Weld Consumables & Gas

Estimate wire, rods, gas, arc time and cost from the joint size and length

Process

Material being welded

Sets the density the weld metal is weighed at. Aluminium weld metal is about a third the mass of steel for the same joint.

Filler

Names the item on your shopping list. Pick the size you actually run — it has to suit the process above.

Joint

Fillet leg length (z)

A 6mm leg is about 0.16 kg of weld metal per metre in steel.

Length of weld per joint

Total run length. A 6m beam welded both sides is 12m.

Number of joints like this

Reading 1

Results

MIG 1.0mm solid wire to buy

1.64kg

Weld metal

1.55kg

Shielding gas

0.64m³

Arc time

0.62h

Joint6mm leg fillet

Weld metal cross-section19.8 mm² → 0.155 kg per metre of weld in mild / carbon steel (7850 kg/m³)

Length of weld10 m × 1 joint = 10 m

Deposition efficiency95% for MIG / MAG solid wire — Typical estimating efficiency (trade-published); actual results vary, the rest goes in spatter and stick-out; follow your consumable data sheet

Filler to buy1.55 kg weld metal ÷ 95% = 1.64 kg

Arc time1.55 kg deposited at 2.5 kg/h (typical: inside the ESAB OK Autrod 12.51 data sheet range (1.0 mm: 1.0–5.5 kg/h) — follow your consumable data sheet) = 0.62 h at the arc

Time on the job2.1 h at 30% arc-on time (fit-up, grinding, moving) — workshop estimate, adjust to suit

GasArgon / CO₂ mix (ISO 14175 M20 / M21; typical — gas makers' selection guidance (BOC shielding gas brochure); follow your gas supplier's data sheet) at 15 L/min (typical: BOC shielding gas brochure (~15 L/min) — set from your gas supplier's data sheet) × 37 min + 15% for pre-flow, post-flow and stop-starts (a fixed estimating assumption, not a safety allowance or a standards requirement) = 643 L (0.64 m³)

Fit-upA geometric estimate of a clean preparation (10% convexity allowance — workshop estimate, adjust to suit, as the published fillet tables use). Over-welding, poor fit-up and repairs all add to it.

What to buy — 4 items

MIG 1.0mm solid wire

1.64 kg needed — common pack size, adjust to suit

1 × 15 kg

Argon CO2 welding gas

643 litres — set a cylinder size for a bottle count

1 × 0.64 m³

MIG contact tips

Reminder — not calculated

Anti-spatter spray

Reminder — not calculated

Opens at Screwfix, Toolstation and the merchants for your trade. Free account, no card.

Indicative design aids — every figure and its source is listed under "Figures based on" below.

A materials, time and cost estimate. It does not establish weld acceptance, qualify a welding procedure or demonstrate regulatory compliance.

Figures based on

Weld metal density: BS EN 1993-1-1:2005 §3.2.6 (carbon steel), BS EN 10088-1:2023 (stainless), BS EN 1999-1-1:2007 §3.2.5 (aluminium)
Weld metal volume: Geometry — fillet z²/2; butt root gap × thickness + the bevel triangle d² tan(α/2) + a parabolic cap; a square butt needs a root gap
Butt cap height: No source — workshop figure, not ISO 5817: a flat 1.5 mm reinforcement, a fixed estimating assumption for the weld metal volume. Not a weld acceptance limit and not a standards requirement (BS EN ISO 5817 limits excess weld metal by quality level; check the limit for your level in the standard). Not an input; the WPS sets the real cap
Fillet convexity allowance: No source — workshop estimate, adjust to suit: 10%, the allowance the published fillet tables use (TWI Job Knowledge 96); an input
Deposition efficiency: Typical — MMA 70% from the ESAB OK 48.00 data sheet; MIG/MAG 95%, flux-cored 87%, TIG / SAW / plasma 99% are typical estimating efficiencies, trade-published (The Fabricator), no manufacturer sheet retrieved; actual results vary. Carbon-steel figures and provisional estimating defaults, not values any standard requires. An input: put in the figure from your consumable data sheet or your own measured one
Deposition rate: Typical — MMA from the ESAB OK 48.00 data sheet, MIG inside the ESAB OK Autrod 12.51 data sheet range, SAW from Lincoln Electric guidance; flux-cored 3.5, TIG and plasma 0.6 kg/h are workshop estimates with no sheet retrieved, adjust to suit. Carbon-steel figures, scaled by density for another material. Follow your consumable data sheet
Shielding gas flow: Typical — BOC shielding gas brochure (MIG/MAG ~15 L/min), EWM shielding-gas guide (TIG 5–10 L/min); plasma 8 L/min is a workshop estimate taken from TIG, no sheet retrieved, adjust to suit. Set from your gas supplier's data sheet
Shielding gas groups: BS EN ISO 14175:2008 (I1 argon, I3 argon/helium, M12 / M13 low-oxidising argon mixes, M20 / M21 argon/CO₂, C1 CO₂)
Which gas is typical for which process and metal: Typical — gas makers' selection guidance (BOC shielding gas brochure): tungsten torches and aluminium inert gas, carbon-steel MAG the active mix, stainless MIG a low-oxidising mix, stainless flux-cored M21. Follow your gas supplier's data sheet
Stainless filler grade (308L for 304, 316L for 316): Typical — consumable makers' selection charts (ESAB). Follow your consumable data sheet
Process numbers: BS EN ISO 4063:2023 (114 is self-shielded flux-cored)
Gas allowance 15%: No source — workshop estimate: +15% gas for pre-flow, post-flow and stop-starts. A fixed estimating assumption, not an input, and not a safety allowance or a standards requirement; the gas line shows it so the order can be audited back to it
Arc-on time 30%: No source — workshop estimate, adjust to suit: the share of the shift actually at the arc. An input
Pack sizes: No source — common pack size, adjust to suit: 5 kg electrodes, 15 kg steel wire, 7 kg aluminium wire, 25 kg SAW wire. An input; set what your supplier sells

Indicative design aids. "Typical" means no current standard sets it: follow your WPS and the consumable or gas data sheet named. "No source" means a workshop estimate: adjust to suit, or, where the box says it is fixed, a fixed estimating assumption.