Consumable evidence · Annex B · Clause 7.3
What proves low hydrogen, and how should consumables be handled?
A diffusible-hydrogen result, a classification suffix, an Annex B hydrogen level and a shop storage record answer different questions. Keep the evidence tied to the actual product and its condition when used.
Four records that must not be conflated
| Record or label | What it establishes | What it does not establish by itself |
|---|---|---|
| AWS A4.3 test report | A measured diffusible-hydrogen result for the tested electrode or consumable combination and stated test/preparation condition. | The result for a different brand, lot, wire/flux combination, exposure history, or production electrode after uncontrolled handling. |
| AWS A5.1/A5.5 classification suffix such as H4, H8 or H16 | A classification hydrogen designator for a product classified to the applicable electrode specification. | A4.3 test evidence for the particular material as stored and issued to a production welder, or a universal handling allowance. |
| Annex B H1, H2 or H3 | A hydrogen level used with chemistry, thickness and restraint in the hydrogen-control method. | A product certification or a measurement. Some H1/H2 cases use conditional representative assumptions instead of an actual measured result. |
| Clause 7.3 issue, storage and exposure record | Whether covered consumables stayed within the applicable code handling route and time limits. | The consumable’s classification, actual diffusible-hydrogen result, or permission to lower a preheat requirement. |
Retain the complete classification, product identity, lot or batch where available, manufacturer documentation, applicable test report and issue/return history. For SAW, the electrode/flux combination matters; do not transfer one combination’s evidence to another.
A4.3 is a test result, not a product nickname
When a code provision requires a diffusible-hydrogen limit, use an applicable AWS A4.3 report showing the product or combination tested, the measured value, and the test condition. Check that the report matches the actual consumable identity and that production storage/exposure conditions do not invalidate the intended use of that evidence.
Do not infer a numeric test result from “low hydrogen,” “H4,” a datasheet headline, or the fact that an electrode was kept warm. A classification suffix and an A4.3 result are related product evidence but have different scope. If the decision depends on a specific maximum, compare the report value and units directly with the relevant clause or table limit.
Annex B hydrogen levels are method inputs
For the Annex B hydrogen-control method, the 2025 base edition defines the H levels using the following test or coating-moisture criteria and also gives representative practice assumptions. These are separate ways of classifying an input; the practice assumption is not a measured production result.
| Annex B level | Defined test or coating criterion | Representative assumption stated by the method |
|---|---|---|
| H1 · Extra-Low | AWS A4.3 diffusible hydrogen <5 mL/100 g deposited metal, or AWS A5.1/A5.5 electrode coating moisture ≤0.2%. | Sealed-container low-hydrogen electrodes baked at 700–800°F [370–430°C] for 1 h and used within 2 h after removal; or clean solid GMAW wire. |
| H2 · Low | AWS A4.3 diffusible hydrogen <10 mL/100 g, or AWS A5.1 electrode coating moisture ≤0.4%. | Sealed-container low-hydrogen electrodes handled under 7.3.2.1 and used within 4 h after opening; or SAW with dry flux. |
| H3 · Not Controlled | Consumables not meeting H1 or H2. | Do not assign H1 or H2 from a product name alone. Annex B uses H = 30 mL/100 g as the representative calculation input for H3. |
For the Annex B susceptibility calculation, use H = 5, 10 or 30 mL/100 g for H1, H2 or H3 respectively, as specified by the method. Those calculation values are not the same as an individual A4.3 report result. The method also needs the required chemistry, the thicker member’s thickness, and an assessed restraint level; an assumed H level cannot make up missing chemistry or restraint evidence.
Annex B hydrogen control is one alternative preheat method with defined inputs and limits. For a Clause 6 WPS, follow its qualification provisions. For a Clause 5 prequalified WPS, do not automatically replace Table 5.11 with a lower Annex B value; the scope and conditions need to support that route. See the minimum-preheat guide and its discussion of separate code paths.
