Allstar Black 1/4 inch to 3/8 inch Grip Range Large Head Rivet with Aluminum Mandrel (Pack of 250) have a steel mandrel and silver finish on the rivet head. The rivets have a multi-grip style and have a range of up to 1/16 inches to 3/8 inches. They are sold as one set of 250 pieces and are perfect for use around the shop or race track. There are several other popular sizes and colors which are also available and are sold separately..