How do I estimate the carbon footprint of a lathe or CNC machine I export?
Add the castings and steel by mass times their factors, the bought-in motors, drives, controller and other parts from supplier figures or by mass, and your assembly and test energy per machine. For most machine tools the castings and bought-in electronics carry most of the cradle to gate footprint.
Castings and steel
Beds, columns, saddles and tailstocks are usually grey or SG iron castings bought from a foundry. Use the foundry's figure per tonne of good casting if it has one, since a coke-fired cupola and an induction furnace give very different results. Add steel for spindles, guideways, sheet metal guards and fasteners, by mass bought.
Bought-in parts
- Spindle motor, servo motors and drives: supplier product figures if available, otherwise mass by material.
- CNC controller and electronics: ask the supplier. Electronics are heavy in footprint for their weight, so a mass-only estimate tends to understate them; say how you estimated.
- Ball screws, linear guides, bearings, hydraulics, coolant pump: supplier figures or mass by material.
- Wooden crate and packing: by mass, if the buyer asks for packed product.
Assembly, scraping and testing energy
Machine tools are built in small numbers, so do not divide a month's power by machines shipped. Divide by assembly hours instead: each machine's share is its hours over total hours worked that month. Include machining of castings, painting, the test run and any accuracy checks.
Use phase is a separate figure
A machine's electricity over its life usually dwarfs its manufacturing footprint. Buyers may ask how its energy use was evaluated under the ISO 14955 series: Part 1 covers design methodology for energy-efficient machine tools, and Part 2 covers measuring the energy a machine and its components take. Report that alongside the cradle to gate figure, not inside it.
Illustrative example: a 3 tonne CNC lathe
- Castings 2,000 kg x 1.5 = 3,000 kg CO2e
- Steel parts 600 kg x 2.0 = 1,200 kg CO2e
- Motors and drives 120 kg x 5.0 = 600 kg CO2e
- Controller and electronics: supplier figure 400 kg CO2e
- Assembly: 400 of 4,000 shop hours in a 25,000 kWh month = 2,500 kWh, x 0.710 = 1,775 kg CO2
- Total: 3,000 + 1,200 + 600 + 400 + 1,775 = 6,975 kg CO2e, about 7.0 tonnes per machine
Material factors (kg CO2e per kg) and the controller figure are placeholders to show the arithmetic. Use your foundry's, steel mill's and suppliers' own figures.
What Senseible does here
Senseible reads your workshop's electricity and fuel bills into Scope 1 and 2 totals, which you share across machines by assembly hours. Casting and component factors come from your suppliers or published data.
- CNC machined part footprint
- Foundry footprint per tonne of casting
- How to count a new machine in Scope 3
- Product carbon footprint calculator
Sources: ISO 14067:2018, Carbon footprint of products (iso.org), ISO 14955-1, Machine tools: environmental evaluation of machine tools, design methodology for energy-efficient machine tools (iso.org), GHG Protocol Product Life Cycle Accounting and Reporting Standard (2011), ISO 14955-2, Machine tools: environmental evaluation of machine tools, methods for measuring energy supplied to machine tools and machine tool components (iso.org)
Last reviewed 2026-10-18.