ISO 4254-13:2012

INTERNATIONAL ISO
STANDARD 4254-13
First edition
2012-08-01
Corrected version
2014-12-15
Agricultural machinery — Safety —
Part 13:
Large rotary mowers
Matériel agricole — Sécurité —
Partie 13: Grandes faucheuses rotatives
Reference number
ISO 4254-13:2012(E)
©
ISO 2012

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ISO 4254-13:2012(E)

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© ISO 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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Published in Switzerland
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ISO 4254-13:2012(E)

Contents Page
Foreword .iv
Introduction .vi
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
3.1 Rotary mowers . 2
3.2 Cutting elements . 3
3.3 Thrown-object testing . 4
4 Safety requirements and/or protective measures . 5
4.1 General . 5
4.2 Protection against thrown objects . 5
4.3 Protection against inadvertent contact with the cutting elements. 5
4.4 Rotating power component guarding and shielding . 5
4.5 Overrunning clutch or freewheel device . 5
4.6 Attachment means for trailed mowers . 6
4.7 Attachment means for mounted and semi-mounted mowers . 6
4.8 Cutting elements . 6
4.9 Impact of the cutting means assemblies . 6
4.10 Unbalance . 6
4.11 Structural integrity . 7
5 Verification of safety requirements and/or measures . 7
5.1 Test conditions — General . 7
5.2 Foot-probe test . 7
5.3 Impact test for cutting-element assemblies . 9
5.4 Unbalance test for the cutting element .12
5.5 Structural integrity test .13
5.6 Thrown-object test .14
5.7 Charpy impact strength test .21
5.8 Cutting-element bend test .21
6 Information for use .23
6.1 Operator’s manual.23
7 Marking and safety signs .24
7.1 Marking .24
7.2 Safety signs .24
Annex A (informative) List of significant hazards.25
Annex B (informative) Examples of test recording forms .27
Annex C (informative) Example illustrations of mowers .30
Annex D (normative) Corrugated fibreboard penetration tests .34
Bibliography .36
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ISO 4254-13:2012(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 on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 23, Tractors and machinery for agriculture and
forestry, Subcommittee SC 7, Equipment for harvesting and conservation.
ISO 4254 consists of the following parts, under the general title Agricultural machinery — Safety:
1)
— Part 1: General requirements
— Part 5: Power-driven soil-working machines
— Part 6: Sprayers and liquid fertilizer distributors
— Part 7: Combine harvesters, forage harvesters and cotton harvesters
— Part 8: Solid fertilizer distributors
— Part 9: Seed drills
— Part 10: Rotary tedders and rakes
— Part 11: Pick-up balers
— Part 12: Rotary disc and drum mowers and flail mowers
— Part 13: Large rotary mowers
— Part 14: Bale wrappers
ISO 4254-2, Tractors and machinery for agriculture and forestry — Technical means for providing safety —
Part 2: Anhydrous ammonia applicators, has been withdrawn; ISO 4254-3, Tractors and machinery for
1) For the purposes of global relevance, the requirements related to the guarding of moving parts for
power transmission have been transferred and published as two separate Technical Specifications: ISO/TS
28923, Agricultural machinery — Guards for moving parts of power transmission — Guard opening with tool, and
ISO/TS 28923, Agricultural machinery — Guards for moving parts of power transmission — Guard opening without
tool.
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ISO 4254-13:2012(E)

agriculture and forestry — Technical means for providing safety — Part 3: Tractors, has been cancelled and
is to be replaced by ISO 26322 (all parts), Tractors for agriculture and forestry — Safety; and ISO 4254-4,
Tractors and machinery for agriculture and forestry — Technical means for providing safety —Part 4:
Forestry winches, has been cancelled and replaced by ISO 19472, Machinery for forestry — Winches —
Dimensions, performance and safety.
In this corrected version of ISO 4254-13:2012, the following corrections have been made:
a
— in Table A.1, the column title has been corrected from ISO 4254-1:2008 to ISO 4254-1:2013 and the
a
Note removed from the last row.
— in Table A.1, rows 1.7, 2.1, 2.2, 4.3 and 5.1, the cross-references in the fourth column (subclause of
ISO 4254-1) have been corrected;
— in Table A.1, rows 1.6, 1.8, 7.1, 7.2 and 9.2, the cross-references in the last column have been corrected;
— in D.2.3, the mass has been corrected from 25 kg to 25 g.
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ISO 4254-13:2012(E)