Apply Clause 7.3 to the actual product and issue state
For covered low-hydrogen SMAW electrodes, Clause 7.3.2 uses the complete classification and storage/exposure history. Table 7.1 Column A provides the baseline maximum atmospheric exposure after removal from the original hermetically sealed container or holding oven:
| Classification family shown in Table 7.1 | Column A maximum exposure |
|---|---|
| AWS A5.1 E70XX | 4 h |
| AWS A5.1 E70XXR, E70XXHZR or E7018M | 9 h |
| AWS A5.5 E70XX-X | 4 h |
| AWS A5.5 E80XX-X | 2 h |
| AWS A5.5 E90XX-X | 1 h |
| AWS A5.5 E100XX-X or E110XX-X | 0.5 h |
Table 7.1 Column B can allow longer times only where the applicable classification/product has qualifying test evidence and the required temperature and humidity conditions. Do not treat a familiar “10-hour” allowance as universal. Use the applicable Table 7.1 row and notes for the full classification and actual conditions.
- Keep unused exposed low-hydrogen SMAW electrodes in a holding oven at not less than 250°F [120°C]. Electrodes that become wet are not to be used.
- Clause 7.3 limits rebaking to one time. Follow the applicable specification route and manufacturer’s product instructions; a manufacturer instruction does not erase a code limit.
- For electrodes that remain within their exposure time, return to a holding oven for at least 4 h before reissue, as specified by the processed Clause 7.3 rule.
- Do not extend SMAW electrode times or baking schedules to solid wire, metal-cored wire, tubular wire, or SAW flux without checking their separate applicable requirements.
Over-exposure rebaking has classification-specific minimum times and temperature ranges, and special rules apply to certain quenched-and-tempered steels. A generic shop temperature is not a substitute for checking Clause 7.3.2 and the actual manufacturer’s instructions. This page intentionally does not prescribe a generic redrying schedule.
Follow the manufacturer’s instructions within the code limits
Product instructions supply the operating and conditioning directions for a named product. Record the exact manufacturer, designation, diameter or wire/flux combination, document revision, and any stated reconditioning limit. If instructions differ from the code floor, apply the stricter requirement that governs the project and consumable; do not improvise a drying cycle for a product whose instructions are unavailable.
Do not assume every electrode quiver needs heating, that every sealed package has the same open-package life, or that a low-hydrogen label means an exposed electrode remains acceptable. When product identity, exposure history, moisture condition, or applicable instruction cannot be established, quarantine the affected consumable and resolve that record gap under the project quality process.
A practical evidence check before writing the WPS
- Identify the exact AWS classification, product designation, manufacturer and, for SAW, the electrode/flux combination.
- Decide which requirement is being evaluated: filler classification, measured diffusible hydrogen, an Annex B input, or production storage and exposure.
- For an A4.3-based limit, inspect the test report and confirm product, condition, value, units and applicable code threshold.
- For Annex B, document whether H1/H2 comes from applicable test/coating evidence or a permitted representative assumption, then verify every other method input and applicability condition.
- For Clause 7.3, record sealed-package opening, issue and return times, holding-oven controls, exposure total, condition and any rebake history for the relevant consumable class.
- Check that the WPS’s filler classification and any reduced-preheat path are independently supported. Do not use storage compliance as substitute qualification evidence.
Basis and limits
This guide uses AWS D1.1/D1.1M:2025 base edition plus the registered July 28, 2026 base-edition errata; AMD1 is excluded. Contract-specified editions govern. Relevant provisions include AWS D1.1 Clause 7.3 and Table 7.1, with Annex B hydrogen-control definitions and assumptions. AWS A4.3 test evidence and AWS A5.1/A5.5 classifications are discussed only for the distinctions needed here.
The page summarizes consumable handling and hydrogen evidence. It does not certify a consumable, determine whether a particular test report is acceptable for a project, calculate an Annex B preheat, or complete a WPS. Confirm the actual edition, material, process, full classification, product instructions, storage history and applicable project requirements.