zx32tt,
Have to disagree here with you. A bolt made from low grade steel can and will eventually snap. Happened to me on my Fuji 50. For some reason I replaced the stock bolt with a cheap one and one day (luckily I was standing behind the motor) the bolt head snapped and the prop came off when the motor was running at half throttle. The prop flew straight for about 50 yards before hitting a pile of dirt. The reason for this failure was simply too much stress for this type of steel.