SIST EN ISO 15854:2023
(Main)Dentistry - Casting and baseplate waxes (ISO 15854:2023)
Dentistry - Casting and baseplate waxes (ISO 15854:2023)
This document specifies the classification of and requirements for waxes used for dental casting (including products intended for CAD/CAM milling) using the lost-wax technique and dental baseplate preparation together with the test methods to be employed to determine compliance with these requirements.
Solid polymer products (such as acrylics) for CAD/CAM work, and thermoplastic or photo-curing resins used in additive processes, are not covered by this document.
This document does not include specific and quantitative requirements for freedom from biological hazards.
Zahnheilkunde - Guss- und Basisplattenwachse (ISO 15854:2023)
Dieses Dokument legt die Einteilung und die Anforderungen für Wachse fest, die für den dentalen Guss (einschließlich Produkte, die für CAD/CAM-Fräsen bestimmt sind) unter Verwendung des Wachsausschmelzverfahrens und die dentale Basisplattenherstellung verwendet werden, zusammen mit den Prüfverfahren, die angewandt werden, um die Übereinstimmung mit diesen Anforderungen zu bestimmen.
Feste Kunststoffprodukte (wie Acryl) für die CAD/CAM-Arbeit sowie thermoplastische oder lichthärtende Harze, die für additive Verfahren verwendet werden, sind nicht Gegenstand dieses Dokuments.
In diesem Dokument werden keine spezifischen und quantitativen Anforderungen zum Ausschluss biologischer Gefährdungen gestellt.
Médecine bucco-dentaire - Cires pour coulée et pour plaque de base (ISO 15854:2023)
Le présent document spécifie la classification et les exigences relatives aux cires utilisées pour la coulée dentaire (y compris les produits destinés au fraisage CFAO) à l’aide de la technique dite « cire perdue » et la préparation des plaques de base dentaires ainsi que les méthodes d’essai à appliquer pour déterminer la conformité à ces exigences.
Les produits à base de polymères solides (tels que les acryliques) pour les travaux de CFAO, ainsi que les résines thermoplastiques ou photodurcissables utilisées dans les processus additifs, ne sont pas couverts par le présent document.
Le présent document ne spécifie pas les exigences quantitatives spécifiques à l’élimination des risques biologiques.
Zobozdravstvo - Voski za odlitke in podstavke (ISO 15854:2023)
Ta dokument določa razvrstitev in zahteve za voske za zobne odlitke in zobne podstavke skupaj s preskusnimi metodami, ki se uporabljajo za ugotavljanje skladnosti s temi zahtevami.
Ta dokument se ne uporablja za voske, dobavljene za aditivno proizvodnjo ali postopke, ki temeljijo na CAD/CAM.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-september-2023
Nadomešča:
SIST EN ISO 15854:2021
Zobozdravstvo - Voski za odlitke in podstavke (ISO 15854:2023)
Dentistry - Casting and baseplate waxes (ISO 15854:2023)
Zahnheilkunde - Guss- und Basisplattenwachse (ISO 15854:2023)
Médecine bucco-dentaire - Cires pour coulée et pour plaque de base (ISO 15854:2023)
Ta slovenski standard je istoveten z: EN ISO 15854:2023
ICS:
11.060.10 Zobotehnični materiali Dental materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 15854
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2023
EUROPÄISCHE NORM
ICS 11.060.10 Supersedes EN ISO 15854:2021
English Version
Dentistry - Casting and baseplate waxes (ISO 15854:2023)
Médecine bucco-dentaire - Cires pour coulée et pour Zahnheilkunde - Guss- und Basisplattenwachse (ISO
plaque de base (ISO 15854:2023) 15854:2023)
This European Standard was approved by CEN on 23 July 2022.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 15854:2023 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 15854:2023) has been prepared by Technical Committee ISO/TC 106
"Dentistry" in collaboration with Technical Committee CEN/TC 55 “Dentistry” the secretariat of which
is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by December 2023, and conflicting national standards
shall be withdrawn at the latest by December 2023.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 15854:2021.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 15854:2023 has been approved by CEN as EN ISO 15854:2023 without any modification.
