ISO 4993:2024

International
Standard
ISO 4993
Fourth edition
Steel and iron castings —
2024-03
Radiographic testing
Pièces moulées en acier ou en fonte — Contrôle radiographique
Reference number
© ISO 2024
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Basis of purchase . 2
5 General . 2
6 Testing parameters . 2
7 Personnel qualifications . . 3
8 Testing arrangements . 3
9 Film position plan . 3
9.1 Film position plan for pilot radiography .3
9.2 Film position plan for production radiography.4
10 Rejection/acceptance criteria . 4
11 Foundry responsibility. 4
Annex A (informative) Testing arrangements . 5
Annex B (informative) Techniques for increasing the covered thickness range .10
Annex C (informative) Choice of radiation source .13

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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This document was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 11, Steel castings.
This fourth edition cancels and replaces the third edition (ISO 4993:2015), which has been technically
revised.
The main changes are as follows:
— Annex A was rewritten to include a table for the various testing arrangements;
— term “examination” being replaced with testing.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
Radiography can be used to detect internal discontinuities in castings. The discontinuities can have higher
or lower densities than the parent metal.

v
International Standard ISO 4993:2024(en)
Steel and iron castings — Radiographic testing
1 Scope
This document specifies the general requirements for the radiography of steel and iron castings by means of
X-rays or gamma-rays.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 5579, Non-destructive testing — Radiographic testing of metallic materials using film and X- or gamma rays
— Basic rules
ISO 9712, Non-destructive testing — Qualification and certification of NDT personnel
ISO 19232-1, Non-destructive testing — Image quality of radiographs — Part 1: Determination of the image
quality value using wire-type image quality indicators
ISO 19232-2, Non-destructive testing — Image quality of radiographs — Part 2: Determination of the image
quality value using step/hole-type image quality indicators
ISO 19232-3, Non-destructive testing — Image quality of radiographs — Part 3: Image quality classes
ISO 19232-4, Non-destructive testing — Image quality of radiographs — Part 4: Experimental evaluation of
image quality values and image quality tables
ISO 19232-5, Non-destructive testing — Image quality of radiographs — Part 5: Determination of the image
unsharpness and basic spatial resolution value using duplex wire-type image quality indicators
ASTM E186, Standard Reference Radiographs for Heavy-Walled (2 to 4 1/2 in. [50,8 to 114 mm]) Steel Castings
ASTM E192, Standard Reference Radiographs for Investment Steel Castings for Aerospace Applications
ASTM E280, Standard Reference Radiographs for Heavy-Walled (4 1/2 to 12 in. [114 to 305 mm]) Steel Castings
ASTM E446, Standard Reference Radiographs for Steel Castings up to 2 in. (50,8 mm) in Thickness
ASTM E689, Standard Reference Radiographs for Ductile Iron Castings
ASTM E802, Standard Reference Radiographs for Gray Iron Castings up to 4 1/2 in. (114 mm) in Thickness
ASTM E2660, Standard Digital Reference Images for Investment Steel Castings for Aerospace Applications
ASTM E8268, Standard Digital Reference Images for Steel Castings up to 2in. (50.8 mm) in Thickness
ASTM E3030, Standard Digital Reference Images for Heavy-Walled (2 to 412 In. (50.8 to 114 mm)) Steel Castings
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5579 apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Basis of purchase
The request for radiographic testing and all requirements, see Clause 6, should be indicated in the enquiry
and order.
Unless otherwise specified in the enquiry and order, the radiographic coverage can be of two types, i.e. pilot
or regular production inspection. For both types, the manufacturing plan shall show the area to be examined
and the frequency of testing. The acceptance criteria, see Clause 10, shall be subject to agreement between
the manufacturer and purchaser.
Castings with a complex geometry can include areas that cannot be radiographically inspected or can only
be partly inspected. Such areas shall be identified before starting the radiographic testing. Areas that cannot
be radiographically inspected shall be noted by all contracting parties and be marked on the film position
plan.
5 General
Relevant safety precautions shall be applied when using ionizing radiation.
WARNING — Exposure of any part of the human body to X-rays or gamma-rays can be highly harmful
to health.
6 Testing parameters
Unless otherwise requested in the enquiry and order, the radiographic testing may be performed at any
point in the manufacturing cycle, before or after the final heat-treatment.
The surface should be conditioned so that surface irregularities cannot mask or be confused with
discontinuities.
Any type of penetrameter or image quality indicator can be used, provided that the sensitivity level indicated
by the purchaser is achieved.
The following items shall be agreed upon between the purchaser and manufacturer:
a) manufacturing stage;
b) extent of testing;
c) testing areas;
d) surface condition;
e) test class in accordance with ISO 5579;
f) information about the film position plan;
g) marking of testing areas on the casting;
h) image quality value, in accordance with ISO 19232 series;
i) traceability of the films or digital images;
j) acceptance criteria.
Any additional items shall be agreed upon between the purchaser and manufacturer.
Radiographs shall be evaluated by comparison to reference radiographs.
7 Personnel qualifications
Operations shall be carried out by qualified personnel according to ISO 9712. The system of qualification
shall be agreed upon between the purchaser and manufacturer.
8 Testing arrangements
Testing arrangements shall be agreed upon between the purchaser and the manufacturer. Some possible
arrangements are in Annex A.
9 Film position plan
9.1 Film position plan for pilot radiography
When requested in the order or enquiry, preliminary shooting sketches shall be prepared by the
manufacturer for submission with the radiographs of the pilot casting for approval by the customer. These
sketches shall show the area of the part to be examined and shall include the following information for each
exposure:
a) name, address of test facility performing the testing;
b) part number and description;
c) instruction identification number, issue No. and date of issue;
d) material including requirements for surface preparation;
e) gamma source or kV used, tube current, exposure time, see Annex C for additional information about
the choice of source used;
f) physical size of the source;
g) location of radiation source in relation to the area covered and the film;
h) angle of beam to film;
i) object-to-film distance;
j) film-to-source distance;
k) section thickness, Annex B lists various techniques to increase the covered thickness range;
l) areas of the item to be examined (support by diagrams when required);
m) placement of the film and location ma
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