What is Quality Control (QC) in a steel fabrication shop?

QC is the systematic inspection and testing of materials and products during and after fabrication to verify conformance to drawings, specifications, and standards. Typical QC includes material verification, fit-up and weld inspections, dimensional checks, coating/DFT checks, and final release.

How is QC different from Quality Assurance (QA)?

QA defines the system that prevents defects (procedures, training, WPS control, calibration). QC detects and documents defects in the actual product and verifies they are corrected before delivery. Both work together to deliver consistent quality.

Who is responsible for QC in a small shop?

Either a dedicated quality inspector or the production lead performs QC. Responsibility is assigned per job, with competence proven by training and, where required, certifications (e.g., visual weld inspection).

What inspections are typically required on a structural steel job?

Material receiving and MTR check, fit-up and root pass verification against WPS, in-process visual weld inspection, dimensional inspection versus drawings, coating surface prep and DFT measurements, and a final inspection prior to shipment.

Which standards define acceptance criteria for QC?

Acceptance criteria come from the project specification and referenced codes/standards such as AWS D1.1 for structural welding, ISO/EN 1090 requirements, ISO 5817 for weld imperfections, and ISO 12944/SSPC for coatings. The job traveler should reference the applicable criteria.

What documents should we keep for QC records?

Material certificates (MTRs), WPS with supporting PQRs and welder qualifications, inspection and test plans (ITPs), in-process and final inspection checklists, NDT reports, DFT logs, calibration certificates, nonconformance reports (NCRs) and corrective actions, and final release documentation.

What is an ITP (Inspection and Test Plan) and why use it?

An ITP lists each inspection point in the process with the method, acceptance criteria, and responsibility, including hold/witness points for the client. It prevents ad-hoc checks, clarifies expectations, and provides a backbone for QC records.

When is NDT (non-destructive testing) required and which methods are common?

NDT is used when specified by code or the contract, or when visual inspection is insufficient. Common methods include MT (magnetic particle), PT (dye penetrant), UT (ultrasonic), and RT (radiography). Requirements and extent are defined in the ITP/specification.

How should we verify welding is performed per WPS?

Check that the correct WPS is available at the station, verify essential variables (process, filler, polarity, parameters, preheat/interpass), and record fit-up, root, and final visual results. Link welder ID and heat numbers for full traceability.

What measuring and test equipment needs calibration?

Tape measures, calipers, levels, DFT gauges, weld gauges, thermometers/pyrometers, torque wrenches, and pressure/vacuum gauges used for acceptance decisions. Calibrate to a defined interval and keep certificates traceable to each job.

How do we control drawings and revisions during QC?

Maintain a single controlled source for current drawings. Travelers and tablets must show the active revision; obsolete prints are removed from the floor. Any redlines or RFIs are recorded and tied to the job record.

What is the best way to handle nonconformances and rework?

Issue an NCR with part ID, defect description, cause, and disposition (rework, repair per WPS, use-as-is with concession, or scrap). Record corrective actions and verify by re-inspection before the hold is lifted.

How do we document coating quality (paint/galvanizing)?

Record surface prep, environmental conditions, batch/lot numbers, and DFT readings per coat and location. For galvanizing, capture kettle certificates and any repairs. Compare results against the specified system and standard.

When should we use a third-party inspector?

Use third-party inspection when contractually required, for specialized NDT, or when independence is needed (critical structures, client or regulatory audits). Define scope and hold/witness points in the ITP.

How can Eziil support QC in a small fabrication shop?

Eziil links WPSs, drawings, and checklists to each operation on tablets; captures photos, measurements, and e-signatures; tracks NCRs and revisions; and lets you export an audit-ready QC pack (MTRs, inspections, DFT, NDT) for clients and standards such as ISO 9001 or EN 1090.

What does an audit-ready QC package typically include?

Contract/spec references, controlled drawings, ITP, WPS/PQR/WPQ, material certificates with heat traceability, in-process and final inspection records, NDT/coating logs, calibration evidence, NCRs/corrective actions, and the final release certificate tied to the shipped items.

Quality Control (QC)

What is Quality Control (QC) in steel fabrication?

Quality Control (QC) is the process of inspecting and testing products during and after production to ensure they meet the specified quality standards and design specifications.

In steel fabrication, QC activities include material inspections (verifying certified mill test reports and grades), fit-up and weld inspections (checking weld sizes, lengths, and detecting any defects via methods like visual inspection or NDT), dimensional checks of fabricated pieces against drawings, and a final inspection of coating and overall assembly before delivery.

The primary goal of Quality Control is to catch any defects or deviations so that they can be corrected, thus preventing faulty products from reaching the customer.

For a small shop, Quality Control might be performed by a dedicated quality inspector or by the shop lead as part of their role.

It’s important that QC is systematic. For example, using checklists at key stages (after welding, after painting), rather than ad hoc.

Effective Quality Control helps maintain the shop’s reputation (especially if they are certified to standards like ISO 9001 or AISC certification), reduces rework and project delays, and ensures compliance with any code requirements (like AWS D1.1 welding criteria or paint thickness requirements).

While Quality Assurance (QA) is about the systems to prevent defects, Quality Control is about detecting issues in the product itself and fixing them. In practice, both concepts work hand-in-hand to deliver consistent quality.