Cutting Optimiser: The Complete Guide to Linear Cutting Optimisation

Every tonne of scrap you generate is material you paid for and cannot sell at full price. Scrap steel goes out at 40p in the pound. That is a 60% loss on every kilogram that lands in the skip instead of in a customer order.

The reason most of that scrap exists is not careless operators. It is a planning problem. The number of ways to cut 50 orders from 200 bars of stock is far beyond what any human can optimise by hand. The best answer requires an algorithm. That is what cutting optimiser software is for.

What Is Linear Cutting Optimisation?

Linear cutting optimisation solves one specific problem: given a set of required cut lengths and a set of available stock lengths, what is the minimum-waste combination of cuts?

The industry calls this the one-dimensional cutting stock problem (1D-CSP) — you are working along a single dimension (the length of a bar, beam, or section). Unlike sheet metal cutting, which involves two dimensions, linear cutting optimisation applies to long products: rebar, structural beams, angle iron, hollow sections, tube, pipe, and bar stock.

The maths behind it is well-established. The problem belongs to a class called NP-hard, meaning the number of possible solutions grows exponentially with the number of orders and bars. A good algorithm explores that search space and finds the near-optimal answer in seconds. A human with a spreadsheet cannot.

How Cutting Optimiser Software Works

Cutting optimiser software takes two inputs: your stock inventory (what bars you have, their actual lengths and grades) and your open orders (what lengths your customers need, in what quantities and grades).

It outputs a cut plan: a structured list of exactly which bars to cut, in what sequence, into what lengths, with the predicted scrap per bar. This cut plan is your production schedule for the saw.

The workflow is straightforward:

1. Upload or sync your inventory and orders
2. The algorithm runs — typically in a few minutes
3. You review the cut plan and override any cuts you want to change (the software recalculates scrap impact immediately)
4. Export to PDF or CSV for the shop floor

What you do not do: sit with a calculator, a yellow legal pad, and a very strong coffee trying to figure out how to squeeze 14 orders from three bundles of 12-metre bar. That morning is over.

The Steel Cutting List Generator

The steel cutting list generator is the output layer of a cutting optimiser. It translates the algorithm’s solution into a format your shop floor can actually use.

A good steel cutting list generator produces:

• Bar-by-bar instructions — exactly which bar from your inventory, exactly what cuts in what order
• Offcut tracking — every remnant above your minimum usable length is flagged for re-stocking rather than binning
• Scrap percentage per bar — so your floor team can see in real time whether the plan is working
• Export formats — PDF for printing and pinning, CSV for feeding into your ERP or CNC machine
• Grade compliance flags — cut instructions that respect grade and certificate requirements per order

GoSmarter’s Cutting Plans includes a steel cutting list generator as standard. Export your cut plan to PDF in one click or to CSV to feed into downstream systems.

Why the format of the steel cutting list matters

A cut plan is only useful if the people doing the cutting can follow it without stopping to ask questions. The best steel cutting list generators present the information bar by bar — one bar, all cuts, the remnant. Simple. The worst ones produce a matrix that requires interpretation. Your saw operator does not have time to interpret.

GoSmarter’s cut list is designed for the saw floor, not the office. Each bar gets its own section. The cuts are listed in sequence. The expected remnant is shown. If the remnant is above the minimum length for tracking, it is flagged as a stock item with a label to print.

Rebar Cutting Optimiser: Why Rebar Is the Hardest Case

Rebar is the most demanding application for a cutting optimiser. Here is why.

Rebar fabricators typically handle hundreds of jobs simultaneously. Each job has multiple bar sizes. Each bar size has many different cut lengths. Every bar must be certified to the correct grade — BS 4449, A500, or Grade 60 depending on the specification. And it all needs to be planned before the saw starts for the day.

Manual planning in this environment consistently produces scrap rates between 5% and 8%. Industry best practice targets 2.5%. The gap between 5% and 2.5% sounds modest. At scale, it is the difference between a profitable operation and one that is quietly haemorrhaging margin on every bundle cut.

A rebar cutting optimiser closes that gap. GoSmarter’s Cutting Plans was built and tested with Midland Steel, a UK rebar and long products manufacturer. In a two-week production trial across 193 jobs and 734 tonnes of steel, the optimiser delivered a scrap rate of below 2.5%.

