KEVOS® MAKEOS · Fabrication
Sheet Nesting Yield Check (Parts per Sheet, Material Utilisation, Sheets and Cost per Part)
How many rectangular blanks of this size can I cut from a standard sheet, what share of the sheet do they use, how many sheets does the order need, and what does the material cost per part?
Rectangular nesting of identical blanks on a sheet for laser, plasma, punch or guillotine cutting: usable sheet after the edge margin, blanks per sheet in a straight grid both ways round and in a two-block layout that fills the leftover strip with blanks turned through 90°, the best layout, material utilisation, sheets needed for the order and material cost per part, against the utilisation you require.
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How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Sheet length | mm | Length of the stock sheet. |
| Sheet width | mm | Width of the stock sheet. |
| Blank length | mm | Length of one rectangular blank (use the bounding rectangle for other shapes). |
| Blank width | mm | Width of one blank. |
| Gap between blanks (kerf and web) | mm | Space between neighbouring blanks: the cutting kerf plus any web the process needs. |
| Edge margin all round | mm | Margin left along every sheet edge (clamping, skeleton or edge quality). |
| Order and cost | ||
| Blanks needed | blanks | Number of blanks the order needs. |
| Price per sheet (ex GST) | AUD | Price of one sheet, ex GST. |
| Lowest utilisation accepted | % | Lowest share of the sheet area the blanks must use for the layout to be acceptable. |
What each input means
Open an input to see what it is, its units, the worked example and the common mistakes, with a small diagram.
What this means: Sheet length
- What it is
- The length of the stock sheet the blanks are cut from.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 100000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 2400 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A longer sheet holds more blanks; utilisation changes in steps as whole rows fit.
- Get it right
- Use the sheet size you can actually buy, such as 2400 × 1200 or 3000 × 1500 mm.
What this means: Sheet width
- What it is
- The width of the stock sheet the blanks are cut from.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 100000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 1200 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A wider sheet holds more rows; utilisation changes in steps.
- Get it right
- Check the width your machine can load; some lasers take only one width.
What this means: Blank length
- What it is
- The length of one rectangular blank, or the bounding rectangle of a shaped part.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 100000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 310 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A small change can add or lose a whole row or column of blanks.
- Get it right
- Use the cut size, not the finished size after bending, and include any trim allowance.
What this means: Blank width
- What it is
- The width of one rectangular blank, or the bounding rectangle of a shaped part.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 100000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 180 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A small change can add or lose a whole row or column of blanks.
- Get it right
- Use the flat blank width before forming.
What this means: Gap between blanks (kerf and web)
- What it is
- The space left between neighbouring blanks: the cutting kerf plus any web the process or part needs.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0 mm to 1000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 5 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A larger gap lowers the blanks per sheet.
- Get it right
- Laser kerf is small, but punching and plasma need wider webs; use your process’s minimum.
What this means: Edge margin all round
- What it is
- The margin left unused along every edge of the sheet for clamping, skeleton strength or poor edge quality.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0 mm to 1000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 10 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A larger margin shrinks the usable sheet and can lose a row of blanks.
- Get it right
- Include the clamp or pallet zone your machine cannot cut.
Order and cost
What this means: Blanks needed
- What it is
- The number of blanks the order needs, used to find the sheets to buy and the material cost per blank.
- Units and format
- Enter a number in blanks: blanks. The form accepts 1 blanks to 100000000 blanks. Use a whole number. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 500 blanks as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Sheets needed rise in steps; the cost per blank changes with the spare blanks on the last sheet.
- Get it right
- Add an allowance for set-up scrap if the first parts are often rejected.
What this means: Price per sheet (ex GST)
- What it is
- The price of one stock sheet, used for the material cost per blank.
- Units and format
- Enter a number in AUD: Australian dollars. The form accepts 0 AUD to 10000000 AUD. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 180 AUD as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The material cost per blank rises in proportion.
- Get it right
- Use the delivered price ex GST for the grade and thickness ordered.
What this means: Lowest utilisation accepted
- What it is
- The lowest share of the sheet area the blanks must cover for the layout to be acceptable.
