40mm Rebar Weight per Metre (and per Bar)

40mm Rebar Weight per Metre — Key Figures

The unit weight of 40 mm reinforcing steel bar is 9.872 kg/m. This is the highest weight-per-metre of any diameter routinely stocked for standard structural work, reflecting the 40 mm bar’s large cross-section of 1,256.6 mm². At a standard 12-metre stock length, a single bar weighs approximately 118.5 kg — meaning mechanical handling equipment is effectively mandatory on site.

Deriving the 40mm Weight Figure

The standard formula for rebar unit weight is:

kg/m = d(mm)² × 0.00617

The constant 0.00617 is derived from steel density (7,850 kg/m³) and the circular cross-section geometry. For 40 mm:

• d² = 40² = 1,600
• 1,600 × 0.00617 = 9.872 kg/m

Cross-check via first principles: cross-section area A = π/4 × 40² = 1,256.6 mm² = 12.566 cm². Volume per metre = 12.566 cm² × 100 cm = 1,256.6 cm³. At 7.85 g/cm³: 1,256.6 × 7.85 = 9,864 g = 9.864 kg/m — rounding differences from π and density variation account for the minor discrepancy; the formula value of 9.872 kg/m is the conventional figure used in bar schedules and Mill Test Certificates.

Weight per Bar at Different Stock Lengths

40 mm bars are available in multiple stock lengths. The weight per bar scales directly:

The metres-per-tonne figure (≈ 101 m) remains constant because it is purely a function of unit weight. The practical implication: a structural engineer specifying 200 m of T40 bars requires approximately 1.97 tonnes of steel (200 ÷ 101).

Comparing 40mm Against the Full Heavy-Bar Range

Procurement teams evaluating large-diameter bars benefit from a comparison across the heavy end of the range:

The jump from 32 mm to 40 mm represents a 56% increase in cross-sectional area and unit weight. This is why 40 mm is reserved for the most heavily loaded structural elements — see our companion article on 40mm rebar uses for application-level detail. For the complete diameter range, consult the rebar weight chart.

Logistics Considerations for 40mm Rebar

The weight of 40 mm bars has direct logistics implications that buyers should plan for:

• Crane capacity: At 118.5 kg per 12 m bar, a 10-bar lift weighs ~1.2 tonnes. Standard construction cranes handle this, but lift plans should be reviewed by a lifting engineer.
• Bundle weights: Standard export bundles are assembled to approximately 2 tonnes. At ~8 bars/tonne in 12 m, a 2-tonne bundle contains roughly 16 bars.
• Container loading: 40 mm bars in 12 m lengths load into 40-foot containers; 20-foot containers require bars no longer than ~5.9 m or end-loaded with specialist frames. Maximum container payload (~28 t) accommodates approximately 235 bars at 12 m.
• Cut-and-bend: Bending 40 mm bars requires heavy-duty mandrels; not all fabrication shops carry 40 mm tooling. Confirm cut-and-bend capability before ordering bar schedules.

Ordering 40mm B500B from Steel Rebar Germany

Steel Rebar Germany supplies 40 mm B500B hot-rolled deformed rebar to EN 10080 and DIN 488, available in standard stock lengths and custom lengths. Every shipment includes an EN 10204 3.1 Mill Test Certificate, Certificate of Origin, and CE Declaration of Performance. We handle export packaging and documentation for worldwide destinations. Request a quote with tonnage, lengths, and destination port.