Introduction
The structure of safety standards in the field of machinery is as follows:
— type-A standards (basis safety standards) giving basic concepts, principle for design, and general
aspects that can be applied to machinery;
— type-B standards (generic safety standards) dealing with one safety aspect or one type of safeguards
that can be used across a wide range of machinery;
— type-B1 standards on particular safety aspects (e.g. safety distances, surface temperature, noise);
— type-B2 standards on safeguards (e.g. two-hand control devices, interlocking devices, pressure-
sensitive devices, guards);
— type-C standards (machinery safety standards) dealing with detailed safety requirements for a
particular machine or group of machines.
This document is a type-C standard as stated in ISO 12100:2010.
When provisions of this type-C standard are different from those which are stated in type-A or -B
standards, the provisions of this type-C standard take precedence over the provisions of the other
standards, for machines that have been designed and built according to the provisions of this type-C
standard.
The machinery concerned and the extent to which hazards, hazardous situations and events are covered
are indicated in the scope of this part of ISO 4254. These hazards are specific to large rotary mowers.
Significant hazards that are common to all agricultural machines (self-propelled ride-on, mounted,
semi-mounted and trailed) are dealt with in ISO 4254-1.
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INTERNATIONAL STANDARD ISO 4254-13:2012(E)
Agricultural machinery — Safety —
Part 13:
Large rotary mowers
1 Scope
This part of ISO 4254, when used together with ISO 4254-1, specifies the safety requirements and their
verification for the design and construction of towed, semi-mounted, or mounted large rotary mowers
with single or multiple cutting elements which have a cutting diameter of 1 000 mm or greater for any
single cutting element assembly, mounted on a propelling tractor or machine, intended for agricultural
mowing equipment and designed for shredding crop residue, grass and small brush by impact.
It describes methods for the elimination or reduction of hazards arising from the intended use and
reasonable foreseeable misuse of these machines by one person (the operator) in the course of normal
operation and service. In addition, it specifies the type of information on safe working practices to be
provided by the manufacturer.
NOTE 1 These machines can be used for shredding grass. When used outside agriculture, additional
requirements not specified in this part of ISO 4254 can be applicable.
This part of ISO 4254 is not applicable to:
— rotary disc mowers, rotary drum mowers, and flail mowers designed for forage crop harvesting as
covered by ISO 4254-12;
— arm-type large rotary mowers.
— pedestrian-controlled motor mowers;
— lawn mowers covered by ISO 5395.
When requirements of this part of ISO 4254 are different from those which are stated in ISO 4254-1, the
requirements of this part of ISO 4254 take precedence over the provisions of ISO 4254-1 for machines
that have been designed and built according to the provisions of this part of ISO 4254.
This part of ISO 4254, taken together with ISO 4254-1, deals with all the significant hazards, hazardous
situations and events relevant to large rotary mowers used as intended and under the conditions
foreseen by the manufacturer. (A list of significant hazards is provided in Annex A.)
NOTE 2 Example illustrations of two mowers (a rigid-deck large rotary mower and a trail-type multi-section
foldable-wing large rotary mower) dealt with in this part of ISO 4254 are shown in C.1.
NOTE 3 Example illustrations of mowers not dealt with in this part of ISO 4254 are shown in C.2.
This part of ISO 4254 is not applicable to environmental hazards, road safety, electromagnetic
compatibility, vibration and hazards related to moving parts for power transmission. It is also not
applicable to hazards related to maintenance or repairs to be carried out by professional service
personnel.
NOTE 4 ISO 14982 specifies test methods and acceptance criteria for evaluating the electromagnetic
compatibility of all kinds of mobile agricultural machinery.
This part of ISO 4254 is not applicable to large rotary mowers which are manufactured before the date
of publication of this document by ISO.
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ISO 4254-13:2012(E)

2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 148-1:2009, Metallic materials — Charpy pendulum impact test — Part 1: Test method
ISO 730:2009, Agricultural wheeled tractors — Rear-mounted three-point linkage — Categories 1N, 1, 2N,
2, 3N, 3, 4N and 4
ISO 3600:1996, Tractors, machinery for agriculture and forestry, powered lawn and garden equipment —
Operator’s manuals — Content and presentation
ISO 4254-1, Agricultural machinery — Safety — Part 1: General requirements
ISO 4254-12:2012, Agricultural machinery — Safety — Part 12: Rotary disc and drum mowers and flail
mowers
ISO 5673-1:2005, Agricultural tractors and machinery — Power take-off drive shafts and power-input
connection — Part 1: General manufacturing and safety requirements
ISO 6508-1:2005, Metallic materials — Rockwell hardness test — Part 1: Test method (scales A, B, C, D, E,
F, G, H, K, N, T)
ISO 11684:1995, Tractors, machinery for agriculture and forestry, powered lawn and garden equipment —
Safety signs and hazard pictorials — General principles
ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk reduction
ISO 13857:2008, Safety of machinery — Safety distances to prevent hazard zones being reached by upper
and lower limbs
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4254-1, ISO 4254-12, ISO 12100,
and the following apply.
3.1 Rotary mowers
3.1.1
large rotary mower
mower, which may include mulching, with single or multiple cutting-element assemblies which have
a cutting diameter of 1 000 mm or greater powered by a propelling machine in which one or more
functional components rotate(s) about a vertical axis to cut or shear crop residue, grass and small brush
by impact
3.1.1.1
rigid-deck large rotary mowers
large rotary mowers with single or multiple cutting-element assemblies on a common rigid deck
3.1.1.2
multi-section, foldable-wing large rotary mowers
large rotary mowers with multiple cutting-element assemblies and with a single wing or multiple wings
that are capable of following the terrain
Note 1 to entry: The wings are foldable for transport and to clear obstacles, but are intended to operate only with
all sections in close proximity to the ground surface when mowing.
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ISO 4254-13:2012(E)

