steel-sections

Weights, dimensions and section properties of standard steel sections, plus weight formulas for plate, bar and tube. Pure Python, no dependencies, data bundled.

pip install steel-sections

import steel_sections as ss

ss.get("ISMB 200").mass_kg_m        # 24.17
ss.get("ismb200").mass_1964_kg_m    # 25.4  (the old handbook value many charts still print)
ss.get("IPE 300").iy_cm4            # 8356.0
ss.get("ISA 50x50x5").mass_kg_m     # 3.79

[s.section for s in ss.series("HEA")][:3]   # ['HEA 100', 'HEA 120', 'HEA 140']

ss.rebar(12).weight_kg_m            # 0.888
ss.rebar("#5").weight_lb_ft         # 1.043
ss.pipe("2", "40").weight_lb_ft     # 3.66
ss.gauge(16).mm                     # 1.519

# formulas: dimensions in mm, kg per metre (plate: kg per piece); density defaults to 7850 kg/m³
ss.round_bar(12) * 12               # 10.65 kg for a 12 m bar
ss.flat_bar(50, 6)                  # 2.355
ss.round_tube(60.3, 3.91)           # 5.44
ss.plate(2500, 1250, 10)            # 245.3 kg
ss.round_bar(20, density=2700)      # aluminum

Command line:

$ steel-sections ISMB 200
$ steel-sections --series ISMC
$ steel-sections --rebar 16
$ steel-sections --pipe 1-1/2 80
$ steel-sections --gauge 14

MCP server for AI assistants

The package includes a Model Context Protocol server, so Claude, Cursor, VS Code and other MCP clients can look up sections and calculate weights. It has no dependencies and talks over stdio.

{
  "mcpServers": {
    "steel-sections": {
      "command": "uvx",
      "args": ["--from", "steel-sections", "steel-sections-mcp"]
    }
  }
}

With the package installed (pip install steel-sections), the command can also be just steel-sections-mcp.

Tools: get_section (IS 808 and EN sections with all properties), list_series, pipe (NPS and schedule), rebar (US bar sizes and metric diameters), sheet_gauge, and shape_weight (plate, flat, round, square and hex bar, round and rectangular tube, angle; any density). Every result carries a reference to the matching weight chart.

What is included

Every section row was checked against the source: mass against 0.785 × area, radius of gyration against √(I/A), elastic modulus against I/(D/2). Misprints in the printed IS 808 tables are corrected. Section attributes keep the CSV column names, with units in the name (mass_kg_m, ix_cm4, depth_mm). European sections use EN axis names (y-y major, z-z minor). American W, S, C, MC, L and HSS shapes are not included: the AISC Shapes Database has no redistribution licence.

Values are theoretical (7850 kg/m³). Check them against the current standard or the mill certificate before design or purchase. Interactive version with drawings, charts and a calculator: steelweight-calculator.com.

Licence

Code: MIT. Data: Indian sections CC BY 4.0 (values from IS 808 as made public by Public.Resource.Org); European sections Apache-2.0 (geometry from the fib-international structuralcodes library); pipe, rebar and sheet gauge tables CC BY-SA 4.0 (adapted from the Wikipedia articles Nominal Pipe Size, Rebar and Sheet metal). See DATA-LICENSE.md.