INTERNATIONAL ISO
STANDARD 15854
Third edition
2023-01
Dentistry — Casting and baseplate
waxes
Médecine bucco-dentaire — Cires pour coulée et pour plaque de base
Reference number
ISO 15854:2023(E)
ISO 15854:2023(E)
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 15854:2023(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification . 2
5 Requirements . 2
5.1 Appearance . 2
5.2 Flow . 2
5.3 Behaviour on trimming . 3
5.4 Behaviour on softening — Type 1 . 3
5.5 Appearance after flaming . 3
5.6 Behaviour on softening — Type 2 . 3
5.7 Residue on artificial teeth — Type 2 . 3
5.8 Behaviour of colouring material — Type 2 . 3
5.9 Adhesion on storage — Type 2 . 3
5.10 Residue on ignition — Type 1 . 3
5.11 Biocompatibility . 3
6 Sampling . 4
7 Test methods — General . 4
7.1 Ambient temperature . 4
7.2 Apparatus function verification . . 4
8 Test methods — Specific .4
8.1 Visual inspection . 4
8.2 Flow . 4
8.2.1 Principle . 4
8.2.2 Apparatus . 4
8.2.3 Preparation of test pieces . 8
8.2.4 Procedure . 9
8.2.5 Expression of results and evaluation . 10
8.3 Behaviour on trimming test . 11
8.3.1 Principle . 11
8.3.2 Apparatus . 11
8.3.3 Procedure . 11
8.4 Behaviour on softening test — Type 1 . 11
8.4.1 Principle . 11
8.4.2 Apparatus . 11
8.4.3 Procedure . 11
8.5 Appearance after flaming test .12
8.5.1 Principle . 12
8.5.2 Procedure . 12
8.6 Behaviour on softening test — Type 2 .12
8.6.1 Principle . 12
8.6.2 Apparatus . 12
8.6.3 Procedure .12
8.7 Residue on artificial teeth and behaviour of wax colouring material test — Type 2 .12
8.7.1 Principle . 12
8.7.2 Apparatus . 13
8.7.3 Procedure .13
8.8 Adhesion on storage test — Type 2. 14
8.8.1 Principle . 14
iii
ISO 15854:2023(E)
8.8.2 Apparatus . 14
8.8.3 Procedure . 14
8.9 Residue on ignition test— Type 1 . 15
8.9.1 Principle . 15
8.9.2 Apparatus . 15
8.9.3 Procedure . 15
9 Marking and packaging .16
9.1 Marking . 16
9.2 Packaging . 16
10 Test report .16
Annex A (informative) Determination of the melting point of wax .18
Bibliography .20
iv
ISO 15854:2023(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 106, Dentistry, Subcommittee SC 2,
Prosthodontic materials, in collaboration with the European Committee for Standardization (CEN)
Technical Committee CEN/TC 55, Dentistry, in accordance with the Agreement on technical cooperation
between ISO and CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 15854:2021), which has been technically
revised.
The main changes compared with the previous edition are as follows:
— the scope has been clarified;
— waxes supplied for use in CAD/CAM procedures have been included;
— the appearance after flaming has been extended to include casting waxes.
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.
v
ISO 15854:2023(E)
Introduction
For the purposes of this document, the term ‘casting’ includes ‘pressing’, as used for glass ceramics.
It is recommended that, in assessing possible biological or toxicological hazards, reference be made to
ISO 7405 and ISO 10993-1.
vi
INTERNATIONAL STANDARD ISO 15854:2023(E)
Dentistry — Casting and baseplate waxes
1 Scope
This document specifies the classification of and requirements for waxes used for dental casting
(including products intended for CAD/CAM milling) using the lost-wax technique and dental baseplate
preparation together with the test methods to be employed to determine compliance with these
requirements.
Solid polymer products (such as acrylics) for CAD/CAM work, and thermoplastic or photo-curing resins
used in additive processes, are not covered by this document.
