{
  "type": "railcraft:rolling",
  "key": 
  {
    "a": {"item": "extendedcrafting:black_iron_ingot"},
	"s": {"item": "extendedcrafting:black_iron_ingot"}
  },
  "pattern": 
  [
    "as"
  ],
  "processTime": 400,
  "result": {
    "item": "extendedcrafting:black_iron_slate"
  }
}