Product details:

They were developed in NASCAR and Pro Stock competition, so you know they're tough. They're built on premium 1020AK steel backings and overlaid with Speed-Pro's super-duty H-14 alloy. That's covered with a nickel barrier, followed by a thin lead-tin-copper overplate. However, unlike other performance bearings, there is no flash tin layer on top of that. Speed-Pro's engineers have determined that such a layer can actually move around under high loads--sometimes with undesirable consequences. Depending on the application, these bearings have oil grooves for enhanced lubrication, while maintaining a maximum bearing surface area. They also feature Speed-Pro's exclusive contoured-flange thrust bearing technology for higher thrust-loading capacity.