55 gallon drum

A drum is a cylindrical container used for shipping bulk cargo. Drums can be made of steel, dense paperboard (commonly called a fiber drum), or plastics, and are generally used for the transportation and storage of liquids and powders. Drums are often certified for shipment of dangerous goods. Shipped goods must be matched with the make of drum necessary to comply with applicable regulations. Drums are also called barrels in common usage.

It is common to hear a drum referred to as a barrel and the two terms are used nearly interchangeably. Many drums have a common nominal volume of 208 litres (55 US gal; 46 imp gal) and nominally measure just under 880 millimetres (35 in) tall with a diameter just under 610 millimetres (24 in) and differ by holding about thirteen gallons more than a barrel of crude oil. In the United States, 25-US-gallon (95 l; 21 imp gal) drums are also in common use and have the same height. This allows easy stacking of mixed pallets. Barrels can be constructed of plastic, laminated paperboard or steel.

The two common sub-types of drums are the open top and the welded top (with 2-inch (51 mm) NPS bung holes). The latter are almost universally called "barrels" in preference to drums in the United States. They cannot efficaciously either dispense or be filled with powdered goods, though they might store them very well, so are not used for such goods, being reserved for liquids transport and storage. Plastic drums are manufactured using injection blow moulding technology and have either a separate lid (similar to those on fiber drums) or a welded type top with the bung holes molded in. Metal drums are manufactured with cold-rolled steel sheets, welded themselves into long pipe-like sections then forged on a stamping press into drum bodies. A rolled seam is then made for the drum bottom, or bottom and top both.

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