i got them from my dads work, but any engineering type place will sell them. I put in an old bolt by mistake when putting them back together and it was only a couple threads short, you could maybe use them but people on here said to use longer ones, so i did. when asking for the new bolts remember and ask for high tensile ones. cheap bolts might snap or bend, remember these bolts basically take all the weight of your car stopping when you hit the brakes so id make sure they are good quality