This document does not include specific and quantitative requirements for freedom from biological
hazards.
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 1942, Dentistry — Vocabulary
ISO 21920-2, Geometrical product specifications (GPS) — Surface texture: Profile — Part 2: Terms,
definitions and surface texture parameters
ISO 6873, Dentistry — Gypsum products
ISO 8601-1, Date and time — Representations for information interchange — Part 1: Basic rules
ISO 22112, Dentistry — Artificial teeth for dental prostheses
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1942 and the following 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/
3.1
casting wax
mouldable material with minimal residue on ignition suitable primarily for shaping patterns in the
production of cast restorations using the lost-wax technique (3.5)
3.2
baseplate wax
mouldable material primarily for forming occlusion rims, positioning and retaining artificial teeth
therein, and shaping patterns that are duplicated in the denture base polymer
3.3
milling wax
casting wax (3.1) where patterns are formed by milling using CAD/CAM systems
ISO 15854:2023(E)
3.4
melting point
temperature above which no solid material exists at equilibrium
Note 1 to entry: For the practical purposes of this document, the melting point and the freezing point shall be
considered as being the same.
3.5
lost-wax technique
method of casting using a wax pattern that is removed from the intact investment mould by melting or
burning
4 Classification
Dental waxes covered by this document are classified according to the flow characteristics that
represent their hardness, as follows:
a) Type 1 (casting wax, for lost-wax technique):
1) Class 1: Soft;
2) Class 2: Hard;
3) Class 3: Milling.
b) Type 2 (baseplate wax):
1) Class 1: Soft;
2) Class 2: Hard;
3) Class 3: Extra hard.
5 Requirements
5.1 Appearance
The wax shall be uniform in colour, supplied in pieces of uniform size, of smooth texture and free of
foreign materials. Test in accordance with 8.1.
5.2 Flow
The wax when tested in accordance with 8.2 shall have flow values conforming with the appropriate
requirements in Table 1.
Table 1 — Flow requirements percentages
Type 1 Type 2
Temperature
Class 1 Class 2 Class 3 Class 1 Class 2 Class 3
°C
min. max. min. max. max. min. max. min. max. min. max.
23,0 ± 0,2 — — — — — — 1,0 — 0,6 — 0,2
30,0 ± 0,2 — 1,0 — — — — — — — — —
37,0 ± 0,1 — — — 1,0 1,0 5,0 90,0 — 10,0 — 1,2
40,0 ± 0,1 50,0 — — 20,0 20,0 — — — — — —
45,0 ± 0,1 70,0 90,0 70,0 90,0 — — — 50,0 90,0 5,0 50,0
— not required
ISO 15854:2023(E)
5.3 Behaviour on trimming
The wax shall be capable of being trimmed without chipping, flaking or other undesirable behaviour
when tested in accordance with 8.3.
5.4 Behaviour on softening — Type 1
The wax shall soften without flaking or crumbling and shall cohere readily when tested in accordance
with 8.4.
5.5 Appearance after flaming
The wax shall present a smooth glossy surface when tested in accordance with 8.5.
5.6 Behaviour on softening — Type 2
The wax shall soften without becoming sticky or crumbly and shall be mouldable without breaking or
delaminating when tested in accordance with 8.6.
This requirement shall not apply to baseplate preforms where a suitable square test piece cannot be
cut.
5.7 Residue on artificial teeth — Type 2
The wax shall not leave a visible residue on either ceramic or synthetic polymer teeth when tested in
accordance with 8.7.
5.8 Behaviour of colouring material — Type 2
The colouring material shall neither separate from the wax nor impregnate the gypsum mould when
tested in accordance with 8.7.
5.9 Adhesion on storage — Type 2
Adhesion due to storage of the wax shall be such that, when tested in accordance with 8.8, there shall
be no evidence of damage to wax surfaces. Wax and separating paper surfaces shall separate cleanly
and readily.
NOTE The separating paper can possibly not cover the whole area of the wax sheet.