- Units and format
- Enter a number in %: percent: the number is read as a percentage, so type 8 for 8 %. The form accepts 1% to 100%. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 70% as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Only moves the pass or fail line.
- Get it right
- Set it from your quoting rules; remnants you can reuse may justify a lower figure.
Method and formulas
- Usable area = (L − 2e) × (W − 2e); blanks along a side = ⌊(usable + gap) ÷ (blank + gap)⌋.
- Layouts: straight grid with the blank lengthways, straight grid turned 90°, and two-block layouts that fill whole rows one way and the leftover strip the other way (best taken over every split), in both directions.
- Utilisation = blanks × blank area ÷ sheet area; sheets = ⌈quantity ÷ blanks per sheet⌉; cost per blank = sheets × price ÷ quantity.
- Example: 45 blanks per sheet (87.188 % used); 12 sheets at A$4.32 per blank.
Limitations
- Rectangular blanks; straight grids and two-block layouts are quick rules, and a full guillotine or true-shape nesting search can sometimes fit a few more blanks (one more in the example).
- Ignores grain direction, lead-ins, common-line cutting and remnant reuse, which can change the best layout.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Quote the material for a batch of rectangular blanks
- Choose a sheet size that wastes less
- Check the yield before ordering sheet
Who it is for
- Fabrication estimators
- CNC programmers
- Purchasing staff
What you get
- Blanks per sheet for each layout and the best of them
- Material utilisation
- Sheets needed and leftover blanks
- Material cost per blank
Interpreting the result
- A blank that only just fails to fit one more row or column wastes a whole strip: a small change to the blank or sheet size can raise the yield sharply.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 1338–1339. Topic reference; no source tables or recommended settings are reproduced.
Learn the Concepts Behind This Tool
These KEVOS® Library readings explain the method this tool uses, with worked examples.
Method explained here · KEVOS® original book
Cutting speed, kerf and cost per part
In Laser Processing by the Numbers
What it covers: An energy balance for laser cutting speed, why speeds scale with power and thickness only near a chart value, kerf compensation, piercing and loading time, nesting and cost per part.
Method explained here · KEVOS® original book
Material, blanks and nesting
In Quoting Sheet Metal Work by the Numbers
What it covers: Price material from blanks nested on whole sheets, by sheet price and yield rather than net area, round to sheets per batch, value offcuts, and catch a quote that priced net area and was 26% short.
Method explained here · KEVOS® original book
Nesting the blanks and material yield
In Sheet Metal Production Runs by the Numbers
What it covers: Nest 500 cross-shaped tray blanks: three per 2,400 × 1,200 sheet at 60% yield, why larger sheets do worse, the steel cost with GST, and a nest that ordered 83 sheets too many.
Method explained here · KEVOS® original book
Nesting blanks on sheets
In Shop Floor Optimisation by the Numbers
What it covers: Lay rectangular blanks on stock sheets for least waste: grid and two-block layouts in the KEVOS® sheet nesting tool, the area bound, sheet size choice, mixed nesting and what utilisation hides.
Useful alongside · KEVOS® original book
Strip layout and material yield
In Blanking and Piercing Dies by the Numbers
What it covers: Bridges, edge margins and pitch, MP-40's two possible orientations, 89.8% utilisation, the strip's cost per plate and per year, coil length, and a bridge cut too thin to carry the strip.
Useful alongside · KEVOS® original book
Material, nesting and mass
In Oval Sheet Metal Work by the Numbers
What it covers: Turn the trough's patterns into rectangles on 2,400 × 1,200 mm sheets: two sheets per trough at 54% yield, the finished mass of about 42 kg, the material cost with GST, and sheets ordered by area.
Useful alongside · KEVOS® original book
Checking, nesting and keeping patterns
In Sheet Metal Patterns by the Numbers
What it covers: Check every fitting with independent numbers, compare a CAD unfold, nest the blanks on 2,400 × 1,200 sheets, and keep a pattern register that stops a good pattern being used for the wrong job.
KEVOS® tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.