It's pretty complex, but here I go...
1. Make a Tough Tool Rod Pattern in the Stencil Table out of a Blank Pattern
2. Make a Stone Tough Tool Rod in the Part Builder with the Tough Tool Rod Pattern
3. Put the Stone Tough Tool Rod in the Casting Table which is part of the Smeltery, and pour Aluminium Brass in. That makes the Tough Tool Rod Cast
4. Make 2 Iron Tough Tool Rods in the smeltery with 144 millibuckets of liquid iron, aka 3 ingots, each, which totals to 288 millibuckets which is 6 ingots, using your Tough Tool Rod Cast in the Casting Table
5. In the Crafting Table: 6 leather, 3 on the top and 3 on the bottom. 1 Gold/Aluminium Brass Ingot in the middle, and 2 Iron Tough Tool Rods on the left and right
At least it's easier than making a GraviChestPlate.