5.10 Residue on ignition — Type 1
If the manufacturer does not state a value for the residue on ignition, the value as determined in
accordance with 8.9 shall be no greater than 0,10 % by mass.
If the residue on ignition is greater than 0,10 % by mass, this value shall be stated by the manufacturer
and the value as determined in accordance with 8.9 shall be not more than 20 % greater than that
stated value.
5.11 Biocompatibility
See ISO 7405 and ISO 10993-1 for guidance on compatibility in respect of waxes that are offered for use
in the mouth or that are not specifically excluded from that application.
ISO 15854:2023(E)
6 Sampling
The amount of material procured for testing shall be at least 250 g for Type 1 or 500 g for Type 2
from one batch and one packet where possible. This material shall be obtained on the open market
unannounced and thus taken randomly from stock.
7 Test methods — General
7.1 Ambient temperature
Unless otherwise specified in this document, all test piece preparation and testing shall be conducted at
an ambient temperature of (23 ± 2) °C. Where necessary and appropriate, all material shall be allowed
to equilibrate at this ambient temperature before testing for at least 24 h.
7.2 Apparatus function verification
All accessories, instruments and equipment shall be examined before use to ensure that they are in
acceptable working order, appropriately calibrated, and complying with specifications stated for them
in this document, as appropriate.
8 Test methods — Specific
8.1 Visual inspection
Carry out the inspection at an illuminance of at least 1 000 lux and at a distance not exceeding 250 mm.
A person making the inspection shall have nominally normal visual acuity. Corrective (non-magnifying)
untinted lenses may be worn.
8.2 Flow
8.2.1 Principle
The relative change in length of the test piece under a given load in a specified time is taken as a proxy
for the inverse of viscosity.
8.2.2 Apparatus
8.2.2.1 Micrometer screw gauge
Micrometer screw gauge with a range of at least 10 mm, being readable and accurate to 0,005 mm or
better, equipped with flat, parallel anvils at least 6,5 mm in diameter and a non-rotating spindle.
Avoidance of indentation of the wax test piece is essential.
8.2.2.2 Flow-testing instrument
Flow-testing instrument, such as shown in Figure 1, consisting of the following components:
— weight (see Figure 1, Key 1);
— shaft, which can move freely in its supports, lubricated as necessary (see Figure 1, Key 2);
— upper platen, metallic, minimum diameter 50 mm, lower surface flat and smooth, rigidly attached
and normal to the axis of the shaft (see Figure 1, Key 3);
ISO 15854:2023(E)
— base plate, metallic, flat smooth and parallel to the lower surface of the upper platen (see Figure 1,
Key 4);
— measuring dial gauge or similarly functional instrument, with a range of at least 10 mm, readable
and accurate to 0,005 mm or better, and rigidly supported (optional) (see Figure 1, Key 5);
— locking screw or equivalent device (required if the dial gauge is used) (see Figure 1, Key 6).
Key
1 weight
2 shaft
3 upper platen
4 base plate
5 dial gauge (optional)
6 locking screw
NOTE This figure is not to scale.
Figure 1 — Conceptual diagram of a suitable flow-testing instrument
The total mass of the components of items 1, 2 and 3 shall be such as to provide an axial compressive
force of (19,6 ± 0,1) N. The weight (Figure 1, Key 1) shall be separated from the surface of the water in
the bath by at least 20 mm. The upper platen (Figure 1, Key 3) shall be at least 5 mm thick for rigidity.
The optional dial gauge (Figure 1, Key 5) and locking screw (Figure 1, Key 6) can replace the micrometer
screw gauge for direct measurement of displacement (see 8.2.3).
The axial force calculation shall take into account the buoyancy of the immersed parts of the shaft and
upper platen (using the value of 0,01 N/ml) and the force exerted by the dial gauge or other measuring
device (Figure 1, Key 5), which force may be about 1 N and vary with its displacement if (as is usual) a
spring is present. Appropriate control of the water level in the water bath (8.2.2.9) is required.
The locking screw or equivalent device shall not cause damage to the shaft (Figure 1, Key 2) and thereby
impede its free movement.
