Mixed-length bar allocation
Mixed-Length Stock Cut Layout
Plan multiple required lengths from one identical stock specification. The worksheet assigns every requested piece to a numbered bar and reports its remaining length. It does not produce an approved saw program or a minimum possible bar count.
Enter measurements → review geometry or arithmetic → confirm the real application. No order or approval is generated.
Enter your records
Required inputs must be complete. Only fields marked optional may be left blank. Enter 0 only when zero is deliberate; missing values remain unresolved. Use non-confidential references only.
Record fields
- Shared stock material, section, finish and direction
- Original stock length (mm)
- Start trim (mm; 0 if none)
- End trim (mm; 0 if none)
- Kerf between adjacent parts (mm)
- Unique part reference
- Finished part length (mm)
- Required whole-piece quantity
Reviewable result
Enter records to begin.
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Worked example
A buyer plans how many 6000 mm aluminum profile bars a shower enclosure order needs when three different finished lengths are cut from one stock specification.
Example figures are invented for illustration. They are not product data, prices or a quotation.
Whole-worksheet settings
| Shared stock material, section, finish and direction | Aluminum U-channel 20 x 10, matte black, one direction |
|---|---|
| Original stock length (mm) | 6000 |
| Start trim (mm; 0 if none) | 10 |
| End trim (mm; 0 if none) | 10 |
| Kerf between adjacent parts (mm) | 3 |
Example inputs
| Unique part reference | Finished part length (mm) | Required whole-piece quantity |
|---|---|---|
| Part A1 | 2400 | 4 |
| Part A2 | 1500 | 6 |
| Part A3 | 900 | 8 |
Result from the worksheet
Mixed-Length Stock Cut Layout LOCAL WORKSHEET — entered data only Stock identity: Aluminum U-channel 20 x 10, matte black, one direction Original stock length: 6000 mm; start trim: 10 mm; end trim: 10 mm. Heuristic allocation: 5 bars; 18 pieces. Not guaranteed optimal. Usable length per bar: 5980 mm; kerf between adjacent parts: 3 mm. Bar 1: Part A1 (2400 mm) + Part A1 (2400 mm) + Part A3 (900 mm) | part length 5700 mm; internal kerf 6 mm; remainder 274 mm. Bar 2: Part A1 (2400 mm) + Part A1 (2400 mm) + Part A3 (900 mm) | part length 5700 mm; internal kerf 6 mm; remainder 274 mm. Bar 3: Part A2 (1500 mm) + Part A2 (1500 mm) + Part A2 (1500 mm) + Part A3 (900 mm) | part length 5400 mm; internal kerf 9 mm; remainder 571 mm. Bar 4: Part A2 (1500 mm) + Part A2 (1500 mm) + Part A2 (1500 mm) + Part A3 (900 mm) | part length 5400 mm; internal kerf 9 mm; remainder 571 mm. Bar 5: Part A3 (900 mm) + Part A3 (900 mm) + Part A3 (900 mm) + Part A3 (900 mm) | part length 3600 mm; internal kerf 9 mm; remainder 2371 mm. No product, inspection, installation, stock or delivery approval is generated.
How to read it
Usable length is 6000 - 10 - 10 = 5980 mm. Bar 1 holds 2400 + 2400 + 900 = 5700 mm of parts plus 6 mm of kerf (2 x 3), leaving 274 mm. All 18 pieces fit on 5 bars, and bar 5 leaves 2371 mm. This is one feasible layout, not a proven minimum, and the remainder is not usable stock until the fabricator confirms it.
How the pieces are assigned
Usable length is original stock length minus both trims. Pieces are sorted from longest to shortest, with ties kept in input order. Each piece goes into the first previously opened bar that can hold it; otherwise a new bar is opened. An occupied bar needs the piece length plus one additional kerf. This is first-fit decreasing, a deterministic feasible-layout heuristic, not a guarantee of minimum stock consumption.
Review every bar, not only the total
For each bar, the sum of part lengths plus (piece count minus one) × kerf cannot exceed usable length. The result lists the piece references, internal kerf total and remainder. The chart shows the first twenty bars only; the complete text contains every bar. Gray unused length is not automatically reusable stock.
Keep stock identity and cutting allowances explicit
All pieces must be suitable for the same material, cross-section, finish, stock length and direction stated above. Do not combine different profiles or batches merely because their lengths fit. Kerf is included only between adjacent parts in a pre-trimmed usable length; any outer boundary cut allowance must be included in your trim inputs. Angled cuts, defects, clamps, grain matching, end machining and toolpath sequencing are excluded.
Supported input scope
Enter positive stock and finished lengths, nonnegative trims and kerf, and positive whole-piece quantities. Numeric lengths accept at most six decimal places and magnitude 1,000,000 mm. Exact scaled-integer arithmetic is used for fit decisions. There may be up to fifty part records and two thousand expanded pieces. Duplicate part references, oversize pieces and trims that leave no usable stock block the calculation.
A feasible example can still be nonoptimal
With a usable length of 10, zero kerf and pieces 6, 5, 3, 2, 2, 2 in the same unit, this heuristic uses three bars although a two-bar arrangement exists. This arithmetic illustration is not a cutting recommendation. Have the fabricator review the complete layout and production constraints before ordering stock or cutting.
Mixed-length bar allocation questions
Does the reported bar count prove the minimum possible consumption?
No. First-fit decreasing is a feasible heuristic, not an optimizer.
Where is kerf deducted?
Between adjacent pieces on each bar; outer cut allowances belong in the entered trims.
Will an oversize part be silently left out?
No. Any part longer than usable stock blocks the calculation.
Can different stock sections share one calculation?
No. Use a separate calculation for each identical stock specification.
Does the diagram include every bar when the result is large?
It shows the first twenty; the text result lists all bars.
Discuss the reviewed requirement
Use the result to identify questions for WNS Global. Offered products, specifications and commercial conditions still require separate confirmation.