SIST EN 4408-006:2005

• Abstract:

  This standard specifies the rules for the representation of preforms of composite materials as well as the information to be indicated in the technical drawings.; It is applicable to aerospace structures using preforms.; It shall be used together with EN 4408-1.

• Status: Published
• Publication Date: 31-Aug-2005
• ICS: 01.100.99 - Other standards related to technical drawings
• ICS: 49.020 - Aircraft and space vehicles in general
• Technical Committee: SS SPL - Technical Board for the general field
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Sep-2005
• Due Date: 01-Sep-2005
• Completion Date: 01-Sep-2005
• Ref Project: EN 4408-006:2005 - Aerospace series - Technical drawings - Representation of parts made of composite materials - Part 6: Preforms

• Refers: SIST EN 4408-001:2005 - Aerospace series - Technical drawings - Representation of parts made of composite materials - Part 1: General rules
• Effective Date: 28-Jan-2026

SIST EN 4408-006:2005 is the Slovenian version of EN 4408-006:2005, a CEN European Standard for aerospace technical drawings of composite-material preforms. It specifies how preforms are represented on drawings and what information is to be indicated so the designer, manufacturer and checker understand the same preform in the same way. It is used together with EN 4408-001, which provides the general drawing rules.

What does SIST EN 4408-006:2005 specify?

SIST EN 4408-006:2005 defines the drawing rules for preforms used in aerospace structures and the information that has to appear on the technical drawing. The document is focused on representation, not on manufacturing methods for the finished composite part.

The standard is organized into four clauses and one informative annex:

• Clause 1 - Scope
• Clause 2 - Normative references
• Clause 3 - Terms and definitions
• Clause 4 - Representation of preforms on drawings
• Annex A - Informative example of 2,5 D weaving representation

Annex	What it covers
A	Informative example of the representation of 2,5 D weaving

What are the key requirements of SIST EN 4408-006:2005?

SIST EN 4408-006:2005 sets out how to show each preform type on a drawing and which identifying details must accompany it. The practical goal is to make the drawing usable for definition, manufacturing and checking without ambiguity.

General drawing approach

Clause 4 states that preforms can be difficult to describe because of their complexity and the different ways they are made. The drawing therefore has to use the general rules from EN 4408-001 and add the specific features that identify the preform type.

In practice, this means the drawing must not rely on a generic shape alone. It has to show the structural features that affect how the preform will be built and interpreted.

2,5 D multilayers

Clause 4.1 gives the representation approach for 2,5 D multilayers. The drawing needs to identify the number of intertwined layers, the repeated motif, and the quantity of threads in the warp and weft directions.

This matters because 2,5 D structures vary by layer count and thread path. The drawing must therefore carry enough structural detail for the required preform geometry to be reproduced.

Rosettes and nDs

Clause 4.2 says rosettes are represented with the outside diameter, inside diameter, thickness, spiral angle and any extra information needed for understanding. Clause 4.3 says nDs are shown with a conventional image and a perspective view, plus enough cross-sections to make the requirement clear.

In practice, rosettes need geometry and layer data on the drawing, while nDs need views that explain the orientation of the reinforcement. The standard is aimed at avoiding misreading of layered circular forms and multidirectional reinforcements.

Braids

Clause 4.4 requires braid drawings to include the information needed for manufacture and to use the rules for draped items, with additions for the final geometry of the braid. The braiding angle is given in a braiding table, and areas can be marked to show where the braiding direction or angle changes.

This is useful when the braid changes section by section. The drawing has to tell the manufacturer where the angle changes and how the braid follows the part shape.

Woven and cowoven parts

Clause 4.5 applies the draped-items and seam representation rules to woven and cowoven parts, together with the symbols shown in the standard. The drawing uses a grafting table and lay-up diagram to identify the layers, directions and areas involved.

This means the drawing should make the fabric build-up readable at a glance. For these parts, the key task is to show how the woven structure and any shape changes are laid out.

What terms does SIST EN 4408-006:2005 define?

• braided - A tubular or plane shape made by balanced intertwining of continuous threads.
• braided into shape - A braided form made with a mandrel.
• cowoven (hybrid fabric) - A fabric made from different kinds of threads, such as carbon/aramid combinations.
• level - The elementary structure of one layer in the weft or warp direction.
• multilayer (2,5 D) - A fabric where the weft threads cross several warp levels, but not all of them.
• nD - Oriented multidirectional reinforcement, identified in the standard as an industrial copyright term.
• preform - The intermediate stage of the part before the required composite material is obtained.
• rosette - A circular piling of staggered layers in the same direction with overlap.
• woven - A plane surface made from intertwined threads forming a definite framework.
• woven into shape - A woven non-plain shape, with or without a shaping tool.

