Joining I: Welding, Mech. Fastening

welding

permanent joining of two metals

fusion welding

metals being joined are melted at the point where welding occurs, and no pressure is involved

bead welds

[Fusion Weld] made directly onto a flat surface and therefore require no edge preparation

groove welds

[Fusion Weld] when full-thickness strength is desired on thicker material

fillet welds

[Fusion Weld] used for tee, lap, and corner joints and require no special edge preparation

plug welds

[Fusion Weld] attach one part on top of another and are often used to replace rivets or bolts

oxyfuel-gas welding

[Welding] group of welding processes that use the flame produced by the combustion of a fuel gas and oxygen as the source of heat

1:1

[OFW] oxygen-fuel gas ratio is between __ and 1.15:1

1.15:1

[OFW] oxygen-fuel gas ratio is between 1:1 and __

neutral

[OFW] most welding is done with a __ flame

oxidizing flame

[OFW] higher oxygen-fuel gas ratio, such as 1.5:1; used when welding copper and copper alloys but are generally considered harmful when welding steel

carburizing or reducing flame

[OFW] produced by excess fuel; used in welding Monel (a nickel–copper alloy), high-carbon steels

oxyfuel-gas cutting

[OFW] commonly called flame cutting, is the most common thermal cutting process

acetylene

[OFC] most common fuel used in oxyfuel-gas cutting

arc welding

[Welding] concentrated heat source from the electric arc between two electrodes

shielded-metal arc welding

[Arc Welding] called stick welding or covered-electrode welding, is among the most widely used welding processes because of its versatility and because it requires only low-cost equipment

resistance welding

[Welding] both heat and pressure are utilized in producing coalescence; heat is obtained from the resistance of the workpieces

resistance spot welding

[Resistance Welding] simplest; water-cooled electrodes, having reduced areas at the tips, are used to produce welds that usually are from 1/16- to ½-inch in diameter

resistance seam welding

[Resistance Welding] made by a series of overlapping spot welds

resistance projection welding

[Resistance Welding] a dimple is embossed into one of the workpieces at the location where a weld is desired; heating is concentrated where the weld is desired

mechanical fastening

widely used, cost-effective means of joining; utilize a variety of fasteners including nuts and bolts, screws and rivets, or mechanical interlocks to assemble materials without heating

integral fasteners

[Mechanical Fastening] formed areas of a component that interfere or interlock with other components of the assembly

discrete fasteners

[Mechanical Fastening] separate pieces whose function is to join the primary components (bolts and nuts, etc.)

shrink and expansion fits

[Mechanical Fastening] dimensional change is introduced to one or both of the components by heating or cooling

press fits

[Mechanical Fastening] similar to shrink and expansion fits, but the results are obtained through mechanical force instead of differential temperatures