ISO 15854:2023(E)
The base plate (Figure 1, Key 4) can conveniently be marked with a crosshair target, , avoiding
affecting the surface of the central region, to enable the correct location of the test piece.
8.2.2.3 Pouring pan
For melting the wax, use a metal, glass or ceramic vessel, which may have a handle for convenience,
similar in functionality to the example shown in Figure 2.
NOTE A volume of 10 ml to 20 ml can be adequate.
Figure 2 — Example of a suitable pouring pan
8.2.2.4 Heat source
For melting the wax, any convenient low-power or low-temperature system can be used. For example,
— an infrared lamp with nominal power of (250 ± 50) W using a bulb of type R40 or similar;
— a hotplate giving good thermal contact with the base of the pouring pan (8.2.2.3);
— a hot-air oven allowing the wax to be observed.
For preheating the mould (8.2.2.6), slab (8.2.2.7) and glass plate (8.2.2.8), an oven shall be used.
8.2.2.5 Thermometer
To measure the temperature of the molten wax, use an electronic thermometer with an accuracy
of ±0,2 °C and a reading resolution of ±0,1 K or better over the temperature range 20 °C to 100 °C, and
having a 95 % 10 K step change response time of less than 1 min.
8.2.2.6 Mould
For forming the flow test pieces, a metallic mould shall be used, for example made from stainless
steel or brass. This shall consist of a flat plate, (6,00 ± 0,01) mm thick, with parallel top and bottom
surfaces. The plate shall have one or more holes (10,00 ± 0,01) mm in diameter, with the axis of each
hole perpendicular to the surface of the plate. The upper and lower faces of the plate shall be finished
to roughness R ≤ 6,3 µm, and the hole wall shall be finished to roughness R ≤ 0,3 µm, according to
a a
ISO 21920-2.
NOTE It can be convenient to use a multiple mould such that several test pieces can be prepared at a time, for
example as shown in Figure 3.
ISO 15854:2023(E)
Dimensions in millimetres
Figure 3 — Example of a suitable mould for preparing flow test pieces
8.2.2.7 Glass slab
As a base for the mould, use a flat, polished glass slab, large enough for the purpose (i.e. larger than the
extent of the mould plate).
NOTE A dental mixing slab, approximately 150 mm long, 75 mm wide and 19 mm thick, is convenient.
8.2.2.8 Glass plate
For covering the mould (8.2.2.6), use a flat, polished glass plate, large enough for the purpose and
covered with thin, flat aluminium foil. The assembly shall be weighed.
8.2.2.9 Water bath
Use a rigid, stable water bath of sufficiently large volume, equipped with a temperature control device
and a stirring device that together ensure sufficient accuracy, stability and homogeneity of temperature,
according to the tolerances shown in Table 1, over the test volume.
8.2.2.10 Anti-vibration table
If vibration is discernible, or there is an appreciable risk of flow results being affected by vibration, then
an anti-vibration table, for example of the kind used to carry and isolate analytical balances, shall be
used to carry the water bath (8.2.2.9).
NOTE Vibration, such as from traffic and footfall, and in particular the vertical component thereof
(‘hammering’), can cause flow values to be significantly increased, whether or not ordinarily apparent.
The water bath stirring device can, if attached to the water bath itself, be a source of significant
vibration; it is preferable to suspend this component separately to avoid that vibration.
8.2.2.11 Silicone grease
Food-grade poly(dimethylsiloxane)-based, petroleum product-free grease of service temperature range
at least −50 °C to 150 °C, of low to medium viscosity.
ISO 15854:2023(E)
8.2.2.12 Polyethylene film
Flat, smooth, crease and wrinkle-free, in approximately square sheets no less than 50 mm on a side.
8.2.2.13 Timing devices
Clocks or timers to permit intervals from 60 s to 25 h to be noted, accurate and reading to 1 s.
8.2.2.14 Deadweight
For loading the glass plate (8.2.2.8), according to the number of test pieces involved, such that the total
load per test piece is (23 ± 1) N.
