English: Residual Stress Can Move the Part After Cutting
Residual stress in CNC milling can cause a precision part to warp after material is removed. This is common in thin plates, frames, aerospace-style components and parts machined from rolled or forged stock. Even when the toolpath is accurate, internal stress release can change flatness, parallelism and final dimensions.
Distortion control starts before finishing. Balanced roughing, flipping strategy, stress-relief planning and uniform finishing allowance can reduce movement. Clamping should support the part without forcing it into a shape that springs back after release.
SEO machining takeaway
When thin parts change shape after unclamping, the problem may not be only tool pressure. Material stress, sequence planning and fixture support should be reviewed together.
中文：CNC 铣削残余应力如何导致零件变形
CNC 铣削中的残余应力会在材料去除后释放，导致精密零件变形。薄板、框架件、航空类结构件以及轧制或锻造毛坯都容易出现这种问题。即使刀路精度很高，内应力释放也可能改变平面度、平行度和最终尺寸。
控制变形应从精加工前开始。对称粗加工、翻面策略、应力释放安排和均匀精加工余量都能减少零件移动。装夹应支撑零件，而不是强行压变形后加工。
Français : Contraintes résiduelles en fraisage CNC
Les contraintes résiduelles peuvent déformer une pièce après enlèvement de matière. Une stratégie d’ébauche équilibrée, une surépaisseur uniforme et un bridage adapté aident à contrôler la stabilité dimensionnelle.
Русский: Остаточные напряжения при CNC-фрезеровании
Остаточные напряжения могут деформировать деталь после снятия материала. Для контроля формы важны симметричная черновая обработка, равномерный припуск и правильное крепление.
FAQ
Why does a part warp after unclamping? Residual stress release, uneven stock removal or forced clamping can cause movement.
How can distortion be reduced? Use balanced roughing, stress relief, uniform finishing stock and stable support.
Related reading: Thin-Wall CNC Milling and CNC Milling Chatter Control.
