Schedules, cutting and pricing
Bending schedule total tonnage by bar size
- where
- total length of bar (m)
- total length of each bar size from the schedule (m)
- total mass (kg)
- tonnage to order (t)
- allowance for offcuts (%)
Explain this equation
Adds up a bar bending schedule into total length, total mass and tonnage to order, from the total length of each bar size.
L6 to L40 are the total lengths of each bar size: for each bar mark, the number of bars times the cutting length, added up by size. Lt is the grand total length, M the total mass, w an allowance for offcuts and Mo the tonnage to order.
Each size is weighed at its own mass per metre, d²/162, because mass grows with the square of the diameter; averaging sizes would be wrong. The 1000 converts kilograms to tonnes, and the allowance multiplies up the total for cutting from stock.
Sense check: about 1126 m of 12 mm bar, or 94 bars of 12 m, make a tonne. A 16 mm bar weighs nearly twice as much per metre as a 12 mm bar.
Watch out: bar supplied cut and bent is normally charged on the scheduled weight, so leave the allowance at zero for that.
Adds up a bar bending schedule into total weight and tonnage, from the total length of each bar size (number of bars × cutting length for every bar mark).
Enter your values to see the result.
Good to know
For each bar mark, multiply the number of members by the bars per member and the cutting length to get a length, then add the lengths up by size. Each size is weighed at d²/162 kg/m. Bar supplied cut and bent to schedule is usually priced on the scheduled weight, so leave the allowance at 0; add an allowance when you cut from stock lengths. As a check, 1 t of 12 mm is about 1126 m, or 94 bars of 12 m.
Common mistake
Adding up the number of bars instead of their lengths, or weighing every size at one average mass per metre.
Limits
Nominal masses. The supplier’s weighbridge or schedule weight may differ slightly within the BS 4449 mass tolerance.
Sources
- BS 8666:2020 Scheduling, dimensioning, cutting and bending of steel reinforcement for concrete. Specification (Table 2 minimum radii and end projections; Table 5 standard shapes and length formulae)
- BS 4449:2005+A3:2016 Steel for the reinforcement of concrete. Weldable reinforcing steel. Bar, coil and decoiled product
- CR Steel, Steel calculator sheet (bar mass per metre, metres per tonne, 12 m bars per tonne; BS 4483 mesh masses: A142 2.22, A193 3.02, A252 3.95, A393 6.16 kg/m²)
Results are calculations from the published methods and figures shown, and depend on the data you enter. Always work to the engineer’s drawings and bending schedules, BS 8666, BS EN 1992, BS EN 1090-2, BS 5531/the BCSA National Structural Steelwork Specification and manufacturers’ data. Lifting must be planned under LOLER by a competent person.