Red Seal Sheet Metal Worker key terms

A procedure for isolating energy sources, applying a personal lock and tag, and verifying zero energy before servicing equipment, so that a machine cannot be started or release stored energy while someone is working on it.

A documented review of a work task that identifies potential sources of injury, evaluates the risk of each, and records the controls chosen to reduce that risk before work begins.

Wearable gear such as safety glasses, gloves, hearing protection, and respirators that shields the worker from hazards which cannot be eliminated or controlled at the source.

The selection, fit testing, and use of respirators to protect against airborne contaminants such as welding fume, dust, or solvent vapour when ventilation alone does not reduce exposure below limits.

An enclosed or partially enclosed area with restricted entry and exit, not designed for continuous occupancy, where hazards such as poor air quality or engulfment may exist and entry requires a permit and attendant.

A system of guardrails, personal fall arrest, or travel restraint used to prevent or stop a fall when working at height, including on roofs, scaffolds, and aerial work platforms.

A temporary elevated platform and its supporting structure used to provide safe access and a working surface at height, which must be erected, inspected, and used according to the manufacturer and regulations.

A mobile machine with a platform that raises workers to height, such as a scissor lift or boom lift, requiring familiarity with its controls, load limits, and stability on the surface where it operates.

A document supplied with a hazardous product that lists its ingredients, physical hazards, health effects, first aid, and safe handling and storage requirements, used to plan controls before the product is used.

A drawing method that shows an object from several directions on separate views, such as front, top, and side, arranged in a fixed relationship so the shape can be read without distortion.

A drawing view looking straight down at a building or object from above, showing layout, dimensions, and positions of walls, ducts, and equipment in the horizontal plane.

A drawing view showing the vertical face of a building or object, used to locate heights, openings, and the vertical position of equipment or architectural features.

A view produced by imagining a cutting plane through an object and showing the cut surface, used to reveal internal construction, assembly details, and hidden relationships that exterior views cannot show.

An enlarged drawing of a specific part of a larger assembly or building, showing dimensions, materials, and joining methods in enough detail to fabricate or install that portion.

A drawing prepared by the fabricator or contractor that translates design intent into specific dimensions, materials, and assembly details for a component, submitted for review before fabrication begins.

A list accompanying a drawing or project that itemizes each component, its material, size, quantity, and often its part mark, used to order stock and plan fabrication and assembly.

A fixed reference point, line, or surface from which measurements are taken, so that dimensions on a drawing and on the work can be compared consistently from a common origin.

A marked, known elevation or position on the site or structure, such as a surveyor's pin or a floor line, used as the starting reference for setting out work.

An extra amount added to a dimension to account for thickness, clearance, seams, or fit, so the finished assembly meets the required size after forming and joining.

The process of laying out the true flat shape of a part on sheet before cutting, using projection and geometric construction so the formed piece matches the required three-dimensional shape.

A layout method for parts whose surfaces are formed by parallel lines, such as cylinders and prisms, where element lines are projected to produce the flat pattern.

A layout method for cone-shaped and pyramid-shaped parts, in which element lines radiate from an apex and are swung to a true-length arc to build the flat pattern.

A layout method for transition pieces and irregular shapes, where the surface is divided into a series of triangles whose true lengths are found and then assembled into the flat pattern.

The length of the neutral axis along a bend that must be included in the flat pattern so the formed part reaches the intended dimensions, calculated from material thickness, bend radius, and bend angle.

The amount subtracted from the sum of the outside dimensions of a formed part to obtain the correct flat blank length, derived from the bend allowance and the geometry of the bend.

The imaginary line within the thickness of a bent sheet where the material is neither stretched nor compressed, whose length is used to compute the flat pattern for a bend.

A standardized number indicating the thickness of sheet metal, where a higher number generally means thinner material and the actual thickness varies between ferrous and non-ferrous standards.

Steel coated with a zinc layer to resist corrosion, commonly used for ductwork and flashing, which must be handled and welded with attention to zinc fume and coating damage.

A corrosion-resistant steel alloy containing chromium, used in kitchens, food service, and chemical environments, which work-hardens when formed and requires different cutting and welding practices than carbon steel.

A lightweight, corrosion-resistant, non-ferrous metal often used for ductwork, flashings, and trim, which requires dedicated tooling and special welding processes because it does not behave like steel.

A machine that cuts sheet metal by driving a moving blade past a fixed blade, producing straight cuts, and which requires correct blade clearance and guarding of hands and fingers.

A machine that forms sheet metal by pressing it between a punch and die to create bends, with the bend angle and position set by the operator and the tooling.

A machine with adjustable rollers that curves sheet metal into cylinders and arcs by passing the material between them, with roll spacing controlling the radius of curvature.

A machine that removes square or angular corner cuts from sheet metal so that adjacent edges can be folded and joined without interference, commonly used before forming boxes and duct fittings.

A joint formed by folding and interlocking the edges of two sheet metal pieces, such as a Pittsburgh or double seam, which is then usually locked or soldered to make it tight.

A formed metal strip, often S-shaped or drive-on, used to join and stiffen the edges of duct sections or to attach ductwork to structure, allowing assembly without welding.

A filler metal melted at relatively low temperature to join metal surfaces, used in sheet metal work for sealing seams and joints where the base metal is not melted.

A joining process in which a filler metal melts at a temperature above that used for soldering but below the melting point of the base metal, producing a strong joint without melting the parts.

A permanent fastener installed by deforming its shank through the work, used to join sheet metal where disassembly is not required and where heat from welding is undesirable.

Sheet metal components installed to shed water at roof edges, walls, penetrations, and joints, directing moisture away from the building envelope and preventing entry at vulnerable locations.

A metal profile at the edge of a roof that sheds water clear of the fascia and underlying construction, preventing water from running back under the roofing material.

A metal component attached above base flashing to cover and protect the top edge of the flashing, shedding water away from the wall and preventing moisture from entering behind it.

A support, such as a rod, strap, or wire, that carries the weight of ductwork or pipe from structure above, spaced according to the size and weight of the system being supported.

A chamber or duct section that distributes air to or collects air from several branches, often connected directly to air-handling equipment and required to be sealed and supported accordingly.

An adjustable blade installed inside ductwork to regulate airflow to a branch or zone, set during balancing and then locked in position to maintain the designed distribution.

The outward pressure exerted by air against the inside walls of a duct system, measured during testing and balancing to confirm airflow and to check for leakage and excessive resistance.

The process of measuring and adjusting dampers, fans, and terminal units so that each space receives its design airflow within acceptable tolerance, documented in a balancing report.