The Safety Shaft is one of my oldest products and I require putting one in every engine. The full story is outlined in my Conversion Manual, but in short, my Safety Shaft is an up-to-date, precision manufactured component integral to the conversion.
Although he called it a different name, and it had different dimensions, Bernie Pietenpol pioneered the concept of the safety shaft. My piece is an evolution on his concept and has been in every engine I’ve built since 1995. It serves the dual purpose of retaining the crank flange while providing a redundant mount to the prop hub. The Safety Shaft itself is made from aircraft grade 7075 aluminum, is CNC machined. and weighs about 8 ounces.