Fast underground belt — Factorio Production Calculator
Fast underground belt is crafted in the assembling machine in 2 seconds, producing 2 per craft from 40 × Iron gear wheel, 2 × Underground belt. At 60 per minute you need 2 assembling machines, and the chain behind it draws on 1 raw resources: iron ore.
Production chain for 60 Fast underground belt / minute
| Item | Per minute | Machines | Machine |
|---|---|---|---|
| Iron plate | 2,925 | 156 | Furnace |
| Iron gear wheel | 1,275 | 21.25 | Assembling machine |
| Transport belt | 150 | 1.25 | Assembling machine |
| Fast underground belt | 60 | 2 | Assembling machine |
| Underground belt | 60 | 1 | Assembling machine |
Raw materials
| Resource | Per minute |
|---|---|
| Iron ore | 2,925 |
Machine counts are not rounded up. Add a little headroom in game — belt throughput and inserter speed usually mean you want 5-10% more than the exact number.
Fast underground belt recipe
| Machine | Crafting time | Output | Ingredients |
|---|---|---|---|
| Assembling machine | 2 s | 2 | Iron gear wheel × 40, Underground belt × 2 |
What the whole chain needs
60 fast underground belts per minute pulls in 4 intermediate products, and the whole tree comes to 182 machines across 2 machine types, fed by 1 raw resource. The table above already sums demand across every branch — if copper cable is used by two recipes, you see the total, not one of them.
Belt check: the busiest input here moves 2,925 per minute, which is 3.25 of a yellow belt's 900 per minute. Above 1.0 and you need a second belt (or a faster tier) before the machines themselves become the limit.
What uses fast underground belt
1 base-game recipe consumes fast underground belt, sorted by how much each one takes:
- Express underground belt — 2 per craft
What fast underground belt is made from
- Iron gear wheel — 40 per craft
- Underground belt — 2 per craft
FAQ
How many assembling machines do I need for 60 fast underground belts per minute?
2 assembling machines. One at standard speed produces 30 per minute, so 60 ÷ that number is the count. The calculator above rounds nothing — add 5-10% headroom for belt and inserter losses in a real factory.
How much raw ore does fast underground belt take?
At 60/min the chain consumes 2,925 iron ore per minute. Those numbers are the theoretical minimum — mining productivity research and productivity modules both reduce them.
Is fast underground belt needed for science packs?
Not directly. It feeds Express underground belt, and those in turn feed the science packs. Open the science pack page to see the demand that lands on this recipe.
Machine counts assume bare machines at standard speed. Recipe data comes from the game's own prototypes (PlayerCalc, Factorio 2.0 base game). Not affiliated with Wube Software.