How do I calculate the carbon footprint of a spanner or other hand tool?

Take the steel bar per tool, including flash and scale lost in forging, and multiply by the steel supplier's per-kg figure. Add forging furnace fuel, heat treatment, machining and plating electricity, then divide by tools passed.

Steel and forging

• Alloy steel bar by weight per tool, including flash.
• Forging furnace fuel or induction heater electricity.
• Trimming presses and shot blasting.

Finishing

• Hardening and tempering furnaces.
• Grinding, polishing and chrome or nickel plating.
• Blister cards, rolls and cartons.

Per piece

Report per tool with its weight. Group tools by weight band rather than one average across a whole catalogue.

Worked example: spanner and hand tool unit per piece (one month)

• Electricity: 45,000 kWh x 0.710 = 31,950 kg CO2
• PNG: 6,000 SCM x 2.05 = 12,300 kg CO2
• Tools passed: 120,000
• Plant total: 44,250 / 120,000 = 0.369 kg CO2 per piece
• Add steel and plating for the full figure

Inputs are illustrative; use your own bills and production records.

What Senseible does here

Senseible reads the plant's electricity bills (CEA grid factor 0.710 kg CO2 per kWh, CO2 Baseline Database version 21.0) and fuel invoices (IPCC 2006 defaults) into a fingerprinted Scope 1 and 2 record, the plant-level input to a per-unit figure. Bought-in materials go to the supplier evidence trail; product reports are self-declared drafts.

• Product carbon footprint calculator
• Are hand tools covered by CBAM
• Forging footprint
• Electroplating footprint
• Steel industry

Sources: GHG Protocol Product Standard, ISO 14067:2018, Carbon footprint of products (iso.org), IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults), CEA CO2 Baseline Database, version 21.0

Last reviewed 2026-10-20.