Who uses SIST EN 4408-006:2005?

SIST EN 4408-006:2005 is used by people who prepare or check technical drawings for aerospace composite structures that use preforms. That includes design engineers, draughtspersons, manufacturing teams and quality personnel who need the drawing to describe the preform clearly enough for production and review.

It is also relevant to suppliers making preforms from braided, woven, rosette or multilayer structures. For them, the drawing is the shared definition of geometry, orientation and layer arrangement.

Which standards are used with SIST EN 4408-006:2005?

• EN 4408-001 - The general rules for aerospace technical drawings of composite parts, and the common terms and definitions used with this part.
• EN 4408-002 - Companion part for laminated parts.
• EN 4408-003 - Companion part for parts including core materials.
• EN 4408-004 - Companion part for items obtained by winding.
• EN 4408-005 - Companion part for seams.

What does the SIST EN 4408-006:2005 document contain?

The document contains a short set of clauses and a focused set of drawing examples for different preform families. Clause 4 includes separate guidance for 2,5 D multilayers, rosettes, nDs, braids, and woven or cowoven parts.

It also contains Figure 1 to Figure 6, plus tables used to show braiding and grafting information on drawings. Annex A gives an informative example of 2,5 D weaving, including the kind of layer and thread views used to explain the structure.

The bibliography points to the other parts of the EN 4408 series for related composite-part drawing topics.

SLOVENSKI STANDARD
01-september-2005
Aeronavtika – Tehniške risbe – Prikaz delov, izdelanih iz kompozitov – 6. del:
Predhodne oblike
Aerospace series - Technical drawings - Representation of parts made of composite
materials - Part 6: Preforms
Luft- und Raumfahrt - Technische Zeichnungen - Darstellung von Teilen aus
Verbundwerkstoffen - Teil 6: Vorformen
Série aérospatiale - Dessins techniques - Représentation des articles en matériaux
composites - Partie 6 : Préformes
Ta slovenski standard je istoveten z: EN 4408-006:2005
ICS:
01.100.99 'UXJLVWDQGDUGLY]YH]LV Other standards related to
WHKQLþQLPULVDQMHP technical drawings
49.020 Letala in vesoljska vozila na Aircraft and space vehicles in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 4408-006
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2005
ICS 01.100.99; 49.020
English version
Aerospace series - Technical drawings - Representation of parts
made of composite materials - Part 6: Preforms
Série aérospatiale - Dessins techniques - Représentation Luft- und Raumfahrt - Technische Zeichnungen -
des articles en matériaux composites - Partie 6 : Préformes Darstellung von Teilen aus Verbundwerkstoffen - Teil 6:
Vorformen
This European Standard was approved by CEN on 15 July 2004.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 4408-006:2005: E
worldwide for CEN national Members.

Contents Page
Foreword .3
1 Scope.4
2 Normative references.4
3 Terms and definitions.4
4 Representation of preforms on drawings .5
4.1 Representation of 2,5 D multilayers .5
4.2 Representation of rosettes.6
4.3 Representation of nDs.7
4.4 Representation of braids.7
4.5 Representation of woven and cowoven parts .9
Annex A (informative) Example of the representation of 2,5 D weaving.10
Bibliography.12

Foreword
This document (EN 4408-006:2005) has been prepared by the European Association of Aerospace
Manufacturers - Standardization (AECMA-STAN).
After enquiries and votes carried out in accordance with the rules of this Association, this Standard has
received the approval of the National Associations and the Official Services of the member countries of
AECMA, prior to its presentation to CEN.
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 November 2005, and conflicting national standards shall be withdrawn
at the latest by November 2005.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland
and the United Kingdom.
1 Scope
This standard specifies the rules for the representation of preforms of composite materials as well as the
information to be indicated in the technical drawings.
It is applicable to aerospace structures using preforms.
It shall be used together with EN 4408-001.
2 Normative references
The following referenced documents are indispensable for the application 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.
EN 4408-001, Aerospace series – Technical drawings – Representation of parts made of composite materials
– Part 1: General rules.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 4408-001 and the following apply.
3.1
braided
tubular or plane shape obtained by a balance intertwining of continuous threads
3.2
braided into shape
braided with a mandrel
3.3
cowoven (hybrid fabric)
fabric made of different types of threads (e.g. carbon/aramid hybrid fabric)
3.4
cowoven into shape
woven into shape and made of different types of threads
3.5
level
elementary structure of one layer in the weft or warp direction
3.6
multilayer (2,5 D)
fabric the weft threads of which cross several levels of warp but not all of them
3.7
nD
oriented multidirectional reinforcement (industrial copyright)
3.8
preform
name given to different stage of all part of the item prior to obtaining the required composite material
SIST EN 4408
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