Manual metal arc (MMA / stick)
The covered electrode supplies its own shielding, so the process tolerates wind and outdoor site conditions that would displace a gas shield.
Indicative
Welding
Welding for steel: processes, weldability, and the three certificates buyers confuse
Welding is joining steel as a service — you supply the requirement, a certified shop supplies the qualified weld. This page covers what actually decides the outcome: which process suits your joint and material, what carbon equivalent tells you about weldability, what a provider needs from you before quoting, and — because this is where welding buyers get confused — why the material's certificate, the shop's certification and the welder's qualification are three separate documents, not one.
What drives the price
- Material thickness
- Steel grade and weldability
- Joint type and welding position
- Weld length and volume
- Inspection and NDT requirement
- Certification requirement
What to send for a quote
- Grade or material number
- A drawing with joint details
- Material thickness and form
- Weld length or seam count
- Welding position and access
- Whether you need inspection or NDT
- Execution class or certificate requirement, if structural
- Delivery address and required date
Which process for which job
MAG, solid wire
Continuous wire feed gives a higher deposition rate than a stick electrode, suiting shop production runs.
Indicative
TIG
Independent heat and filler control suits thin material and root passes where weld appearance and quality matter most.
Indicative
Submerged arc welding (SAW)
High deposition under a flux blanket suits long, straight seams in thick plate.
Indicative
Weldability and carbon equivalent
Carbon equivalent is one indicator among several — it tells you how the chemistry behaves under welding heat, not a pass/fail number on its own. The qualified WPS for your grade and thickness is what actually sets the procedure.
Standard-defined
Execution classes for structural steel
EN 1090-2
- EXC1
- EXC2
- EXC3
- EXC4
Standard-defined
Welding quality requirements
EN ISO 3834
| 3834-2 | Comprehensive quality requirements | ||
|---|---|---|---|
| 3834-3 | Standard quality requirements | ||
| 3834-4 | Elementary quality requirements |
Standard-defined
Welder qualification
EN ISO 9606-1
Standard-defined
Welding procedures — WPS and WPQR
- EN ISO 15609-1
- EN ISO 15614-1
Standard-defined
Services
Will the weld cause distortion, and how tight a tolerance can you hold?
There is no general figure for how much a weld will distort a part or what tolerance the finished assembly can hold — it depends on joint design, restraint, welding sequence and heat input, all of which are job-specific. If you have a tolerance requirement, say so on the enquiry; the shop should design the sequence (and any pre-set or clamping) around it rather than quoting a number that doesn't apply to your geometry.
What information do you need for a quote?
Send the grade or material number, a drawing showing the joint details, the material thickness and form, the weld length or seam count, the welding position and access, and whether you need inspection or NDT. If the job is structural, add the required execution class or certificate requirement. Those eight things turn an enquiry into a firm price rather than a range.
Can I send my own material to be welded?
Supplying your own material for welding is common practice, but acceptance — and the terms around liability, weld-procedure suitability for that exact grade, and traceability — varies by provider. Ask before shipping, and if the material carries an EN 10204 certificate, ask how the shop will preserve that traceability through the weld.
Do I get an EN 10204 3.1 certificate for the material?
EN 10204 defines the material's inspection-document types — 2.1, 2.2, 3.1 and 3.2 — and welding the material doesn't change that certificate; it belongs to the base metal, same as it would for a cut piece. 3.1 is the usual buyer default in steel procurement. This is separate from whether the shop or the welder is certified — see the next two questions.
Is your shop EN 1090 / EN ISO 3834 certified?
This is the layer most sawing- or cutting-service pages never mention. EN 1090 requires CE marking of structural steel components placed on the EU market, issued against an execution class (EXC1 to EXC4, defined in EN 1090-2) that reflects how demanding the structure is. Separately, EN ISO 3834 certifies the shop's welding quality management system, in tiers from elementary to comprehensive. Ask which execution class the shop is certified to, not just whether they 'do EN 1090' — a shop certified for EXC2 is not automatically qualified for EXC3 or EXC4 work.
Are your welders individually qualified?
A shop's EN 1090 / EN ISO 3834 certification is not the same as an individual welder being qualified for your joint. EN ISO 9606-1 qualifies a welder for a tested range of process, material group, thickness and position — a certified shop can still assign a joint outside a particular welder's tested range. Ask which qualification range covers your specific joint. Qualifications also require periodic revalidation under EN ISO 9606-1; we haven't verified the exact interval against the current standard text, so ask the shop for their current renewal record rather than assuming a figure.
MMA, MAG, TIG or submerged arc — which process is right for my job?
Manual metal arc (MMA/stick, EN ISO 4063 reference 111) needs no shielding gas, which is why it holds up on site work and outdoor repairs. MAG with solid wire (135) feeds continuously, giving a higher deposition rate that suits shop production runs. TIG (141) gives the most precise heat and filler control, which is why it's chosen for thin sections and root passes where quality matters most. Submerged arc welding (SAW, 121) runs under a flux blanket at high deposition, suited to long straight seams in thick plate. The right choice depends on your material, joint and volume — ask the shop which process their qualified WPS covers for your grade.
How do you know if my steel grade is weldable?
Carbon equivalent is the standard starting point. The IIW formula — CEV = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15, from EN 1011-2 Annex C method A, best suited to C-Mn and low-alloy steels above roughly 0.18% carbon — tells you how the chemistry is likely to behave under welding heat. It is one indicator among several, not a pass/fail number by itself, and other formulas (CET, Pcm) apply to different composition windows. What actually governs the job is a qualified WPS for your grade and thickness — ask the shop whether one exists or needs qualifying under EN ISO 15614-1.
What is a WPS, and do I need to see one?
A Welding Procedure Specification (WPS) documents how a joint is to be welded — process, consumables, parameters, sequence — to the content set out in EN ISO 15609-1. Before it can be used, the procedure is tested and the result recorded as a Welding Procedure Qualification Record (WPQR) under EN ISO 15614-1. For anything beyond a simple repair, ask to see the WPS for your grade and joint type — it's the document that actually governs the weld, more specific than any general weldability guidance.
Is there a minimum order quantity?
There is no industry-wide minimum order quantity for contract welding; it varies by provider and by whether a new WPS needs qualifying for your grade and joint. Ask as part of your enquiry rather than assuming.
What is the lead time?
No general lead time can be stated honestly — it depends on whether a qualified WPS already exists for your grade and joint, the inspection or NDT scope, and the shop's current load. If a new procedure needs qualifying under EN ISO 15614-1, that adds time before production welding can start. Ask for a committed date with your quote.
What does contract welding cost?
Contract welding is not priced from a single rate, so any figure quoted here would mislead. What drives it is material thickness, steel grade and its weldability, joint type and welding position, total weld length or volume, any inspection or NDT requirement, and whether certification (execution class, welder qualification) applies. Send the eight items in the quote checklist and you will get a firm price instead of a range.