Safety Principles for
All the publications in the Publications Archive
contain the best guidance available at the time of
publishing. However, you should consider the
effect of any changes to the law since then. You
should also check that the Standards referred to
are still current.
Accident Causes 5
Requirement of Machinery Act 1950 6
Prime Mover and Transmission 6
Dangerous Parts — Blade and Clamp 6
Manual or Treadle Operated Machines 7
Power-Operated Machines 9
Back Guard 17
Guard Design 20
Other Publications 21
It has been recognised for a number of years that the guillotine is a dangerous
machine when used in an unguarded state and therefore the object of this booklet is
to illustrate types of guards for metal cutting guillotines used throughout the engineer-
ing industry and machines of similar character used in other industries.
In issuing this booklet opportunity has been taken to illustrate not only conventional
methods of guarding but also to show how methods of aiding production such as
mechanical handling can be contrived to promote as well as facilitate tidiness and
general good industrial housekeeping.
The booklet recognises the dangerous character of the guillotine blade whetherit is
operated by foot or by power.
The Department of Labour appreciates the assistance given by both industry and
manufacturers in the preparation of the contents of this booklet which has the support
and agreement of industry.
(c) Strip cutting.
(a) Plain cutting
Three types of cutting are done with guillotines:
be the loss of only one finger tip or it may be the loss of all the fingers of one hand.
that do occur on guillotines are serious and involve some degree of mutilation. It may
high. But what can be said with reasonable certainty is that the majority of accidents
total number of injuries from all causes, the number of guillotine accidents is not very
It is probable that in relation to the number of guillotines in use or in relation to the
have a severity which is out of all proportion to their frequency.
Accidents on guillotines like those on power presses and similar types of machinery,
shears, or billet shears.
substances, but for the purpose of this booklet does not include alligator shears, bar
or bevel-edged blade operating vertically against resisting edges used for shearing
The term “metal cutting guillotine” means a machine usually equipped with a square
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hope that designers and users will be stimulated to further development.
guarding; rather it is put forward in order to show what has been done, and in the
The information given is not intended to be the last word on the subject of guillotine
the metal trades industry, have application to these.
illustrated in figure 1 and the examples of guarding shown, while drawn mainly from
however machines of similar character used in other industries for cutting materials
The metal cutting guillotine is used mainly in the engineering industry. There are
HIVE During strip cutting, particularly the cutting of strip in series where an attempt is made
to keep the percentage of waste as low as possible, the operator is inclined to put his
hands as close to the blade as he can. This increases the risk of injury.
A Clamps are usually employed on power-operated guillotines and unless the stroke of
the clamp is so small as to preclude the entry of the fingers below the clamp injuries
Many accidents have also occurred when work is being fed from the back of the
machine. Guillotines are intended to be worked from the front. However, it has been
found that, on repetition work to fine limits, the work can be more easily done by a
person feeding the sheet from the back to a front stop; the cut pieces being removed
by an operator at the front. This is a particularly hazardous method of working
because the person at the rear may be out of sight whilst manipulating work close to
the blade and inadvertent engagement of the clutch or power control by the operator
in front may result in a serious accident.
Accidents have also occurred where an operator has reached through the throat of
the machine to locate or position work, and has either inadvertently or with intent
engaged the clutch or power control.
Requirement of Machinery Act 1950
The MachineryAct 1950 requires that the moving parts of the prime mover, every
part of any transmission machinery, and every dangerous part of any other machinery
be securely fenced, unless the parts are in such a position or of such construction as
to be as safe to every person employed or working on the premises as they would
be if securely fenced.
These requirements can be met in respect of metal cutting guillotines by:
(a) Complete enclosure of the prime mover and transmission.
(b) Fitting a guard which will prevent a worker from coming into contact with the
blade or clamp when the machine is in motion.
Prime Mover and Transmission
The prime mover of the individual electric motor type is usually completely enclosed
except for the shaft end on to which the transmission pulley is secured. Good design
of the guard for the transmission will ensure enclosure of the shaft end as well as the
The transmission should be securely fenced in terms of the Department’s leaflet
Guarding Transmission Machinery.