3.2 Cutting elements
3.2.1
cutting element
mower tool designed to cut or shear crop residue, grass and small brush by impact
Note 1 to entry: This can include mulching.
Note 2 to entry: Knives, blades and sickles are common cutting elements.
3.2.2
cutting-element lot
determined by the cutting-element manufacturer, traceable to the mill heat and manufacturing process
Note 1 to entry: A new cutting-element lot is established when there is a change in the heat of steel.
3.2.3
heat of steel
metal produced by a single cycle of a batch-melting process
Note 1 to entry: The heat analysis is obtained from a small sample of molten metal from the ladle or furnace. The
sample is allowed to solidify, then, a spectrochemical analysis is performed. If the chemical analysis is within
specification, the balance of molten metal can be cast as one heat treat number. Typically, heats are over 50 t with
many mills running heats about 300 t.
3.2.4
permanent set angle
angle formed by the back of the cutting element or test coupon in the area of the bend after removal from
the cutting-element bend-test fixture
Note 1 to entry: See Figure 1.
Key
1 permanent set angle
Figure 1 — Permanent set angle of cutting element after the bend test
3.2.5
total deflection angle
sum of the permanent set angle and the estimated spring back
Note 1 to entry: This angle is for ease of fixture design and not acceptance criteria. (See 5.8, Table 1.)
3.2.6
test coupon
flat specimen with the same cross-section and of the same cutting-element lot as the cutting elements
it represents
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ISO 4254-13:2012(E)

3.3 Thrown-object testing
3.3.1
normal operating position
space within the operator zone occupied by the operator while operating the mower
Note 1 to entry: The operator is sitting on the seat of the propelling machine with hands on the steering controls
and feet on controls or areas provided for foot placement.
Note 2 to entry: For examples of target configurations, see Figures 7 and 8.
3.3.2
projectile impact
rupture of the front layer but not the back layer of the target material by a test projectile
3.3.3
projectile hit
rupture of all layers of the target material by a test projectile
3.3.4
target material
material used for the thrown-object test
Note 1 to entry: See Annex D.
3.3.5
test projectile
common steel nail or steel wire with the approximate dimensions shown in Figure 2
Note 1 to entry: The wire projectile should be capable of bending 180° with no cracks or breaks.
Dimensions in millimetres
a) Criteria for nail projectile b) Criteria for wire projectile
Figure 2 — Test projectile
3.3.6
operator zone
space within the target area in which operator is seated in the normal operating position on the
propelling machine while operating the mower
Note 1 to entry: See Figures 7 and 8.
3.3.7
target walls
arrangement of target material and supports
Note 1 to entry: See the cross-section in Figure 9 with the configuration shown in Figures 7 and 8.
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ISO 4254-13:2012(E)

