Kitchenaid Artisan 8 piece steam boiler bolt kit. If you are replacing any part of the steam boiler assembly, you should seriously consider replacing the bolts also.
The original bolts can be very difficult to remove and if care is not taken they can break. Due to the heat in the steam boiler the bolts oxidise and become weakened. We usually spray the bolts with WD40 first and allow time for this to penetrate before attempting to remove them.