- 316 stainless steel gaff hook - Ideal for building fishing gaffs - Large 9mm diameter, flattened for strength - 3 1/2" hook gap. Want to land that big fish with a reliable hook? Yellowfin Gaff Co 316 stainless steel gaff hooks are super strong and durable with a flattened radius to prevent bending. Most gaff hooks on the market are duratin or carbon steel, but Yellowfin Gaff Co hooks are stainless which is corrosion resistant. So, go on and build yourself that gaff! A better hook, means a better gaff!