Inspection & conditions

Specify plastic dimensions with a conditioning state

A generic polymer name cannot guarantee an achievable machining tolerance. Define the exact material, geometry and inspection conditions with the supplier.

Why a dimension can move after machining

Temperature, moisture, residual stress and workholding can affect final dimensions. Thermal expansion and low stiffness make the measurement and stabilization conditions part of the task.

A practical drawing and supplier brief

Record the full grade/filler, stock form and orientation, feature dimensions, restraint during machining, any agreed stress-relief treatment, stabilization time, temperature/humidity and measurement method. Agree the limits for that state.

Compare like with like

A nylon part measured immediately after machining and one conditioned in service humidity are different dimensional states. Do not use a generic ± table or unrelated ASTM method name as proof that both will meet a limit.

Continue your task

All tolerance and surface references →

Sources and review scope

Reviewed 23 October 2026. Arithmetic examples are labelled separately from source-table facts and standard scope.

Ensinger machining FAQ

Machining, moisture, stress relief and workholding conditions; does not establish universal achievable tolerances by generic polymer name.

Open the original source ↗

Connect tolerances with manufacturability

Review the design-for-manufacturability concept when deciding which dimensions and conditions the drawing must state.