Downloaded from https://www.everyspec.com APPENDIX C MIL-STD-31000A Effects of condition on CAD data quality: Non-tangent curves and line segments are not necessarily indicative of poor data quality. In some cases, such as square corners, chamfered, and beveled edges, non-tangent conditions are intended. When curves are intended to be tangent, but aren’t, then G 1 discontinuity is indicative of poor quality. Non-tangent conditions are usually visible to the unaided eye and can be felt by finger tips on physical models. Design or drafting: A quality defect only when tangency is intended. Data exchange: No harmful effects on data exchange. Finite-element analysis:
No harmful effects on mesh generation or model solution. Numerically controlled manufacturing: Sharp edges should generally be avoided in manufacturing (razors and knives are exceptions). However, when making machined parts or parts fabricated from plate stock, removal of sharp edges may be covered by a general note or specification. In such cases, non-tangent curves would not be considered model quality defects. If tangency is intended between curves, non-tangent curves produce noticeable defects in finished products and should be considered model-quality defects. Recommended correction: Adjust one or both entities to make them tangent. 85