Aluminum Extrusion & Profile Manufacturing calculator
Aluminum Extrusion Stretch Allowance Calculator Calculator
Stretch allowance protects finished length, straightness, and cut-to-length yield after the profile is pulled, cooled, stretched, and trimmed. This calculator compares available length with required length to show whether enough allowance exists for stretching and end trim.
What this calculator does
- Calculate stretch allowance margin by comparing available runout length, required finished length, and reference length for an aluminum profile.
- a process engineer needs to confirm that runout length supports stretch, trim, and finished cut length requirements
- Returns the length margin available for stretch, end trim, and final cut requirements.
Formula used
- Available stretch and trim length = available as-extruded length - required finished length
- Stretch allowance margin = available stretch and trim length ÷ reference finished length × 100
Inputs explained
- Stretch Allowance available value: undefined
- Stretch Allowance required value: undefined
- Stretch Allowance reference value: undefined
How to use the result
- Use it for long profiles, tight straightness requirements, stretch-straightened sections, and cut-to-length order planning.
- Actual allowance depends on alloy, temper, profile geometry, puller marks, stretch percentage, bow, twist, and customer length tolerance.
Common questions
- What information do I need for stretch allowance? You need available as-extruded length, required finished length, and the reference length used to express the allowance percentage.
- Which length should be the reference? Use the finished length or order length standard used by your plant so allowance percentages compare consistently across profiles.
- What does the stretch allowance margin tell me? It shows how much extra length is available for stretching and trimming before finished length requirements are at risk.
- How can I use this result? Use it to set runout length, reduce short parts, plan end trim, and verify that long profiles can meet customer length tolerance.
Last reviewed 2026-05-12.