Dangerous Parts — Blade and Clamp
The dangerous character of guillotine blades, whether operated by foot or by power,
has long been recognised, and the need for effective guarding is clear. For most
purposes and especially in the case of finished flat sheet a static fixed guard can and
should be used in preference to any other type.
Manual or Treadle Operated Machines
For the simple treadle guillotine without clamp, the fixed guard should be set close to
the blade so as to prevent the finger tips of the operator reaching the blade. Care
should be taken to see that the guard is arranged to prevent access over the top and
also at the ends.
The guard will also he effective from the back of the machine if it is set vertically, in
rubbing contact with the blade and sothat the feed opening extends to no more than
6 mm above the table. If the bottom edge of the guard is chamfered it will assist
This principle of a fixed guard applied to a treadle or light power operated guillotine
without clamp is illustrated in figures 2 and 3. The guard A is a plate supported on
the rail B and held in contact with the blade by set screw C at each end. The gap
between the underside of the guard and the table Another method of providing a
fixed guard for a treadle is 6 mm and, provided care is taken that the guard is
maintained in contact with the blade, it should not be possible for the fingers to pass
between the blade and approached from the front or back.
Another method of providing a fixed guard for a treadle-operated guillotine without
clamp is shown in figure 4. The front guard is set at an angle to provide for sighting
the work. This is necessary when cutting to a line. A simple form of back guard is
Figures 5 and 6 show yet another method of guarding the back of a treadle guillotine.
The guard provides a feed opening for stock and a lower opening with deflector
plate for cut pieces which are pushed off the table beneath the front guard.
On some designs of treadle operated guillotines clamps are provided; these clamps
are designed to come into operation as the treadle is depressed. They secure the
material and also provide a guard to the blade as they arc usually positioned at a
maximum distance of 6 mm above the table.
However, many manufacturers destroy its use as a guard by adopting multi-point
contacts intended to ensure that the material is firmly gripped. These multi-point
contacts are provided by shaping the clamp as shown in figure 7 and inset A.
Accidents have occurred when an operator has extended his finger through the gaps
to hold material when cutting narrow strips. His finger has reached the blade. Inset B
shows a method of overcoming this difficulty by chamfering finger recesses in the
In order to prevent injury to the operator’s foot from the descending treadle, floor
stops should be provided. This is shown in figure 8.
As previously stated a fixed guard is practicable and should always be used in
preference to any other type of guard. However, a problem often arises because of
the wavy nature of the metal as delivered for shearing making it difficult to pass the
sheet through a narrow opening. Such a difficulty can often be dealt with by making
the feed opening in the guard sufficiently large to pass the sheet. However, it should
A be set at such a distance from the blade or clamp as to prevent finger tips from
While the effectiveness of any fixed guard must always be judged by a test to see
that the finger tips cannot reach the point of danger, the following formula is used by
the Department of Labour as a guide to the setting of a guard.
Minimum distance of guard
opening from danger point = 10 x (guard opening — 6 mm)
The relationship between guard opening and distance from the danger point is shown
in table 1 below:
Minimum clearance between Maximum width of
guard and dangerous part opening
0-25 mm 6 mm
50 mm 13 mm
100 mm 16 mm
130 mm 19 mm
160 mm 22 mm
190 mm 25 mm
220 mm 28 mm
250 mm 31 mm
For trimming operations and other cases where close access to the blade is not
necessary, a grille guard as shown in figure 9 can be effective. The outer bar, in
relation to the table, must provide a feed opening at a safe distance from the blade or
clamp so also must the spacing of each intermediate bar, see table 1.
Figure 10 shows the guarding arrangement of an electromechanical Edwards
‘’Besco-Truecut” machine fitted with a 1.8 m blade, installed at the factory of
National Radiator Ltd. Wellington. The upper portion of the front guard is set at an
angle to provide for sighting the work, and is fitted with shadowline lighting for
accurately cutting to a scribed line.
