AWS A2.4 §15 · Hardfacing / Buildup / Cladding

Surfacing Weld Symbol

How to read the surfacing weld symbol — the wavy line (three arcs) that always goes below the reference line. Hardfacing, buildup, cladding, and D1.1 repair applications.

Surfacing Weld Symbol — Anatomy
always below ref line
Basic surfacing symbol
3/16 thickness to the left
3/16" buildup thickness
extent shown on drawing
Partial extent on drawing
Arrow-side only: The surfacing symbol is ALWAYS below the reference line. There is no other-side surfacing — the arrow points to the surface receiving the deposit. This is one of the few weld symbols with no other-side option.

Surfacing Weld Symbol Dimensions

Per AWS A2.4 §15, surfacing deposits weld metal on a surface — not between two members. It is the only common weld symbol that never appears above the reference line.

Buildup Thickness

Shown to the LEFT of the symbol. When omitted, thickness is not critical — the deposited amount is at the welder's discretion per the WPS.

Extent

When the surfacing covers only part of the surface, the extent is shown on the drawing with dimension lines or hatching. The symbol itself does not carry length or width dimensions.

Multiple Layers

Multiple reference lines can specify multiple surfacing layers, each with its own thickness. The first reference line (closest to the arrow) is welded first.

Not a joining weld: Surfacing deposits metal on one surface. It does not join two members. If you need to fill a gap between members, that is a groove or plug weld, not surfacing.

Surfacing Weld Types

Application Purpose Common Processes
Hardfacing Wear resistance on contact surfaces SMAW, FCAW with hardfacing wire
Buildup Restore worn dimensions SMAW, GMAW, SAW
Cladding Corrosion resistance layer SAW, ESW with stainless/Inconel
Dimensional correction Correct fit-up during assembly Per A2.4 §15.5
D1.1 repair Repair buildups per §7.25 Same WPS as original weld

Surfacing Weld Symbol FAQ

What is a surfacing weld symbol?
A surfacing weld symbol is a series of small arcs (a wavy line or three humps) placed BELOW the reference line only. It indicates weld metal deposited on a surface — not a joint. Surfacing is used for hardfacing (wear resistance), buildup (restore dimensions), cladding (corrosion resistance), and dimensional correction. It is always arrow-side only — no other-side significance.
Why is the surfacing symbol always below the reference line?
Per AWS A2.4 §15, the surfacing symbol has arrow-side significance only. It is always placed below the reference line because surfacing deposits weld metal on one surface — the surface the arrow points to. There is no concept of 'other side' because surfacing is not a joint between two members. The arrow simply indicates which surface receives the deposit.
What is the difference between surfacing and a regular weld?
A surfacing weld deposits metal on a single surface to obtain desired properties or dimensions. It is NOT a joining weld — it does not connect two members. Regular weld symbols (fillet, groove, plug, etc.) join members together. Surfacing applications include hardfacing for wear resistance, buildup to restore worn dimensions, cladding for corrosion resistance, and dimensional correction during assembly.
Does D1.1 cover surfacing welds?
D1.1 §7.25 governs repair buildups, which use surfacing techniques. The same WPS and inspection requirements apply to surfacing buildups as to the original welds. However, hardfacing and cladding for wear or corrosion resistance are specialized applications typically outside D1.1 structural scope. When surfacing is used for dimensional correction on structural members, D1.1 workmanship requirements apply.