Φ2 (inner diameter 2±0 earlier than shrinkage, wall thickness 0±0; After total shrinkage, the interior diameter ≤0, and the wall thickness is 0±0)
Φ4 (inner diameter 4±0 earlier than shrinkage, wall thickness 0±0; After total shrinkage, the inner diameter ≤1, and the wall thickness is 0±0)
Φ6 (inner diameter 6±0 before shrinkage, wall thickness 0±0; After complete shrinkage, the interior diameter ≤1, and the wall thickness is 0±0)
Φ8 (inner diameter 8±0 before shrinkage, wall thickness 0±0; After complete shrinkage, the internal diameter ≤1, and the wall thickness is 0±0)
Φ9 (inner diameter 9±0 earlier than shrinkage, wall thickness 0±0; After total shrinkage, the inner diameter ≤2, and the wall thickness is 0±0)