Chapter 5, Section E
The pins are constructed of all wood, a wooden core with a plastic covering, or a synthetic substance, usually some form of plastic. The pin most commonly used has a laminated wooden form covered with a nylon sleeve and plastic coated. It is 15 inches high and approximately 4.76 inches in diameter, with the shape of the pin being graduated in various degrees, and with certain measurements being called for at different heights on the pin
The USBC equipment specification manual gives complete details.
Pins may weigh as little as 3 lbs,2oz each, or as much as 3 lbs 10oz each. The pins used may not vary more than 4 ounces in a set of 10. You could not have both limits in the same set. The heaviest pin that could be used with 3lb 2oz would be 3lb 6oz The variance allowed is to prevent unusual pinfall and leaves.