Build a practical bill of materials for steel structures including beams, columns, plates, gussets, bolts, brackets and accessories.
Add each distinct component as a BOM line. Use quantity for repeated beams, plates, bolts, gussets or accessories.
| Item | Component | Qty | Length | Dimension A | Dimension B | Thickness | Unit Weight |
|---|
| Component | Calculation | Typical Use |
|---|---|---|
| Beam / Column | Length × section unit weight | Primary structural members |
| Channel | Length × section unit weight | Frames, supports and secondary members |
| Angle | Length × section unit weight | Bracing and connections |
| Round Bar | Diameter × length × density | Pins, rods and miscellaneous steel |
| Plate | Length × width × thickness × density | Base plates, connection plates and stiffeners |
| Gusset Plate | Length × width × thickness × density | Brace and connection nodes |
| Flat Bar | Length × width × thickness × density | Straps, cleats and brackets |
| Bracket | Plate geometry or unit weight | Supports and connections |
| Anchor Bolt | Quantity × unit weight | Base connections |
| Bolt Set | Quantity × unit weight | Structural bolted connections |
| Nut / Washer | Quantity × unit weight | Connection hardware |
| Accessory | Quantity × unit weight | Miscellaneous components |
A bill of materials converts the structural design into identifiable material line items. Each line represents a component that must be fabricated, purchased or supplied.
For rolled steel sections such as beams, channels and angles, the easiest method is to enter the manufacturer's section weight per unit length.
For plates and simple solid sections, the calculator determines volume from the entered dimensions and multiplies it by steel density.
Bolts and accessories are handled using quantity and unit weight, allowing hardware to remain separate from the main structural steel tonnage.
Structural beams and columns are normally specified by a standard section designation and a mass per unit length. Examples include I-sections, H-sections, channels and angles.
Instead of attempting to reconstruct every rolled profile from basic dimensions, enter the manufacturer's or section-table unit weight in the Unit Weight field. This produces a more reliable BOM weight than a simplified geometric approximation.
Plates and gussets can be calculated from their rectangular dimensions and thickness. If the actual plate is irregular, use the appropriate net area or use a conservative purchasing dimension.
For fabrication purchasing, plate nesting and cutting waste can materially affect the amount of stock plate required. The steel waste percentage provides an overall allowance but does not perform plate nesting.
Bolts, nuts and washers should normally remain separate BOM items rather than being hidden inside the structural steel weight.
This makes procurement easier because the BOM can identify the required hardware quantities independently of the steel members.
The waste allowance is intended to cover estimating losses associated with cutting, trimming and fabrication.
For example, if the calculated net structural steel requirement is 10,000 kg and a 5% allowance is entered:
Actual purchasing quantities should be based on the cutting and nesting plan where material cost is significant.
What can be included in a steel structure BOM?
Beams, columns, channels, angles, plates, gussets, stiffeners, brackets, bolts, nuts, washers, anchor bolts and other accessories can all be included.
How should I enter a beam?
Select Beam / Column, enter its quantity and length, then enter the manufacturer's section mass per metre in the Unit Weight field.
How are plates calculated?
Plate weight is calculated from length, width, thickness and steel density.
Can gusset plates be included?
Yes. Gussets are handled as individual plate-type BOM components.
Can bolts be counted separately?
Yes. Bolt quantities are tracked separately from structural steel pieces.
Does the calculator include steel waste?
Yes. A project-level waste percentage can be applied to the calculated structural steel weight.
Does this calculate the required beam size?
No. Beam sizing requires structural analysis and design calculations. This tool only organizes and estimates quantities for already specified components.
Can accessories have their own unit weight?
Yes. Any miscellaneous item can be entered with quantity and unit weight.