4 Safety requirements and/or protective measures
4.1 General
4.1.1 Machinery shall comply with the safety requirements and/or protective measures of Clauses 4
and 5. Machinery shall meet the test requirements and acceptance criteria as specified in 5.3, 5.4 and 5.5.
In addition, the machine shall be designed according to the principles of ISO 12100:2010 for relevant but
not significant hazards which are not dealt with by this document.
4.1.2 Unless otherwise specified in this part of ISO 4254, the machine shall comply with the requirements
of ISO 4254-1 and with Tables 1, 3, 4 and 6 of ISO 13857:2008.
4.1.3 The maximum tip speed for the cutting elements shall not exceed 96,5 m/s.
4.2 Protection against thrown objects
The mower shall be designed to minimize thrown objects so that tests defined in 5.6 are satisfied.
Protective devices (e.g. protective skirts, chains or rubber strips) may be used.
4.3 Protection against inadvertent contact with the cutting elements
4.3.1 The mower shall be designed or guarded in such a way that any inadvertent contact with the
cutting elements at the sides and on the top is prevented when the mower is operated according to the
manufacturer’s instructions in the operator’s manual.
4.3.2 The mower shall be designed or guarded in such a way that any inadvertent contact with the
cutting elements at the front (normally the intake) and at the rear (normally the exhaust) is minimized
when the mower is operated according to the manufacturer’s instructions in the operator’s manual.
4.3.3 The top protection shall be achieved by a rigid guard or by the device used to prevent thrown-
objects.
4.3.4 At the sides, at the front (intake area) and at the rear (exhaust area), there shall be protection
by rigid or flexible guard; the device used to minimize projections; or a combination of these devices so
when tested according to 5.2, there will be no contact between the test probe and the cutting element or
the cutting-element assembly.
4.4 Rotating power component guarding and shielding
4.4.1 The mower shall be designed or guarded in such a way that any inadvertent contact with the
rotating power component is minimized when the mower is operated according to the manufacturer’s
instructions in the operator’s manual.
4.4.2 Drive shafts and their connecting points shall be guarded in accordance with ISO 5673-1:2005.
Other moving parts for power transmission shall be guarded against contact to comply with the safety
distances of Tables 1, 3, 4 and 6 of ISO 13857:2008.
4.5 Overrunning clutch or freewheel device
4.5.1 Mowers equipped with an overrunning clutch or a free-wheel device shall be guarded as described
in 4.4.
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ISO 4254-13:2012(E)

4.5.2 Rotating elements that can be inadvertently contacted shall have evidence of rotation and a
suitable safety sign to warn of the hazard.
4.5.3 There shall be instructions in the instruction handbook stating to wait until all movement is
stopped before servicing.
4.6 Attachment means for trailed mowers
Any trailed unit shall be designed in such a manner that there is a remaining downward load of 3 % of
the total weight, or at least 500 N on the hitch point, in order to avoid an uncontrolled upward movement
when it is disconnected.
4.7 Attachment means for mounted and semi-mounted mowers
Three-point hitch-mounted and semi-mounted mowers shall be attached to the propelling machine by
means of one or a combination of the standardized attachment methods as defined in ISO 730:2009.
4.8 Cutting elements
4.8.1 Cutting-element identification and marking
Every cutting element shall include the following information, stamped or otherwise permanently
affixed, in a non-critical-stress area that will be readable on a used cutting element:
— cutting-element manufacturer identification;
— date of manufacture or lot number or production run number.
4.8.2 Hardness
The Rockwell hardness value shall be at least 38 HRC in accordance with ISO 6508-1:2005.
4.8.3 Charpy impact strength
The cutting element shall have an average Charpy value of at least 20,3 J when tested according to 5.7.
4.8.4 Bending
The cutting element shall not have any cracks visible to the naked eye after being submitted to the bend
test in 5.8.
4.9 Impact of the cutting means assemblies
4.9.1 The mower shall withstand a sudden impact to the cutting means.
4.9.2 Compliance is checked by conducting the test in 5.3 without loss of any part of the mower or
failure of any mower component, excluding portions of the cutting element with a mass of 30 g or less, in
a manner that can be hazardous to the operator or bystanders. There shall be no punctures made in the
target walls by any part of the mower or cutting elements.
4.10 Unbalance
The mower shall withstand unbalanced cutting means. No part of the mower shall loosen, break up or
be ejected, if they are necessary for compliance with the requirements of this part of ISO 4254, nor shall
any other component or part of the mower, puncture all the target walls, when tested in accordance with
5.4.
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ISO 4254-13:2012(E)

4.11 Structural integrity
4.11.1 The cutting means assemblies shall withstand the impact stresses to which they are subjected
when used.
4.11.2 The top or side deck shall be designed with a mild carbon steel material of 3 mm thickness or
more.
4.11.3 For other materials, and for materials < 3 mm thick, compliance is checked by conducting the
test in 5.5. There shall be no break-through of test rods through the cutting-element housing or cutting-
element enclosure and there shall be no failure of other shielding.
5 Verification of safety requirements and/or measures
5.1 Test conditions — General
5.1.1 Assembly
5.1.1.1 The mower shall be completely assembled and mounted on, or attached to, its propelling
machine except for tests where mounting on a suitable test fixture is designated; or, where necessary, the
mower unit may be tested while separated from the power unit and power be provided by some other
means. However, the speeds shall be the same as those attained when on, or attached to, the propelling
machine, and the fixed parts of the mower which extend into the trajectory area shall also be duplicated
as nearly as practicable.
5.1.1.2 Adjustable guards shall be set in the most open position for the test.
5.1.2 Mower position
Th
...