SOLAS Sheet Metalworking key terms

A fixed reference point, line, or surface from which measurements are taken when marking out or machining a workpiece, ensuring all dimensions relate to one consistent origin.

The process of transferring dimensions from a drawing onto sheet metal using scribers, dividers, and punches before cutting or forming begins.

A chain-dotted line on a technical drawing indicating an axis of symmetry or the centre of a hole, bend, or cylindrical feature.

A drawing method showing a three-dimensional object as separate front, plan, and side views arranged at right angles, with hidden detail shown as dashed lines.

A drawing in which all features are reduced or enlarged by a stated ratio, such as 1:5, so real dimensions can be read directly from the sheet.

An intentional extra amount added to a dimension to cover bending, clearance, or finishing needs, such as bend allowance added to a developed pattern length.

The length of material consumed by a bend, calculated from the neutral axis arc so that the flat pattern is the correct size after forming.

The distance from the bend line to the outside mould line, subtracted when calculating flat pattern dimensions for a formed part.

The theoretical layer within a bent sheet that neither stretches nor compresses, used as the reference arc for calculating bend allowance.

The partial elastic recovery of metal after a bending force is removed, causing the finished angle to open out slightly beyond the set angle.

The line on a developed pattern where a flat sheet is to be folded to form an edge, flange, or corner of the finished component.

The process of laying out a true flat pattern of a three-dimensional sheet metal component, including all bend lines and cut-outs, before fabrication.

A development technique that divides a curved or oblique surface into a series of triangles to determine the true lengths of edges on the flat pattern.

The actual size of a line or edge as it appears on the object, found by projection when it is foreshortened in a drawing view.

A sharp-pointed hand tool used to scratch fine layout lines on sheet metal; a steel rule guides it for accurate marking out.

A hardened steel punch struck with a hammer to make a small conical indentation that locates a drill point and prevents it wandering.

A layout tool with two adjustable steel legs used to scribe circles and arcs or to step off equal distances along a line.

Hand shears with short hardened blades and compound leverage, used for straight or curved cuts in thin sheet metal.

A machine shear with a long straight blade that cuts sheet metal along a straight line, held by a clamp and operated by a treadle or power.

A machine tool that removes square or rectangular corner sections from sheet metal so that flanges can be folded without overlapping material.

A hand or power folding machine with removable fingers that allows boxes and pans with upstanding flanges to be formed without the fingers fouling the work.

A powered machine that forms sheet metal between a punch and die, producing straight bends to a controlled angle along the full width of the workpiece.

A forming process in which sheet metal is passed between rollers to curve it into cylinders or cones, or to reduce its thickness.

A machine with three adjustable rollers used to bend sheet metal into curved sections; the top roller is adjustable for radius.

A permanent fastening method in which a ductile metal pin is passed through aligned holes and its tail is deformed to clamp the parts together.

A blind rivet set by a hand tool that pulls a mandrel through the rivet body, expanding its tail and snapping off flush.

The centre-to-centre distance between adjacent rivet or fastener holes, chosen to give a sound joint without tearing the sheet between holes.

The distance from the centre of a rivet or fastener hole to the nearest edge of the sheet, kept large enough to prevent the metal tearing out.

A joint formed by interlocking and folding the edges of two sheet metal pieces, often with a sealant, to produce a leak-resistant connection.

A low-temperature joining process in which a filler metal melts and wets the cleaned surfaces, forming a joint without melting the parent metal.

A joining process using a filler metal that melts above 450 degrees Celsius but below the melting point of the parent metal, drawn into the joint by capillary action.

A chemical paste or liquid applied during soldering or brazing to dissolve oxides and prevent re-oxidation, allowing the filler metal to wet the joint.

A hand saw with a fine-toothed replaceable blade held under tension in a frame, used for cutting bar stock and sheet too thick for snips.

A hardened steel tool with cut teeth used to remove small amounts of metal, smooth edges, and correct burrs left by cutting operations.

The removal of sharp raised edges, or burrs, produced by shearing, sawing, or drilling, usually with a file, scraper, or abrasive tool.

A rotating cutting tool, held in a chuck or drill press, that produces cylindrical holes in sheet metal; a centre punch mark locates it.

Items worn to protect the body from workshop hazards, such as safety glasses, gloves, hearing protection, and protective footwear.

A physical barrier or interlock fitted around moving parts of machinery to prevent operators from reaching dangerous areas such as blades or rollers.

A documented process that identifies workshop hazards, evaluates the likelihood and severity of harm, and records control measures to reduce risk.