Metal Rings
Roll formed metal rings are metals that have been roll-formed into circular patterns. They are often used in low-impact applications including clamping, sealing, joining or trimming items such as drums and lids, street signals or mirrors. Seamless rolled rings, or forged rolled rings are forged from solid blocks of metal and offer superior tensile strength and structure for high-impact applications.
Roll formed metal rings begin as sheet metal or wire and are then cold roll-formed by a series of stations, being bent a little more at each one. After they are rolled, they may be cut to their appropriate length. Rolled rings are not joined, however; this must be done separately through welding or notching, and rings are often left open if seaming is not necessary. For this reason, the structural strength of roll formed metal rings is very low and they are used mainly in trim, sealing and finishing applications. Seamless forged metal rings are fabricated from solid round metal blocks which are heated to low or high forging temperatures, pounded and flattened, punched through the center to create a "donut" shape, then pounded and squeeze-rolled through forging calenders to the appropriate thickness and diameter. Since forged rings are made from circular shapes, less material waste is produced and the product is a seamless ring without the stress points of a seamed roll formed ring.
Metal rings may be made into a number of different shapes, most common of which are circular, oval, square, or rectangular. A number of different metals and coatings are used to fabricate metal rings to meet specifications for chemical, oil and gas companies, as well as for various aerospace and military applications; rings may be roll formed from brass, steel, aluminum, copper, brass, zinc and others. Roll formed rings are more commonly plated or painted to improve corrosion resistance and/or aesthetic appeal. Forged seamless rings are more often treated with simple protective coatings in order to endure tougher conditions in applications such as bearing housings, aluminum automobile wheels, rail train car wheels and large-engine turbines.