ISO 4095:1998

Aerospace - Bihexagonal drives - Wrenching configuration - Metric series

Aéronautique et espace — Entraînements bihexagonaux — Série métrique

General Information

• Status: Published
• Publication Date: 04-Mar-1998
• ICS: 49.030.20 - Bolts, screws, studs
• Technical Committee: ISO/TC 20/SC 4 - Aerospace fastener systems
• Drafting Committee: ISO/TC 20/SC 4 - Aerospace fastener systems
• Current Stage: 9060 - Close of review
• Completion Date: 04-Mar-2030

Relations

• Revises: ISO 4095:1978 - Fasteners for aerospace construction - Bi-hexagonal wrenching configuration
• Effective Date: 15-Apr-2008

Overview

ISO 4095:1998 is an international design standard that prescribes the metric dimensions and wrenching configuration for aerospace bihexagonal drives. Developed by ISO/TC 20/SC 4, this second edition replaces the original 1978 version and focuses on form, fit and functional geometry to support consistent design and manufacture in the aerospace sector. Dimensions and tolerances are expressed in millimetres and the standard is intended for use prior to any deformation of internal locking elements.

Key Topics

• Metric dimensions and profiles: The standard defines the shape and sizing of bihexagonal drives used in aerospace applications, with dimensions shown in accompanying figure and table references.
• Wrenching configuration: Specifies the wrenching interface geometry to ensure proper engagement and torque transfer for fasteners and drive tools.
• Tolerance system: References ISO 286-2 for standardized tolerance tables and limit deviations, guiding acceptable dimensional variation and fit classes.
• Allowable variation: Permits controlled variations in dimension, form and position over the wrenching height provided the actual profile remains within maximum and minimum material conditions.
• Designation and identification: Describes how to designate the drive geometries for procurement, drawing notes and parts lists.

Applications

ISO 4095:1998 delivers practical value across aerospace engineering, manufacturing and maintenance by enabling:

• Interchangeability: Standardized wrenching geometry allows replacement parts and tools from different suppliers to be used reliably in aircraft assemblies.
• Consistent design: Engineers can specify bihexagonal drives with confidence in fit and function, reducing rework and design ambiguity.
• Quality control and inspection: Dimension and tolerance references support production inspection, acceptance criteria and supplier audits.
• Tooling and maintenance: Provides guidance for tool manufacturers and maintenance teams on compatible wrench profiles and allowable wear limits.
• Documentation and procurement: Clear designation rules simplify ordering, inventory and configuration management for aerospace fasteners.

Related Standards

• ISO 286-2:1988 - referenced for the system of tolerances and standardized limit deviations applicable to dimensions in ISO 4095:1998.
• ISO/TC 20, SC 4 - the technical committee and subcommittee responsible for development of aerospace fastener and fixation element standards.

By applying ISO 4095:1998, designers and manufacturers of aerospace fastening systems ensure reliable engagement, controlled tolerances and improved interchangeability for bihexagonal drive interfaces.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 4095
Second edition
1998-03-15
Aerospace — Bihexagonal drives —
Wrenching configuration — Metric series
Aéronautique et espace — Entraînements bihexagonaux — Série métrique
A
Reference number
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.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard ISO 4095 was prepared by Technical Committee
ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 4, Aerospace
fastener systems.
This second edition cancels and replaces the first edition (ISO 4095:1978),
of which it constitutes a technical revision.
©  ISO 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet [e-mail]
X.400 c=ch; a=400net; p=iso; o=isocs; s=central
Printed in Switzerland
ii
©
INTERNATIONAL STANDARD  ISO ISO 4095:1998(E)
Aerospace — Bihexagonal drives — Wrenching
configuration — Metric series
1  Scope
This International Standard specifies the metric wrenching configuration dimensions of bihexagonal drives.
This is a design standard.
2  Normative reference
The following standard contains provisions which, through reference in this text, constitute provisions of this
Intern
...

NORME ISO
INTERNATIONALE 4095
Deuxième édition
1998-03-15
Aéronautique et espace — Entraînements
bihexagonaux — Série métrique
Aerospace — Bihexagonal drives — Wrenching configuration — Metric
series
A
Numéro de référence
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération
mondiale d'organismes nationaux de normalisation (comités membres de
l'ISO). L'élaboration des Normes internationales est en général confiée aux
comités techniques de l'ISO. Chaque comité membre intéressé par une
étude a le droit de faire partie du comité technique créé à cet effet. Les
organisations internationales, gouvernementales et non gouvernementales,
en liaison avec l'ISO participent également aux travaux. L'ISO collabore
étroitement avec la Commission électrotechnique internationale (CEI) en
ce qui concerne la normalisation électrotechnique.
Les projets de Normes internationales adoptés par les comités techniques
sont soumis aux comités membres pour vote. Leur publication comme
Normes internationales requiert l'approbation de 75 % au moins des
comités membres votants.
La Norme internationale ISO 4095 a été élaborée par le comité technique
ISO/TC 20, Aéronautique et espace, sous-comité SC 4, Éléments de
fixation pour constructions aérospatiales.
Cette deuxième édition annule et remplace la première édition
(ISO 4095:1978), dont elle constitue une révision technique.
©  ISO 1998
Droits de reproduction réservés. Sauf prescription différente, aucune partie de cette publi-
cation ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun pro-
cédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l'accord
écrit de l'éditeur.
Organisation internationale de normalisation
Case postale 56 • CH-1211 Genève 20 • Suisse
Internet [e-mail]
X.400 c=ch; a=400net; p=iso; o=isocs; s=central
Imprimé en Suisse
ii
©
NORME INTERNATIONALE  ISO ISO 4095:1998(F)
Aéronautique et espace — Entraînements bihexagonaux —
Série métrique
1 Domaine d'application
La présente Norme internationale prescrit les dimensions métriques de la forme des entraînements bihexagonaux.
C'est une norme de conception.
2 Référence normative
La norme suivante contient des dispositions qui, par suite de la référence qui en est faite, constituent des
dispositions valables pour la présente Norme internationale. Au moment de la publication,
...