Lot of 7 JP Carlton SP7015 Stump Grinder Wheel Center Bolts: 1-8 X 8 Grade 8 Domestic. These are domestic steel from the same supplier that JP Carlton uses. The imported bolts quickly break but these last quite a bit longer. This is the center bolt that bolts the entire front dual wheel and tire to the center of the inner front wheel and tire. I case I forgot to get a picture of the head it had the triangle symbol of domestic steel manufacture.