Structural steel fabrication is quoted differently from a single machined part, and shops that treat it the same way lose money on both ends. A staircase, a frame, a set of brackets, or a welded base plate is not one operation — it is raw profile and plate priced by weight, cutting and drilling, welding, surface treatment, assembly, and often transport and erection on top. Build a metal fabrication quote by lumping all of that into "say eight hours plus material" and you will either scare the customer off or eat the difference yourself. This guide walks through every cost line in a structural steel job, with the euro figures and rules of thumb an Italian conto-terzi carpentry shop actually uses.

The goal is a quote you can defend line by line: how much steel goes into the part, what you pay to cut, drill, and weld it, what the finishing and assembly add, and where your margin sits. Get those right and pricing a weldment stops being a gut call.

Start with material by weight

Structural steel is bought and sold by the kilogram, so the material line starts with weight, not with a part count. Take the cut list from the drawing — every beam, channel, angle, plate, and tube — and multiply each length by its linear weight (kg/m for profiles, or thickness × area × 7.85 g/cm³ for plate). Sum it and you have the net theoretical weight.

Then add what you actually pay for:

• Scrap and offcuts. You never buy the exact net weight. Bar and profile offcuts, plate nesting waste, and saw kerf push purchased weight 8–20% above net, depending on how standard your lengths are.
• Material grade. S235 and S355 carbon steel are the common structural grades; stainless (304/316) costs several times more per kilogram and is slower to work. Price from your current supplier sheet, not last quarter's.
• Certification. Mill certificates (3.1 / 3.2 EN 10204) and CE marking under EN 1090 carry real cost and paperwork on structural work — budget for them when the job calls for it.

A clean way to express it: purchased weight = net weight × (1 + waste factor), then material cost = purchased weight × €/kg. Keep the waste factor per family of parts so it reflects how you actually buy.

Cutting, drilling, and prep

Once the steel is on the floor, the first labour line is turning stock into parts. How you cut drives both speed and edge quality:

• Sawing — bandsaw or cold saw for profiles. Cheap and clean, but slow on thick sections.
• Plasma and oxy-fuel — fast on plate, leaves dross and a heat-affected edge that often needs grinding.
• Laser — clean, accurate, and fast on thinner plate; see laser cutting cost calculation for how to price the machine time properly.

Drilling, punching, tapping, countersinking, bevelling for weld prep, and deburring all sit here too. The honest way to estimate this is by your machine and labour rates per operation — if you have not nailed those down, how to calculate your machine shop hourly rate is the place to start, because every other number on the quote rides on a defensible hourly figure.

Welding is its own cost centre

Welding is where fabrication quotes quietly go wrong. A fillet weld is one line on a drawing, but behind it sit joint geometry, plate thickness, number of passes, prep, position, and the cleanup nobody bills. Weld cost is driven by the volume of deposited metal — which scales with the square of the fillet leg — divided by your process deposition rate, then divided again by a realistic operating factor of 20–40% to get billable welder time.

Do not fold welding into a vague labour bucket. Estimate deposited weight, arc time, prep, fit-up, and finishing as separate lines. The full method — deposition rates, operating factor, consumables, distortion control — is laid out in the welding and fabrication cost estimation guide. For a structural weldment, welding plus its prep and cleanup is frequently the single largest labour block on the sheet.

Surface treatment, assembly, and erection

These three lines are where hand-written quotes lose the most margin, because they happen after the "real" work and get waved through.

Surface treatment. Structural steel almost always needs protection: shot blasting to Sa 2.5, primer, top coat, hot-dip galvanising, or powder coating. Galvanising is usually priced per kilogram by the bath; paint systems are priced per square metre of surface area. Both depend on the geometry, not just the weight, so estimate the coated area from the drawing.

Assembly and fit-up. On a multi-part weldment, jigging, clamping, squaring, and tacking can rival the welding itself. Heavy parts need repositioning, flipping, and crane time. Name these as explicit lines — if you do not name them, you will not price them.

Transport and erection. If the job ships and gets installed on site, oversized loads, craneage, site labour, and travel are real euros that belong on the quote, not in a goodwill discount.

Worked example: a small steel frame

Put the lines together on a simple welded frame — S275 profile and plate, painted, delivered locally.

Cost line	Basis	Amount
Material (steel)	180 kg net × 1.12 waste × €1.20/kg	€242
Sawing & drilling	3.0 h × €55/h	€165
Welding + prep	5.5 h × €60/h	€330
Blast + 2-coat paint	9 m² × €18/m²	€162
Assembly & fit-up	2.5 h × €55/h	€138
Transport (local)	flat	€90
Subtotal (cost)		€1,127
Margin @ 25%	markup on cost	€282
Quoted price		€1,409

The numbers are illustrative — plug in your own rates — but the structure is the point: every line is traceable, so when the buyer pushes back on price you can show exactly what sits behind it.

Margin: get the maths right

That last row hides the most common pricing error in the trade. Adding "25%" can mean two completely different things. A 25% markup on €1,127 of cost gives €1,409 and a margin of about 20%. A true 25% margin means cost is 75% of price, so the price is €1,127 ⁄ 0.75 = €1,503. Confusing the two quietly bleeds points off every job. If that distinction is fuzzy, read margin vs markup in manufacturing pricing before you set your default — it is the cheapest profit you will ever recover.

Decide which one your quoting follows and apply it consistently. Also make sure the quote document itself is complete: validity period, lead time, payment terms, exclusions, and what is and isn't included. The manufacturing quote template checklist covers everything a structural quote should state in writing.

Let the drawing do the quoting

The slowest part of any structural fabrication quote is reading the drawing: building the cut list, summing the steel weight, finding every weld symbol and its size, and pulling the coated area and finishing notes. Do it by hand on a busy assembly drawing and an afternoon disappears — and one missed weld or wrong profile weight throws the whole price off.

This is exactly what QuoteBuddy is built for. You upload the technical drawing, the AI interprets the geometry — profiles, plates, holes, weld callouts, materials — and your own deterministic rules apply the €/kg material cost, machine and welder hourly rates, finishing rates, and markup the same way every time. The AI does the reading; your rules do the pricing, so two estimators quoting the same weldment land on the same defensible number. You go from RFQ to a branded quote PDF in minutes instead of an afternoon.

See the plans and pricing to start a 30-day free trial, and quote your next structural job straight from the drawing.