During more than 30 years in my small but comfortable shop, I have repaired thousands of crankshafts by welding. One thing I have learned in that time is that when a customer brings a crank to be repaired, you must take note of exactly what type of crankshaft you will be working on.
Many of the aftermarket cranks being used today are very different than the original stock crankshaft. The aftermarket crankshafts are usually made of much better grades of steel, so it is not uncommon to have two cranks that look exactly alike.
But if one is a 5140 grade of steel and the other is a 4340 grade, the price of the 4340 crank may be as much as $200 higher just because of the quality of the steel. Knowing the difference is critical