8.2.2.15 CAD/CAM machine
For Type 1 Class 3, any milling machine capable of producing the test pieces can be used. The machine
setup, production and post-processing steps and conditions shall follow the requirements of the
‘Instructions for Use’ documentation of both the machine and the material manufacturers.
8.2.3 Preparation of test pieces
8.2.3.1 Type 1 Classes 1 and 2, Type 2
Lubricate the mould (8.2.2.6) internally with a very thin film of silicone grease as release agent and
place it on a smooth glass slab (8.2.2.7). Preheat both to a temperature (10 ± 5) K above the melting
point of the wax, which temperature shall be maintained until the liquid wax is ready to be poured.
NOTE 1 The melting point of the wax, if not known from the manufacturer’s or supplier’s information, can be
determined by a procedure such as that indicated in Annex A.
Place a sufficient quantity of wax, breaking into pieces as necessary, in the pan.
NOTE 2 For guidance, the mould volume is about 0,5 ml per test piece.
If an infrared lamp is used for heating, place the pan on a thermally-insulating surface which is
approximately 130 mm below the infrared lamp (i.e. such that the wax is irradiated from above),
thereby heating the wax. Stir the wax constantly until it is completely melted and its temperature
reaches (10 ± 5) K above the melting point of the wax.
If a hotplate is used for heating, place the pan on the hotplate, thereby heating the pan and thus the
wax. Stir the wax constantly until it is completely melted and its temperature reaches (10 ± 5) K above
the melting point of the wax.
If an oven is used for heating, place the pan in the oven, thereby heating the pan and the wax. Stir the
wax from time to time until it is completely melted and its temperature reaches (10 ± 5) K above the
melting point of the wax.
Once the wax has reached the required temperature, remove the mould (8.2.2.6) and glass slab (8.2.2.7)
from the oven and pour the liquid, without splashing, into the mould. As the wax solidifies and shrinkage
occurs, add more liquid wax, avoiding the trapping of any bubble of air in any ‘pipe’ that is forming. The
mould shall be slightly overfilled to allow for cooling shrinkage and subsequent compression.
The loss of volatile components when the wax is molten can lead to changes in properties. It is
recommended to minimize the time when molten, and preferably to less than 5 min.
When the wax has lost its surface gloss, place a smooth, flat aluminium foil-covered glass plate (8.2.2.8),
preheated to (10 ± 5) K above the melting point of the wax and lubricated as above, on top of the mould
(foil side in contact with the wax). Add the deadweight (8.2.2.14) to the top of the foil-covered glass
plate such as to apply a force of (23 ± 1) N per test piece, and such as to load the test pieces uniformly,
for (30 ± 1) min. Remove the deadweight and the glass plate, carefully peel off the aluminium foil, and
ISO 15854:2023(E)
remove excess wax progressively by drawing a straight-edged non-damaging (e.g. plastic) scraper,
using a negative rake angle, across the mould, repeating as necessary to ensure that each test piece’s
top face is smooth, parallel and flush with the mould's top face.
Cool the mould containing the test piece(s), still resting on the glass slab (8.2.2.7), in water at (23 ± 2) °C
(see 7.1) and then remove the mould from the glass slab. Check that the lower surface of each test piece
is flat, smooth and flush with the mould’s lower surface. Carefully remove each test piece from the
mould. Check that the cylindrical surface is uniformly smooth and flaw-free. If either check shows any
unsatisfactory test piece, replace such test pieces using fresh wax. If the checks are passed, store the
test piece(s) at ambient temperature (see 7.1) for (24 ± 1) h before testing.
Test pieces that fail the check or that exceed 25 h after preparation shall be discarded; the wax shall not
be re-used. Any excess wax from test piece preparation shall not be re-used.
NOTE 3 While the above preparation method is generally satisfactory, in the event that the liquid wax does
not wet the wall of the mould, raising by a few degrees the melt temperature, or the mould preheat temperature,
or both, within the stated tolerance of (10 ± 5) K above the melting point of the wax, can be beneficial in the case
of some products.
