An assortment of weld studs from The Hillman Group. These weld studs feature three projections under the head. Also known as ring weld studs, these bottom projection studs are screws that form a tight seal to prevent the leakage of water, oil, gas, or other amorphous materials. The three projections provide a strong, durable weld joint. Included parts come in 5/16"-18 & 5/16"-24 coarse and fine thread variants. Parts range from 1/2" to 2" in length. Full assortments of #34686 contain eleven (11) refills comprised of Hillman item numbers #34687 - #34697.