NCCER Ironworker key terms

A tradesperson who fabricates, assembles, and installs structural steel, precast concrete, ornamental metal, and reinforcing steel on construction projects. Work includes rigging, welding, bolting, and placing materials per engineered drawings.

Fabricated steel members such as beams, columns, and girders that form the load-carrying frame of a building or bridge. Ironworkers align, bolt, and weld these members into the completed structure.

The planning and execution of lifting loads with slings, shackles, hooks, and cranes. Ironworkers select rated hardware, calculate load weight and sling angle effects, and control the load during the lift.

The angle between a sling leg and the horizontal load. As the angle decreases, tension in each leg increases, so capacity drops; a two-leg sling at 30 degrees carries far less than at 60 degrees.

The maximum load a rigging component or assembly is rated to lift in a specified configuration. It is established by the manufacturer and reduced for conditions such as sling angle, wear, or softeners.

A U-shaped rigging connector closed with a pin or bolt, used to join slings to hooks, eyes, or lifting lugs. Screw-pin shackles must be fully seated and never side-loaded beyond rating.

A crane manufacturer's table showing lifting capacity for given boom length, radius, and boom angle. The operator and rigger must confirm the planned lift falls within the charted capacity for the crane's configuration.

The point at which an object's weight is balanced in all directions. Rigs must attach above this point so the load hangs level and does not tip during hoisting.

A rope tied to a suspended load and handled by a worker on the ground to control rotation and swing. It keeps the load from spinning into workers or structures during the lift.

A structural joint designed to transfer bending moment as well as shear between members, usually by welding or high-strength bolting of flanges and plates. It provides frame rigidity.

A joint that transfers primarily vertical shear between a beam and its support, typically using a shear tab or clip angle with bolts or welds. It permits some rotation and does not resist moment.

A structural fastener such as an A325 or A490 bolt installed to a specified tension to clamp steel plies together. Installation follows turn-of-nut, calibrated wrench, or tension-control methods per project specifications.

The contact surface between bolted steel plies in a connection. It must be clean and free of paint, mill scale, or debris where slip-critical connections require the specified surface condition.

The vertical alignment of a column or frame, checked with a level, plumb bob, or transit. Ironworkers use guy wires, shims, and temporary bracing to bring members to plumb before final connections.

Temporary cables, rods, or struts installed to stabilize steel members until permanent connections are completed. Bracing is removed only when the structure is stable and per the erection plan.

A documented sequence describing how steel members will be hoisted, connected, and stabilized, including crane positions, bracing, and safety measures. Ironworkers follow it to keep the structure stable at every stage.

An ironworker who works at the leading edge or aloft to align and secure steel members as they are hoisted into place. Connectors work from controlled access equipment and use fall protection.

Personal and collective systems such as harnesses, lanyards, anchors, and guardrails that prevent or arrest falls from elevation. Ironworkers must be tied off when exposed to fall hazards above the required threshold.

Decorative and functional metal components such as stairs, railings, handrails, and architectural grilles. Ironworkers fabricate, fit, and install these items to specified dimensions and finishes.

Detailed drawings showing the size, shape, spacing, and location of reinforcing steel and related embeds. Ironworkers and rodbusters use them to position bars correctly before concrete placement.

Deformed steel reinforcing bar embedded in concrete to carry tensile and shear forces. It is cut, bent, and tied into cages and mats per placing drawings before the concrete is poured.

The center-to-center distance between parallel reinforcing bars, specified on placing drawings. Correct spacing ensures concrete can flow around bars and that the design strength is achieved.

The distance from the outer surface of concrete to the nearest reinforcing bar. Adequate cover protects steel from corrosion and fire and is maintained with bar supports and spacers.

A device, often called a chair or bolster, that holds reinforcing bars at the required elevation within a form. It maintains concrete cover and correct bar position during placement.

Soft annealed wire used to secure crossing reinforcing bars together so the cage holds its shape. Ties are made with a tie tool and twisted snugly without damaging the bar.

A colloquial term for reinforcing bar used by rodbusters. It refers to the deformed steel bar placed in concrete to resist tension and shear forces.

A reinforcing ironworker who cuts, bends, places, and ties reinforcing steel in forms for concrete structures. The trade requires reading placing drawings and maintaining bar position and cover.

A permanent bend made in reinforcing steel to fit the structure, defined by bar size, bend diameter, and hook dimensions. Bends must follow code and placing drawings to preserve bar strength.

A 90-degree or 180-degree bend at the end of a reinforcing bar, dimensioned by code to develop anchorage in concrete. Hooks are required where straight bar length is insufficient.

The length of embedment needed for a reinforcing bar to transfer its design force to the surrounding concrete without pulling out. It depends on bar size, concrete strength, and hook or coating conditions.

An overlap of two reinforcing bars through which force transfers from one bar to the other. The overlap length is specified by code and drawings and is tied to hold position.

A manufactured coupler or device that joins two reinforcing bars end to end to transfer force. It is used where lap splices are impractical or where the design requires full bar continuity.

A method in which steel tendons are tensioned after concrete hardens to compress the concrete and resist loads. Ironworkers install anchors, ducts, and tendons and assist with stressing operations.

Concrete members cast and cured in a plant and then transported to the site for erection. Ironworkers rig and align precast panels, beams, and planks and make the final structural connections.

A steel plate with welded studs or anchors cast into concrete to provide a connection point for steel or precast members. Ironworkers verify its location and weld or bolt attachments to it.

A weld made at the construction site to join members or connections rather than in the fabrication shop. Field welds require qualified welders, proper fit-up, and inspection per project requirements.

A bracket or angle welded or bolted to a column or girder to support the end of a beam during erection. It aids alignment and transfers shear into the supporting member.

A tapered steel pin used to align bolt holes in steel connections before bolts are installed. It is driven into the hole to bring plies into alignment and is removed as bolts are placed.