AWS A5.13

SECTION 2What A5.13 classifies, and what it leaves to the procedure

AWS A5.13/A5.13M is the specification for surfacing electrodes for shielded metal arc welding. Classification is based on the chemical composition of the deposited weld metal, with one deliberate exception: tungsten carbide electrodes are classified by the mesh range, quantity and composition of the tungsten carbide granules in the core, not by a bulk deposit analysis.

The published annex includes an approximate deposit hardness table and guidance on characteristics and intended uses. Approximate is the operative word: those numbers are informative, not classification limits. A5.13 also states that safety and health matters lie outside its scope, with references to sources such as ANSI Z49.1; ventilation, protection and the SDS are separate shop-floor documents.

SECTION 3Edition, unit systems and the documents around A5.13

SECTION 4Five alloy families and how a designation is assembled

The A5.13 tables are organised by composition group. The trade commonly speaks of five families: iron-base, cobalt-base, nickel-base, copper-base and tungsten carbide. Reading them as one flat price list is what produces many quotation errors.

Two boundaries: A5.13 has no -15/-16/-17 usability designation — those belong to AWS A5.4 stainless steel covered electrodes. An A5.13 designation does not encode covering type, current, polarity or welding position. The -A in ECoCr-A and the -A in an A5.15 cast iron designation do not share a meaning.

SECTION 5Coverings in surfacing: where the alloy actually comes from

In joining electrodes the covering is usually discussed in terms of arc stability, slag and position. In hardfacing it has an additional job that changes how the product is bought: a substantial part of the alloy content can be delivered through the covering. Published datasheets quote metal recovery figures in the region of 120% to 210% relative to the core wire, and thick-coated products may form little or no covering slag. Two electrodes with similar core wire diameters can therefore deposit quite different amounts of alloy per kilogram consumed.

The covering type is a datasheet attribute, not a field in the A5.13 designation. Where a project needs it written down, it sits elsewhere:

D132, D172, D212 and D207 are brand numbers in Chinese supplier catalogues; EDPCrMo-A4-03 is the model designation under GB/T 984. A D number alone leaves the standard, covering and power supply undefined.

Re-drying values published for hardfacing electrodes vary: 150 °C × 1 h on titania-type products, 300–350 °C × 1 h on low-hydrogen products, and 350 °C × 2 h with a limit on drying cycles on some datasheets. These are examples of published supplier instructions, not a procedure for our products. The batch TDS and the WPS govern.

SECTION 6Three numbers that must be read together

A surfacing enquiry usually arrives with one number copied from a datasheet. A usable specification needs three, and each has a condition attached.

SECTION 7Hardness is a condition, not a classification limit

Annex material in the A5.13 document family includes a table of approximate weld deposit hardness for SMAW. Public third-party abstracts of supplier datasheets show how widely such numbers move with the test condition.

These figures show the shape of the problem, not a specification for any product we supply. Verify against the applicable official text, or omit the numbers from a live page.

What follows for the purchase order

1. State the scale (HRC, HB, HV) and the test method.

2. State the layer number and the base metal for the reading.

3. State where the reading is taken and how the surface is prepared.

4. If a minimum hardness is contractually required, write it as a supplementary requirement with its own method; A5.13 classification does not impose it.

5. Keep hardness and wear behaviour as separate acceptance items; similar macro-hardness can accompany different carbide type, volume and matrix.

SECTION 8Dilution, layer count and the first layer

Dilution is the proportion of melted base metal in the fused deposit. SMAW surfacing is described in published teaching material as having moderate to high dilution relative to low-dilution processes; annex text from the 2000 edition describes roughly 0.5–2 kg/h deposition at dilution levels around 30–50% under stated conditions. Those are illustrative process figures, not a prediction for a given job.

The first layer reads differently because the arc melts into the substrate, iron enters the pool, and the alloying elements arrive diluted. Filler makers therefore publish hardness for a particular layer count, commonly two or three. Some alloy systems allow only two or three layers before cracking becomes a concern, so reducing first-layer dilution increases the usable thickness that retains the intended behaviour.

The AWS annex table on SMAW variables is explicitly described as showing general trends only, and as not covering weldability or weld soundness. It also warns that changing one variable alone may not produce the wanted change, because other parameters move with it.

SECTION 9Selection overview by wear mechanism

The matrix below is a routing aid. It names families to discuss with a supplier, not products to order without a trial.

A recurring mistake described in buying guides is choosing the highest hardness for an impact-loaded component, or placing a hard final deposit over a worn, unsupported profile. Another is comparing consumables by package price without deposition rate, recovery, usable layer count and service life on the same component.

SECTION 10Base metals and the build-up / buttering decision

The substrate is part of the deposit specification: it sets dilution, preheat, interpass limits, thermal-expansion mismatch and the heat-affected zone response.

Two distinct layers are often confused. A build-up layer restores dimensions with a tougher, less costly deposit so that expensive carbide-rich alloy is not used as bulk filler. A buttering / buffer layer manages metallurgical compatibility — dilution, carbon pickup, thermal-expansion mismatch or crack sensitivity — between substrate and top layer. Which is needed, and in what sequence, belongs in the WPS.

We do not give a default recommendation for pressure-containing, load-bearing or safety-related components. The responsible engineer sets the procedure, qualification and inspection plan before a consumable is named.

SECTION 11Variables that belong in the method statement

The A5.13 annex names three characteristics that SMAW variables affect: dilution, deposition rate and deposit thickness. A method statement that records only the classification and the amperage leaves the other two undocumented.

No single value here is a universal instruction. Where published sources disagree, the page shows the spread rather than printing one number as if it applied everywhere.

SECTION 12What classification testing establishes — and the EN 14700 difference

Under AWS A5.13, the classification requirement is chemical analysis of the deposited weld metal (or, for tungsten carbide electrodes, the granule mesh range, quantity and composition). The published contents of the 2000 and 2010 editions place chemical analysis in Part B alongside the summary of tests, retest and weld test assembly; hardness appears in an informative annex as approximate values. Tensile strength, impact energy and wear rate are not classification tests for these electrodes.

Under EN 14700, public abstracts describe a different construction: product-form letters (E covered electrode, T cored wire/rod, P powder), alloy groups built on Fe, Ni and Co matrices, and hardness grading codes embedded in the designation (for example a 300 band of 275–325 HB and a 60 band of 57–62 HRC). Chemical analysis is referenced to EN ISO 6847 and hardness testing to the EN ISO 6506 / 6508 series.

A single order line should name one governing system. The other can be noted as comparable, not equivalent. If a project needs both chemistry and a hardness band verified by test, write the hardness requirement as a separate supplementary clause with its own method. There is no official AWS↔EN 14700↔GB/T 984↔DIN 8555 conversion table; datasheets printing several codes commonly add ~ or "nearest classification", as Lincoln Electric's public hardfacing listings show. Treat those rows as manufacturer-stated approximate pairings.

EN 14700 details here come from third-party public abstracts, not the official text. Verify hardness bands, alloy-group count and referenced test standards against the formal edition, or keep the comparison qualitative.

SECTION 13The specification line, the batch file and the goods-in check

A certificate of conformance typically states typical or specification values; a lot-specific report gives measured values tied to the lot or heat number on the carton. Where a project asks for EN 10204 3.1 or a similar document type, name the test list separately: the document type defines who signs the declaration, not which tests were run. AWS A5.01 procurement guidance is a separate document family for lot classification and test schedules; reference it only if the project invokes it.

Marking clause numbers differ between editions; verify the applicable clause in the named edition before quoting a number on the live page.