The volcanic creation of the Canadian Shield took place during the Earthâs earliest geologic era, the Precambrian, which includes the earliest 80% of Earthâs existence. The Precambrian era ranges from about 5 billion to 570 million years ago.This process continues today in such places as Hawaii.he volcanic creation of the Canadian Shield took place during the Earthâs earliest geologic era, the Precambrian, which includes the earliest 80% of Earthâs existence. The Precambrian era ranges from about 5 billion to 570 million years ago.
608 STANDARD. The most common bearing size is the â608.â Characterized by an 8mm core, a 22mm outer diameter and a 7mm width, these bearings are the industry standard and match up with nearly every skate wheel out there. NON-STANDARD Of course, there are exceptions to every rule.
What Is a 608 bearing? The most common standardized ball bearing size is the 608 series. The 608 series is the original standard ball bearing. In the 608 series, the ball bearing typically consists of optional closures, inner race, outer race, balls, and ball retainer. It is characterized by an 8mm inner diameter (the bore of the ball bearings), a 22mm outer diameter, and a width of 7mm.