应用中常与“踏石留印”连用，如：要让“踏石留印，抓铁有痕”成为我们推进各项工作的“规定动作”，而且要成为一种“工作常态”，使实效见诸“终端”。形容做事情不达目标不罢休,有坚持到底,做就要做好的精神。


It is a figurative way of saying a person would leave solid results in his work.

"He can even leave footmarks when he is walking on a stone"