What makes a rebar cutting optimiser different from generic software

Not all cutting optimiser software is built for the rebar environment. The best cutting optimiser for rebar handles the specific constraints rebar fabrication imposes:

• Multiple bar diameters within the same cut plan
• Grade and certificate compliance per order (no mixing S355 material into an S275 job)
• BS 4449, A500, and Grade 60 specifications
• Manual overrides without breaking the plan integrity
• Offcut tracking back into inventory as usable stock, with heat number and certificate linked
• Works from your live order book, not a batch file
• Exports in formats your shop floor already uses — PDF for the saw operator, CSV for the office

If your rebar operation is currently planning cuts on a spreadsheet or a basic MES, the best way to see the gap is to run the optimiser on a single week of real orders and compare the predicted scrap to what you are currently generating.

Optimise Steel Beam Cutting: The Structural Steel Case

When you need to optimise steel beam cutting, the stakes are higher per cut. Structural members — universal beams (UB), universal columns (UC), parallel flange channels, hollow sections cost significantly more per tonne than rebar. A mis-cut 610×305mm UB goes straight to scrap. You are not bending that back into shape. Getting the plan right first time matters.

The cutting optimiser handles structural sections alongside rebar and other long products. If your business handles a mix of rebar fabrication alongside structural beams you can plan both within the same system.

Where beam cutting efficiency breaks down

Structural beam cutting typically fails at two points:

Under-optimised batch planning. Structural beams are purchased in standard lengths, but project orders require non-standard cuts. Without a cutting optimiser, the default is often to buy new full-length beams when shorter offcuts from previous jobs could cover the requirement. The optimiser checks your offcut inventory first.

Offcut waste. Structural offcuts are valuable because the sections are expensive. A 300mm offcut from a 7m UC might cover a short-span column in a future job. Without systematic offcut tracking, it goes to scrap. GoSmarter tracks every offcut above the minimum usable length automatically, with its certificate and heat number attached.

The difference between 1D optimisation and manual beam planning

Manual beam planning for structural steel often works on a job-by-job basis: allocate stock to this job, deal with offcuts later. A cutting optimiser works across all open jobs simultaneously. It sees that the offcut from Job A can service Job B, and plans accordingly. The result is lower aggregate scrap and lower raw material consumption across the whole production window, not just a single job.

Cutting Plan Efficiency: The Metric That Matters

Cutting plan efficiency is the percentage of material in your cut plan that ends up in a saleable product rather than in the skip.

Formula: (saleable output weight ÷ total material consumed) × 100

A cutting plan efficiency of 97.5% means 2.5% scrap. That is the industry target for rebar and long products. Manual planning often delivers 92–95% efficiency. A well-tuned cutting optimiser consistently delivers 97–98%.

The difference sounds small. It is not.

At 500 tonnes per month of rebar throughput:

• 5% scrap = 25 tonnes of scrap per month
• 2.5% scrap = 12.5 tonnes per month
• At £600/tonne new material vs £220/tonne scrap recovery, the cost gap is £380 for every tonne of excess scrap
• 12.5 extra tonnes per month × £220 = £4,700 per month in avoidable losses
• Over a year: £57,000 in margin you didn’t have to lose

Measuring cutting plan efficiency also tells you when something has gone wrong. A plan that should deliver 97.5% efficiency but is delivering 94% on the floor means either the plan is not being followed, the stock data is wrong, or material has been measured incorrectly. The metric gives you the signal. GoSmarter’s reporting gives you the breakdown by job and by period so you can find the source.

Frequently Asked Questions

Related Resources

• GoSmarter Cutting Plans product page — features, pricing, and free trial
• Scrap, Waste & Yield Optimisation — the complete guide to reducing material waste
• Production Planning Solutions — how the Cutting Optimiser fits into your workflow
• Midland Steel Manufacturing Case Study — 50% scrap reduction in production trials
• AI for Metals Manufacturing — how AI applies across the metals industry
• Smart Cuts, Less Scrap: 1D Cutting Stock Problem — the mathematics behind the optimiser
• What Is Cutting Optimisation? — a plain-English explainer
• Metals Manufacturing Glossary — plain-English definitions for yield rate, off-cuts, and more

GoSmarter is made by Nightingale HQ, a UK-based AI company building practical tools for metals manufacturers since 2018.