The hub on my Q series have steel thread inserts on the back (engine side of the hub). The washers are actually a pair that work together, the side that mates together have little jagged like edges that mate together. The side against the hub cover and the bolt side have ridges. A really good video showing probably the most accurate way to set the pitch.

I humbly disagree with your comment. Canadian Airboat ice hulls are engineered with marine grade aluminum and have reinforcing down the sides, transom, and gunnels, inside and outside specifically to deal with extreme sidewall pressure of "Railroading". Our hulls will withstand more pressure than a fiberglass airboat hull while at same time being light weight in comparison to a fiberglass hull of a comparable strength rating. We have not had a sidewall failure as a result of railroading conditions on our TP1332 ice airboats in the history of our company. Canadian Airboats and their many oil industry clients take advantage of the power to weight and strength advantage of aluminum and in fact have done extensive testing in northern Canada specific to the severest of railroading conditions in spring, winter and fall, for decades. Our airboats have been field tested and passed with excellent success. By the way, the term "Railroading" was introduced to the airboat industry originally by Canadian Airboats in our C.A.S.S. Ice Airboat Safety Training Program and on our website. Stay safe and if you are ever in Vernon BC, come see us. You are welcome any time.