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Porosity standards

Engineering Diecasting Specifications

These are acceptable porosity standards for machined surfaces. Acceptance to these standards is on a visual judgement basis without magnification.

Porosity Level 1.

Pin Point Porosity, not larger than 0.25mm ( 0.01") in any direction is acceptable providing it is widely distributed. (Not grouped or connected.)

Random pits, not larger than 0.375mm ( 0.15") in any direction are allowable providing they are widely distributed. (Not grouped or connected.) They must be completely surrounded by dense parent metal and be a minimum of 6mm (0.25") apart.

Frequency of pits must be minimal.

Porosity Level 2.

Pin Point Porosity, not larger than 0.375mm ( 0.015") in any direction is acceptable providing it is widely distributed. (Not grouped or connected.)

Random pits, not larger than 0.75mm ( 0.30") in any direction are allowable providing they are not grouped or connected.

Frequency of pits must not be excessive.

Porosity Level 3.

Pits not larger than 1.25mm ( 0.05") in any direction are acceptable.

Exposed chain porosity must not exceed 3mm (1/8 ") in length.

Unless otherwise specified, exposed porosity on machined diecast parts will conform to this level.