Technical Reading — Welding Documents, SDS, and Codes

Why Technical Reading Matters in Welding

Welding is a precision trade governed by written documents. Before you strike an arc on any structural or pressure job, someone has already recorded the exact conditions that produce an acceptable weld—and your job is to read those conditions accurately and follow them. Misreading a preheat temperature, skipping a line on a Safety Data Sheet, or mistaking one joint type for another can cause a weld to fail, a structure to collapse, or a worker to be injured. This lesson builds the document-reading skills you will use every day on the job and that are tested in every credential you will earn in this program.

The Welding Procedure Specification (WPS)

A Welding Procedure Specification is the written recipe for a weld. It tells every welder on a project exactly how to make a joint so that the finished weld meets the applicable code. Under AWS D1.1, the structural welding code for steel, a WPS must be either prequalified (meeting all prequalified joint and process requirements stated in the code) or qualified by testing. Either way, the document contains the same categories of information.

Key fields you must locate and read correctly:

• Base metal and P-Number/Group: Identifies the steel or alloy being joined. AWS D1.1 categorizes base metals; ASME Section IX uses P-Numbers. Knowing the metal group tells you which filler is compatible and what preheat is required.
• Filler metal classification: Given in AWS classification format (for example, E7018 for a low-hydrogen SMAW electrode). The prefix tells you process; the numbers encode tensile strength and usability characteristics.
• Preheat and interpass temperature: Preheat is the minimum temperature the base metal must reach before welding begins. Interpass temperature is the maximum temperature allowed between passes on multi-pass welds. Both are measured with temperature-indicating sticks, contact thermometers, or pyrometers. Ignoring these values causes hydrogen cracking in high-strength steels.
• Travel speed range: Expressed in inches per minute. Too fast leaves inadequate fusion; too slow overheats the base metal and produces excessive distortion.
• Shielding gas: Type and flow rate. Wrong gas or flow rate causes porosity.
• Post-Weld Heat Treatment (PWHT): Some thick or high-strength joints require stress relief after welding. The WPS states whether PWHT is required and at what temperature and hold time.
• Position, joint type, root opening, backing, and pass sequence: Together these fields describe the geometry of the joint and the order in which layers are deposited. Never substitute a different joint geometry without formal code approval.

When performing the WPS scavenger hunt, scan the document by section heading first, then read each field carefully. Record the exact value—not your memory of it.

Safety Data Sheets (SDS) and the GHS Format

Every hazardous chemical in your workplace—including electrode coatings, flux, shielding gases, and cleaning solvents—must have a Safety Data Sheet available to workers. Since 2012, OSHA's Hazard Communication Standard (HazCom) has required SDS documents to follow the Globally Harmonized System (GHS) format, which organizes information into 16 numbered sections. You are required to read and understand the SDS before you handle or use any product.

Sections most critical to welders:

• Section 2 – Hazard Identification: Lists signal words (Danger or Warning), hazard statements, and pictograms. This is your quick-reference for the severity of the hazard.
• Section 8 – Exposure Controls / Personal Protection: States the permissible exposure limit (PEL) and threshold limit value (TLV) for each hazardous component, and specifies required PPE—respirator type, glove material, and eye protection.
• Section 4 – First-Aid Measures: Describes what to do immediately if someone is exposed by inhalation, skin contact, or ingestion.
• Section 13 – Disposal Considerations: Some electrode flux components are regulated as hazardous waste. Improper disposal violates federal and state environmental law.

For SMAW electrodes such as E6010 or E7018, the SDS will flag iron oxide, manganese, and silica fume as inhalation hazards. Always weld in a well-ventilated area; use local exhaust ventilation when welding in confined spaces; wear the respirator specified in Section 8 when ventilation is inadequate. Lockout/tagout the ventilation interlock equipment before servicing ductwork. Never rely on memory—look up the SDS for each new product.

Reading AWS D1.1 Code Text

Code documents are written in precise, formal language where every word carries weight. AWS D1.1 uses defined terms that have specific technical meanings different from everyday English. When you encounter an unfamiliar term, look it up in the code's own definitions section before assuming you understand it.

Strategies for code reading:

1. Read the clause number and heading first to understand context.

2. Look up every defined term in the definitions or glossary section.

3. Note the mandatory language: shall means required; should means recommended.

4. Cross-reference tables (joint details, preheat tables) using the exact designation given in the clause.

Building this habit now prepares you for the written and practical portions of the AWS D1.1 Certified Welder exam, the NCCER written assessments, and ASME Section IX procedure reviews you will encounter as your career advances.

Connecting the Documents

On a real job, a WPS, an SDS, a work order, and a code reference table are used together. The work order tells you the scope; the WPS tells you how to weld it; the code reference table confirms the WPS is valid for your joint; the SDS tells you how to protect yourself doing the work. Reading any one of them in isolation is not enough. Practice finding the connections between documents every time you practice reading them.