those are **** for engine parts or anything that that steel shot can get stick in...then come out when running.... a good charge in the hot tank/jet clean/spray wash will remove everything. I have gotten ballanced assemblys that were full of steel shot...wtf? how can you balance that? and then the steel shot comes out it destroys engine and the unbalance kills the rest... you cant fix stupid. Ive gotten new balanced high performance connecting rods with the steel shot between the bolt heads and rod, and worse some in the threads ,