Every steel takeoff is Σ (kg/m of the section × length × count). The section's mass per metre is in its designation — W410×60 is 60 kg/m, HSS sizes convert via mass tables — so no guessing on weight. What you have to find is the count and the length of each member.
One thing worth stating plainly: W-beams, columns and other rolled sections are structural steel, taken off as tonnage. They are not reinforcing and never belong in the rebar number — that's a weight-by-bar-size line for a different material.
Where there's a steel/beam schedule, the takeoff is straightforward — marks, counts and lengths in one table. Where members are labelled on the framing plans only, you count every labelled member and assign each a length, and that's where steel gets under-read: a plan can carry hundreds of member labels and a quick read grabs a fraction. Don't stop early, and don't blindly de-duplicate — the same section legitimately recurs at different spans.
The section weight is certain; the member length is not. With no schedule, lengths come from the dimensions where shown, otherwise from typical bay spans or scaling. This is the judgment call in a steel takeoff — the tonnage is only as good as the lengths behind it.
Give Me The Cost reads the framing plans and schedules, pulls the section marks and counts, and computes tonnage from the kg/m in each mark with a connections allowance — keeping W-beams in structural steel, never in rebar. Its confidence read is honest about where lengths were dimensioned versus estimated from bay spacing, so on a no-schedule set you know exactly what to double-check.
How is structural steel measured in a takeoff?
By weight, in tonnes. The mass per metre is in the section name (W250×67 = 67 kg/m), so tonnage is kg/m × length × count, plus a connections allowance.
Are W-beams counted as steel or rebar?
Structural steel. W-beams and rolled sections are taken off as tonnage in the steel line — they are never counted as reinforcing (rebar), which is a separate weight-by-bar-size material.
Why is plan-based steel under-read?
When members are labelled on framing plans with no schedule, a plan can carry hundreds of labels. A quick read captures only a fraction, so the tonnage comes in low unless every member is counted.
Where do member lengths come from with no schedule?
From the dimensions where shown, otherwise typical bay spans or scaling off the plan. Lengths are the judgment call — the section weight is certain, the length is estimated.