The size of this opening is 28 mm and is situated 225 mm from the nearest trapping
point and this complies with table 1. The bottom portion of the guard is situated
6 mm above the table and at a distance of 45 mm out from the clamp and 90 mm
from the blade. This again complies with table l.
Many machines are manufactured with an excessive opening at the throat (the open-
ing at each end of a guillotine used for notching and feeding material wider than the
machine table) through which an operator can reach to the back of the blade. It has
been found that although many new machines have this feature it is seldom used. In
the circumstances the blade is exposed at this point unnecessarily.
Figure 11 shows a hydraulically operated guillotine manufactured by Dye Industries
Ltd. Auckland, and shows the throat referred to, and in figure 12 the guarding
arrangements under taken by the manufacturers to overcome this hazard.
Where a throat is essential, however, access to the blade and clamp can be pre-
vented at the feeding side by a tunnel guard which forms an extension of the table
and front guard.At the delivery side where the sheared metal emerges at two
levels, a hinged guard, opened only for the slitting of large sheets can be provided.
The frontal guard shown in figure 11 is positioned at a distance of 10 mm above the
table and at a distance of 125 mm from the blade. While guards of this type give
adequate protection for both the blade and hydraulic clamps, a problem does arise
when it is required to shear narrow work close to the blade.
Figure 13 shows a Dye guillotine installed at Electrolux Ltd. Wellington, and the
method adopted to overcome this problem. The bottom portion of the guard is
arranged with recesses formed into the spaces between the hydraulic clamp feet.
This provides a safe means of controlling narrow work near to the blade. To prevent
reaching over the recess into the blade, the top of each recess is filled in with a plate
to form a roof. (The inset makes this principle clear.)
Figure 14 illustrates a further development of this principle incorporated by the
manufacturers in the latest model of the Dye guillotine.
The successful application of a fixed guard to the large plate guillotine raises prob-
lems, because of the thickness of the material being fed to the blade, and also if there
are bends in the plate.
The size of opening in such a guard would necessarily have to be large enough to
allow the plate to pass under the guard and to prevent a person reaching through the
opening to be trapped by the blade or clamp. Such an opening would require to be
at a distance corresponding to the values given in table 1.
This then would prohibit the feeding of narrow material to the blade with the guard in
To overcome this problem Dye Industries Ltd. Auckland, fit hinged interlocking
guards large plate guillotines, and figures 15 and 16 show the guarding arrangement
as fitted to the 2.4 in x 13 mm plate guillotine.
This guard consists of a steel frame to which is secured 20 mm wire mesh, which
covers the full face of the clamps and blade.
The guard is interlocked with the foot control pedal, so that when the guard is open,
as shown in figure 15, it is not possible to initiate a closing stroke of either the clamp
To operate the machine the guard must be brought down to the closed position, as
shown in figure 16, and in this position the feed opening between the bottom of the
guard and the table is 25 mm and at a distance of 300 mm from the clamps and
445 mm from the blade.
The guard linkage and interlocking arrangement are shown in figures 17 and 18.
The rod controls
the hydraulic system
Guides Lift up guard connected
Stop to interlock bar
Foot pedal control
Figure 19 shows a fixed grill guard fitted to an ordinary guillotine at Dunlop Rubber
Company’s factory in England and was used for cutting rubber floor tiling sheet of
10 mm thickness. The guard was designed on the lines of their rubber calender
guards of the loop and grill type.
In common with those guards, this guard has the same two advantages; it affords a
clear view of the dangerous operation, and it permits the use of the fingers close to
the danger point, while not affording access thereto.
The guard which is of stout construction and strongly fixed to the framing is in two
parts, A and B.A is hinged about the top shaft C, and is held in position by the bolts
which fix the brackets at the ends of the midway bar D to the frame.
When the bolts are removed, A can be swung up and back out of the way; this
affords facilities for attending to the knife when required. In order to ensure that a
power stroke cannot be initiated while the dangerous parts are exposed, this upward
movement of guard can be interlocked with the power supply by attaching a cam to
the end of shaft C. Theupward movement of guard forces open by positive means a
normally closed limit switch.
