Aluminum Casting Standards: ASTM vs ISO 8062 and IATF

Automotive casting RFQs often list ASTM, SAE, ISO and IATF references as though they were interchangeable. They are not. A material specification, tensile test method, reference radiograph, surface-texture vocabulary and quality-management-system requirement answer different questions.

Which ISO standard applies to aluminium castings?

There is no single ISO reference that covers alloy chemistry, every drawing tolerance, inspection and supplier certification together. For general casting dimensions and machining allowances, ISO 8062-3:2023 covers indicated dimensions using plus/minus tolerances and specified general geometrical tolerances. Its scope does not extend to a 3D CAD model supplied without indicated dimensions.

For an A356 permanent-mold part, the material requirements may instead reference ASTM B108/B108M. The dimensional and material documents can appear on the same drawing: one does not replace the other. A customer may mandate a different system, so agree the specification and edition before quoting.

Start with the supplied part and process, then assign one controlling document to each requirement. Use the casting tolerance guide for dimensional planning and Bohua's certification page to distinguish the actual quality-system certificate from product inspection records.

Scope map

Two corrections that matter

First, AMS2175 is not a surface-finish standard. SAE describes it as a casting-classification and inspection specification establishing nondestructive-testing methods, sampling frequency and acceptance criteria.

Second, ISO 4287:1997 is withdrawn. ISO lists ISO 21920-2:2021 as the current published successor for profile surface-texture terms, definitions and parameters. A drawing conversion still needs engineering review because the new ISO 21920 series changed more than the document number.

Radiographic references must match the process

ASTM E505 explicitly covers aluminium- and magnesium-alloy die castings. It should not be presented as the default acceptance table for a gravity permanent-mold casting. For other casting routes, select a reference image standard whose scope, material, thickness, image type and inspection method fit the part, then state the acceptance category and severity in the drawing or inspection plan.

Do not write "meet ASTM E505" without specifying what is being inspected and what acceptance level applies. A reference radiograph helps communicate discontinuity type and severity; it does not by itself create a complete acceptance plan.

For digital-image requirements, the digital radiography checklist separates image reference, technique, zones and acceptance. It is a planning guide, not a test report for your casting.

IATF 16949 does not set A356 strength

IATF 16949 governs the automotive quality-management system and connects to customer-specific requirements, control plans, traceability and production approval. It does not prescribe a universal tensile strength, elongation or porosity level for an A356 casting. Those product requirements belong in the drawing, material specification and customer requirements.

RFQ checklist

For each cited document, record:

• •full designation and edition;
• •whether it is current, withdrawn or customer-mandated;
• •the document's actual scope;
• •the characteristic it controls;
• •inspection method, frequency and acceptance criterion;
• •any customer-specific requirement that overrides the general document;
• •responsibility for buying and interpreting the controlled copy.

Send the standards matrix with the drawing through the automotive casting RFQ form.

*This scope map is procurement guidance. The current controlled standards, drawing and customer-specific requirements govern the project.*