Backup Rolls

Nongrooved rolls which stiffen or strengthen work rolls.

Banded Structure

Appearance of a metal showing parallel bands in the direction of rolling or working.

Banding

Inhomogeneous distribution of alloying elements or phases aligned in filaments or plates parallel to the direction of working.

Base Box-General

An agreed upon unit of area used primarily in packaging applications. One common base box for aluminum is 31,360 square inches, originally composed of 112 rectangular sheets each 14 by 20 inches.

Bauxite

The only commercial ore of aluminum, corresponding essentially to the formula Al2O3xH2O.

Beading

Raising a ridge on sheet metal.

Bearing Load

A compressive load supported by a member, usually a tube or collar, along a line where contact is made with a pin, rivet, axle, or shaft.

Bearing Strength

The maximum bearing load at failure divided by the effective bearing area. In a pinned or riveted joint, the iffective area is calculated as the product of the diameter of the hole and the thickness of the bearing member.

Belled Edge

Excessive buildup of material on edge(s) during a rewinding operation. Typical causes include excessive edge burr, turned edge, and "dog bone" shaped cross sectional profiles.

Bend Radius

The inside radius of a bent section.

Bend Test

Various tests which is used to ascertain the toughness and ductility of a metal product, in which the material is bent around its axis and/ or around an outside radius. A complete test might specify such a bend to be both with and against the direction of grain. For testing, samples should be edge filed to remove burrs and any edgewise cracks resulting from slitting or shearing. If a vice is to be employed, then you must line the jaws with some soft metal, to permit a flow of the metal in the piece being tested.

Billet

A solid semi-finished round or square product that has been hot worked by forging, rolling, or extrusion. An iron or steel billet has a minimum width or thickness of 1 1/2 in. and the cross-sectional area varies from 2 1/4 to 36 sq. in. For nonferrous metals, it may also be a casting suitable for finished or semi-finished rolling or for extrusion.

Blank

A piece of metal cut or formed to regular or irregular shape for subsequent processing such as by forming, bending or drawing.

Blister

A defect in metal, on or near the surface, resulting from the expansion of gas in a subsurface zone. Very small blisters are called pinheads or pepper blisters.

Blister, Bond

A raised spot on only one surface of the metal whose origin is between the cladding and core in clad products.

Blister, Coating

A blister in the coating of an alclad or a clad product.

Blister, Core

A raised spot (one or both sides) on rolled metal.

Blowhole

A cavity which was produced during the solidification of metal by evolved gas, which in failing to escape is held in pockets.

Body-Centered

Having the equivalent lattice points at the corners of the unit cell, and at its center; sometimes called centered, or space-centered.

Bond Blister

A blister at the interface between the cladding and core of alclad or clad products.

Bow, Lateral

Deviation from straight of a longitudinal edge.

Bow, Longitudinal

Curvature in the plane of sheet or plate in the rolling direction.

Bow, Transverse

Curvature across the rolling direction of sheet or plate.

Brake

A piece of equipment used for bending sheet; also called a bar folder. If operated manually, it is called a hand brake; if power driven, it is called a press brake.

Brazing

Joining metals by fusion of nonferrous alloys that have melting points above 800 F (425C), but lower than those of the metals being joined. May be accomplished by a torch. Filler metal is ordinarily in rod form in torch brazing; whereas in furnace and dip brazing the work material is first assembled and the filler metal may then be applied as wire, washers, clips, bands, or may be bonded, as in brazing sheet.

Bright Dip

An acid solution into which pieces are dipped in order to obtain a clean, bright surface.

Bright Sheet, One Side Bright Mill Finish (1SBMF)

Sheet having a moderate degree of brightness on one side and a mill finish on the other.

Bright Sheet, Standard One Side Bright Finish (S1SBF)

Sheet having a uniform bright finish on one side and a mill finish on the other.

Bright Sheet, Standard Two Sides Bright Finish (S2SBF)

Sheet having a uniform bright finish on both sides.

Brinell Hardness Test

A common standard method of measuring the hardness of materials. The smooth surface of the metal is subjected to indentation by a hardened steel ball under pressure. The diameter of the indentation, in the material surface, is then measured by a microscope and the hardness value is read from a chart or determined by a prescribed formula.

Bristle Mark

Raised surface about one inch long, crimped wire shaped and oriented in any direction.

Brittle Fracture

Fracture preceded by little or negligible plastic deformation.

Brittleness

The tendency of a metal or material to fracture without undergoing appreciable plastic deformation.

Broaching

Multiple shaving, accomplished by pushing a tool with stepped cutting edges along the piece, particularly through holes.

Broken Edge

Edge containing cracks, splits, or tears.

Broken Surface

A surface having innumerable minute cracks running normal to the direction of working.

Brown & Sharp Gages (B&S)

A standard series of sizes refered to by numbers, in which the diameter of wire or thickness of sheet metal is generally produced and which is used in the manufacture of brass, bronze, copper, copper-base alloys and aluminum. These gage numbers have a definite relationship to each other. In this system, the decimal thickness is reduced by 50% every six gage numbers- while temper is expressed by the number of B&S gage numbers as cold reduced in thickness from previous annealing. For each B&S gage number in thickness reduction, where is assigned a hardness value of 1/4 hard.

Bruise

A greatly enlarged roll mark whose height or depth is very shallow.

Buckle

Bulges and/ or hollows occurring along the length of the metal with the edges remaining otherwise flat.

Buckle, Arbor

Bend, crease, wrinkle, or departure from flat, occurring perpendicular to the slit edge of a coil and which are repetitive in nature, with severity decreasing as the distance increases in the coil from the original source. Normally, it is found on the ID of a coil but can appear on the coil OD as a result of a prior winding operation.

Buckle, Center

Undulation (wavy region) in the center of the metal.

Buckle, Edge

Undulation (wavy region) along the edge(s) of the metal.

Buckle, Oil Can / Trapped

Undulation (wavy region) which is smaller sized and often circular in shape.

Buckle, Quarter

Undulation (wavy region) which occur approximately at both quarter points across the width.

Buffing

A mechanical finishing operation in which fine abrasives are applied to a metal surface by rotating fabric wheels for the purpose of developing a lustrous finish.

Buff Streak

A dull continuous streak caused by smudge buildup on a buff used at shearing or other operations.

Burnish Streak

A bright region on the sheet caused by excessive roll surface wear.

Burnishing

Smoothing surfaces through friction between the material and material such as hardened metal media.

Burred Edge

A thin turned down edge on sheet or foil resulting from shearing.

Butt Welding

Joining two edges or ends by placing one against the other and welding them.