Technical Specification for Material Defects to Metal Castings

This Technical Specification describes permissible and non-permissible material defects with regard to iron and steel castings, especially for housings, covers, boxes, brackets, rims and rings etc.

Permissible Defects

1. On surfaces with average roughness Ra ≤ 1.6 are permissible:
a) Maximum 5 cavities (pores, piping, gas pockets, etc.) up to a diameter of max. 0.5 mm and a depth of max 0.5 mm within an area of 5×5 cm.

2. On external profiles (poly-v profiles etc.) are permissible:
a) Maximum 5 cavities (pores, piping, gas pockets, etc.) on the total profile up to a diameter of max. 0.5 mm and a depth of max. 0.5 mm. The distance between the cavities has to be at least 10 mm.

3. On all other surfaces are permissible:
a) Maximum 5 cavities (pores, piping, gas pockets, etc.) up to a diameter of max. 3.0 mm and a depth of max. 0.5 mm within an area of 5×5 cm.
b) Exception: The cavities are smaller than 1.7 mm in diameter. In this case the distance between the cavities has to be at least 3.4 mm.

Not Permissible Defects

a) Cavities at component edges
b) Cavities with edges entailing s risk of particles breaking out
c) Deep cavities (> 0.5 mm)
d) Raw casting spots on machined surfaces (according to the drawing)
e) Defects entailing a risk of loosening due to inhomogeneities in the casting
f) Material defects within contact and sealing surfaces
g) Cracks
h) Impact marks and mechanical defects (scratches, grooves, etc.)

Normative references
DIN EN 1559 part 1-6
DIN EN 1561
DIN EN 1562
DIN EN 1563
DIN EN 1564
DIN EN ISO 945
DIN EN 1706
DIN EN 10293

For more metal casting defects and pictures, please refer to "Metal Casting Defects".

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