DIN 16742 Tolerances

Tooling Allowance

Toolmakers apply specific shrinkage factors directly to cavity dimensions based on polymer crystallinity and filler orientation. DIN 16742 tolerances dictate how much shrinkage variation is permissible across a given wall thickness or span. Regrind percentages shift melt viscosity and alter volumetric shrinkage rates, which pushes moulded dimensions outside the allowed tolerance band unless the tool geometry compensates for the new material state.

Process Drift

Injection speed, melt temperature, and holding pressure exert immediate control over the final geometry of produced components. DIN 16742 tolerances define the boundary between acceptable dimensional drift and outright part rejection during serial production runs. When barrel temperatures fluctuate beyond permitted limits, local polymer density changes, and the resulting part dimensions violate the specified tolerance class.

Cost Impact

Scrap rates increase sharply when component dimensions slip outside the boundaries established by DIN 16742 tolerances during automated assembly operations. Moulders face higher unit costs because maintaining tight dimensional repeatability requires expensive cavity machining and slower cycle times. Part rejections resulting from thermal expansion differences between virgin feedstock and recycled polymer batches drive up production expenses for the entire manufacturing run.