I-CAR Non-Structural key terms

A vehicle structure in which stamped steel panels are welded together to form a single load-bearing shell, so the body itself carries the vehicle's weight and crash forces rather than a separate frame.

A design in which a separate, heavy steel ladder frame supports the powertrain and suspension, and the body panels bolt to it. Common on trucks and large SUVs, where the body does not carry primary loads.

The engineered way a vehicle absorbs and redirects crash forces through crush zones, reinforced rails, and load paths so occupants experience lower deceleration and the passenger compartment stays intact.

A deliberately weaker portion of the front or rear structure designed to fold and deform in a collision, absorbing kinetic energy before it reaches the rigid occupant safety cage.

The reinforced central structure around the driver and passengers, built from high-strength materials and designed to resist deformation so survival space and restraint geometry are preserved in a crash.

Steel grades with elevated yield strength achieved through alloying or processing. They resist deformation well but are sensitive to heat, so OEM repair procedures often restrict or prohibit straightening and welding on them.

The strongest class of automotive sheet steel, frequently used in door intrusion beams, B-pillars, and bumper reinforcements. Heat or bending typically destroys its properties, so replacement rather than repair is usually required.

A body design using aluminum extrusions, castings, and stampings instead of steel. It requires dedicated tools, isolation from steel to prevent galvanic corrosion, and OEM-specified rivet-bonding rather than conventional welding.

Accelerated corrosion that occurs when two dissimilar metals, such as aluminum and steel, are joined in the presence of an electrolyte. Repairers must isolate the joint with coatings, sealers, or specified barriers.

Replacing only the damaged portion of a panel by cutting it at an OEM-approved location and joining a new section. The procedure is allowed only where the vehicle maker publishes a specific sectioning guideline.

The exact cut point and shape specified by an OEM for a partial panel replacement, chosen to avoid high-stress and high-strength areas. Cutting outside this location can compromise crash performance.

The factory-style welding process in which water-cooled electrodes clamp overlapping panels and pass current to fuse them at the contact point. Reproducing it is the preferred attachment method for welded steel panels.

A weld made by filling a hole punched or drilled in the outer panel to fuse it to the panel beneath. It is a common alternative when a spot welder cannot reach the joint.

A conductive, zinc-rich coating applied to bare mating surfaces before welding. It protects the hidden joint from corrosion while still allowing current to pass and a sound weld to form.

The band of base metal adjacent to a weld that is altered by welding heat but not melted. In high-strength steels it can lose strength, so OEM procedures may limit welding or require reinforcement.

A joining method that combines structural adhesive with rivets, used widely on aluminum and mixed-material bodies. The adhesive carries load and seals the joint while the rivets hold alignment during cure.

A two-part epoxy or similar product formulated to carry loads in a bonded joint, not just seal it. It requires correct ratio mixing, clean surfaces, and the OEM-specified clamp or cure time.

The controlled gap of adhesive between two bonded panels, maintained with glass beads or spacers. Too thin or too thick a bond line reduces joint strength, so the OEM specification must be followed.

The practice of separating dissimilar metals and sealing bare surfaces so moisture cannot bridge them. It is essential on aluminum-to-steel joints and around repaired areas to prevent galvanic corrosion.

The combination of coatings, primers, cavity waxes, and sealers applied to restored bare metal and enclosed areas so a repaired panel matches the factory's original rust resistance.

A creeping, waxy coating sprayed into enclosed box sections and pillars after repair to coat interior surfaces that cannot be painted or reached by hand.

A flexible, paintable compound applied over welded or bonded panel joints to keep water out and restore the factory appearance. It must be applied to correctly prepared and primed surfaces.

A polyester-based paste used to smooth minor surface irregularities before primer. It is not a substitute for metal straightening and must be applied thinly over properly prepared, primed steel.

A thin, fast-setting filler used to fill pinholes and fine scratches in body filler or primer. It is applied in very thin coats and is not intended for structural or deep surface correction.

A light mist of contrasting color applied over primer or filler so sanding scratches and low spots become visible. It is sanded away during blocking to reveal the true contour.

Sanding with a rigid or semi-rigid pad to level filler and primer and reveal high and low spots. It produces a flatter, truer contour than hand sanding with fingers alone.

A technique that massages shallow dents out from behind the panel using specialized rods and glue pulling, preserving the original finish. It is limited to dents where the paint is intact and access exists.

A paintless dent repair method in which a tab is bonded to the dented surface with hot glue and pulled to raise the metal, used where the back of the panel cannot be reached.

The tendency of a deformed steel panel to return toward its original shape when force is applied correctly. Skilled technicians use it to plan pushing and pulling sequences during dent removal.

The even spacing and surface alignment between adjacent panels, such as a hood and fender. Correct gaps and flushness are checked with gauges and adjusted before final fastening.

Adjusting hinges, latches, and mounting points so a replacement or removed panel fits with correct gaps, flushness, and operation. It is performed with fasteners loose, then tightened in sequence.

Placing thin spacers at a mounting point to raise or shift a bolted panel so gaps and flushness meet specification. Shims must not be used to hide underlying structural misalignment.

A foam or plastic component behind the bumper fascia that deforms to absorb low-speed impact energy. It is typically single-use and replaced after a collision rather than reused.

The rigid steel or aluminum beam behind the fascia and absorber that spreads impact loads into the vehicle structure. It must be inspected for cracks and replaced if damaged.

The flexible plastic or urethane outer cover of a bumper assembly. It can often be repaired rather than replaced, and it usually carries sensors, grilles, and trim that must be transferred.

Joining cracked thermoplastic parts by melting them together with a hot-air, hot-plate, or friction welder and a compatible filler rod. Identifying the plastic type is required for a sound repair.

Determining the specific polymer of a part, often from an ISO code molded into its back, so the correct repair method, adhesive, and filler rod can be selected.

A diagnostic scan of all modules performed before repairs begin to record existing fault codes and confirm which systems are communicating. It protects both the shop and the customer.

A diagnostic scan after repairs and calibration to confirm no fault codes remain and all safety and driver-assistance systems are functioning. It is documented in the repair file.

The aiming or relearn procedure required for cameras, radars, and other sensors after replacement, removal, or a change in ride height. It may be static in a controlled bay or dynamic on a test drive.

Cameras, radars, and sensors that support functions such as automatic emergency braking, lane keeping, and adaptive cruise. Their mounting location and aim are critical to safe operation.

A documented request to the insurer for additional repair operations and parts discovered after the original estimate, such as hidden damage found during teardown.

The systematic disassembly of damaged areas to expose hidden damage and identify all needed parts and operations before finalizing an estimate. Findings are photographed and recorded.

The written and photographic record of the vehicle's condition, procedures performed, materials used, scans, and calibrations. It supports quality control, warranty, and any later liability questions.