AWS D1.5 Endorsement key terms

A bridge component whose failure would likely cause the entire structure or a major portion of it to collapse, so its welds require tighter inspection and toughness requirements.

The maximum stress a material can carry before breaking, measured in ksi or MPa; it determines the required filler metal strength for a given base metal.

The stress at which a material begins to deform permanently, used to classify steels and set minimum strength for filler metals in bridge welding.

The standard specification for structural steel for bridges, defining grades and toughness levels such as Grade 345 (50 ksi) and Grade 250 (36 ksi) commonly welded under D1.5.

A measure of a steel's or weld's resistance to brittle fracture, determined by striking a notched specimen; D1.5 sets minimum energy values for certain grades and service conditions.

The alphanumeric designation (such as F7A2-EM12K) that encodes the deposited strength, toughness, and composition of a welding consumable.

A consumable selected so its deposited strength and toughness are compatible with the base metal being joined, avoiding overmatching that can reduce toughness.

The energy delivered per unit length of weld, calculated from current, voltage, and travel speed; excessive or insufficient heat input can degrade toughness and cause defects.

The temperature of the base metal and previously deposited weld metal immediately before the next pass; D1.5 limits maximum values to protect toughness and mechanical properties.

Heating the base metal before welding to slow cooling, reduce hydrogen cracking risk, and improve fusion and ductility; minimum values depend on steel grade and thickness.

Delayed cracking caused by hydrogen trapped in the weld, often occurring hours after cooling; controlled by preheat, low-hydrogen consumables, and proper storage.

A covered electrode or consumable with low moisture content, stored and handled to prevent hydrogen pickup that could cause delayed cracking in bridge welds.

A written document that specifies the variables and steps for producing a weld so it meets the code; it must be supported by a procedure qualification record.

The record of the test welds and mechanical tests used to prove that a WPS can produce sound welds meeting D1.5 requirements.

A welding parameter, such as a change in filler metal or current range, that affects the mechanical properties of the weld and therefore requires requalification if changed.

A joint configuration, such as a specific groove or fillet, that D1.5 permits without separate joint qualification, provided the specified dimensions and conditions are met.

A weld made in a groove between two members, used for full-penetration or partial-penetration joints; common in bridge splices and connections.

A groove weld that extends through the entire thickness of the joined members, typically required for fracture-critical and primary tension applications.

A groove weld that does not extend through the full thickness of the joined members, used where lower strength is acceptable and permitted by the design.

A triangular weld joining two surfaces at an angle, sized by leg or throat; commonly used for stiffeners and connections in bridges.

The shortest distance from the root of a fillet weld to its face, used to compute the effective strength capacity of the weld.

The length of a weld over which the full design strength may be counted, accounting for end returns and other reductions specified by the code.

The planned inspection and documentation activities, including visual and nondestructive examination, used to verify that completed welds meet D1.5 acceptance criteria.

Examination of welds by eye and with aids such as magnifiers or gauges to detect surface discontinuities, undercut, and dimensional nonconformities before other testing.

Inspection methods such as ultrasonic, radiographic, magnetic particle, or dye penetrant testing that reveal internal or surface flaws without damaging the weld.

An NDE method that uses high-frequency sound waves to detect internal discontinuities in welds; often required for full-penetration and fracture-critical welds.

An NDE method that uses X-rays or gamma rays to produce images of internal weld discontinuities, useful for volumetric flaws such as porosity and slag.

A surface and near-surface NDE method that uses magnetic fields and iron particles to reveal cracks and discontinuities in ferromagnetic materials.

A surface NDE method that applies a visible or fluorescent liquid to reveal open discontinuities such as cracks and porosity in welds.

A groove melted into the base metal at the weld toe that is not filled by weld metal; it reduces cross-section and is limited by acceptance criteria.

Gas pockets trapped in solidified weld metal, appearing as rounded voids; excessive porosity reduces strength and is controlled by acceptance limits.

Nonmetallic solid material trapped in weld metal or between weld passes, often detected by radiography or ultrasonics and limited by acceptance criteria.

A discontinuity where weld metal fails to bond to the base metal or to a previous pass, reducing joint strength and typically rejected in critical welds.

A condition where the weld does not extend through the intended joint depth, leaving an unbonded root region; serious in full-penetration welds.

Testing and certification of an individual welder's ability to produce sound welds to the code, typically by welding test coupons that are then inspected and tested.

A qualified person responsible for verifying that welding procedures, materials, and completed welds conform to D1.5 requirements and documentation.

Techniques such as balanced welding, backstep sequences, and fixturing used to limit shrinkage stresses and dimensional changes in welded bridge assemblies.

The planned order in which welds or passes are made, chosen to control distortion, residual stress, and heat input in the completed structure.