8.2.3.2 Type 1 Class 3
Using any recommended or equivalent milling machine (8.2.2.15), prepare flow test pieces
(6,00 ± 0,02) mm high, (10,00 ± 0,02) mm in diameter, with parallel top and bottom surfaces normal
to the cylinder axis. The end faces and the cylinder wall shall be finished to roughness R ≤ 6,3 µm,
a
according to ISO 21920-2. The roughness can be determined by any suitable non-contact method, to
avoid damage to the surface.
Milling wax not intended to be melted may show thermal history effects that compromise flow values.
Where the wax is explicitly available for use by melting, for the purposes of this subclause, it shall be
treated as Type 1 Class 2 and the flow test pieces shall be prepared as in 8.2.3.1.
NOTE The final attachment of a milled test piece to the source block can be dealt with in any appropriate
and usual fashion but such that the design dimensions and surface quality are attained where that attachment is
severed.
Check the dimensions of the test piece using the micrometer screw gauge (8.2.2.1), taking especial care
in measuring the diameter that no damage is done. Check that the upper and lower surfaces of each
test piece are flat, smooth and flaw-free, and that the cylindrical surface is uniformly smooth and flaw-
free. If either check shows any unsatisfactory test piece, replace such test pieces using fresh wax. If the
checks are passed, store the test piece(s) at ambient temperature (see 7.1) for (24 ± 1) h before testing.
Test pieces that fail the checks or that exceed 25 h after preparation shall be discarded.
Excess material or rejected test pieces for Type 1 Class 3, milling wax products that are not explicitly
stated as capable of reuse by recasting shall be discarded and not reused. Milling waste shall not be
reused.
8.2.4 Procedure
Place one test piece, cylinder axis vertical, between two sheets of polyethylene film (8.2.2.12), on the
base plate under the upper platen of the flow-testing instrument, in air, at ambient temperature (7.1),
ensuring that the test-piece axis is closely aligned with that of the shaft (by reference to the crosshair
mark, if present; see 8.2.2.2). Carefully apply an axial compressive force of (19,6 ± 0,1) N to the test
piece at ambient temperature for (60 ± 2) s, and then remove the test piece for measurement. Using the
micrometer screw gauge, determine the length of the test piece (i.e. without the polyethylene films).
Record this as the initial length (L ), to the nearest 0,005 mm. Care shall be taken to avoid marking the
end surfaces of the test piece or warming the test piece in the hands.
Stand the flow-testing instrument in the water bath such that the base plate upper surface is at least
70 mm below the water surface and allow it to equilibrate at the test temperature.
ISO 15854:2023(E)
Immerse the test piece in the water bath by using any suitable means to keep it immersed, in free-
flowing water, and undamaged (e.g. inverted wire mesh basket) and allow it to equilibrate at the test
temperature for (20 ± 1) min.
Keeping it immersed, replace the test piece, cylinder axis vertical, between two sheets of polyethylene
film (8.2.2.12), centred under the upper platen of the flow-testing instrument (by reference to the
crosshair mark, if present; see 8.2.2.2). Gently apply the axial force of (19,6 ± 0,1) N to the test piece for
(10,0 ± 0,1) min. Then, raise the load and remove the test piece from the water bath and cool it in water
at ambient temperature (see 7.1) for (30 ± 1) min. Carefully strip off the polyethylene films and note
whether the end surface(s) are damaged. Using the micrometer screw gauge, determine the final length
(L ).
NOTE Given the caveat in 8.2.2.1 regarding buoyancy, a supplementary weight can be required to be added
for the force specified to be obtained on immersion of the test equipment. This also applies to the alternative
method, given below.
Alternatively, if the flow-testing instrument is equipped with a dial gauge and locking device, at ambient
temperature in air record a fiducial reading on the dial gauge for just two sheets of polyethylene film in
place (i.e. in air). Raise and lock the load system. Place the test piece on the base plate under the platen
between the polyethylene films. Carefully release the locking device and gently apply the axial force to
the test piece at ambient temperature for (60 ± 2) s. Apply the lock and record t
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