This guard can be adopted for cutting sheet or other kinds of material of moderate
Figures 20 and 21 show another method of guarding a guillotine used for cutting
rubber sheet and fitted to a pneumatically operated guillotine at Atlas Rubber Co.
A Figure 20 shows the feed-in side of the machine. A free running rubber coated roll is
placed between the bottom of the fixed guard and the table to facilitate feeding. The
feed-in space formed between the bottom of the roll and the table is 10 mm and is
positioned 50 mm from the blade.
Figure 21 shows the guarding arrangement applied to the back of the machine. This
consists of two free-running rubber coated rolls positioned 22 mm apart and
165 mm from the blade.
Figure 22 shows the guarding arrangements to the feed and discharge sides of a
guillotine used for cutting veneer at Fletcher Industries Ltd. Gladstone. In order to
facilitate the feeding of buckled veneer under the fixed guard, the guard was posi-
tionedto give an opening above the table of 38 mm at a distance from the knife of
330 mm on either side.
Accidents occur when work is being fed from the back of the machine. Guillotines
are intended to be worked from the front, but it has been found that on repetition
work to fine limits, the work can be more easily done by a person feeding the sheet
from the back to a front stop, the cut pieces being removed by an operator at the
On this method of working, two operators are required, one at the front to control
the machine, the other to feed material under the blade from the rear. Whenever a
machine is attended by more than one operator there is a danger of an accident being
caused by a misunderstanding. A word or a nod from one man may be misconstrued
by his colleague who may then set the machine in motion when a hand is in the
The design of a back guard to meet such conditions is not easy, but figures 23 and
24 show methods which can be applied. In figure 23 the guard is carried on a pair of
rocker levers with counter balance weights so that in conjunction with stopsA-A the
normal position of the feed slot, which should conform to table 1, is on the same level
as the top of the fixed blade.
In figure 24 the back guard is of the floating type and consists of a frame fitted in
guide castings. At the “high” end of the blade, the frame pivots about on pointA,
fitted in the guide casting and at the “low” end the frame is attached to the blade
A beam by a crank pin B.
The upper apron prevents trapping under the blade, and the lower apron prevents
access to the blade under the guard, and the space between should conform to
A front guard is, of course, essential under all circumstances.
When work is performed from the front only, there should nevertheless be guards at
the back of the machine and these can usually take the form of barriers or screens to
prevent a person reaching the blades.A worker may go to the back of the machine
to collect work or trimmings and stumble against the blade at a moment when it is in
Considerable importance is attached to the provisions of means for discharging the
cut material away from the back of the blade. The simplest arrangement is an inclined
skid plate. Other useful ideas illustrated are a belt conveyor in conjunction with a
collecting box and a collection box on wheels which, in association with other
guarding, could form the guard for the back.
These ideas are not only valuable for accident prevention but also promote good
housekeeping, and by helping to direct work into neat piles, render collection and
disposal more simple.
Figure 25 shows the back of the machine shown in figure 13, where the guarding of
this area has been provided by a belt conveyor which is used with a collecting box.
Back guards incorporating a container for cut work are shown in figures 26 and 27.
The container is a truck, so arranged and constructed that when in the normal posi-
tion as shown in figure 26 it prevents, with the associated fixed guarding, access to
the blade. When the truck is withdrawn to remove the cut work, the raised rear edge
prevents access to the blade. The square openings in the sloping screen are provided
for gauge adjustment and do not permit access to the blade.
Figure 28 shows a simple method of guarding the back of a guillotine by the use of
tubular guarding. The tubes, which combine lightness and strength should be suffi-
ciently generous in section to give rigidity, and the spacing should comply with the
principle of reasonable reach through openings so as to prevent a person from
reaching the blade.At the same time the guard permits access to the gauge
Figure 29 shows a back guard which is suitable where there is no feeding from the
back. The fixed back guard is arranged with an inclined plate so as to form an exit
chute for delivery of cut material.
The design of a fixed guard should meet the following requirements:
(a) The guard should prevent hand or other parts of the body from entering the
(b) The guard should be rigid and of adequate strength for the purpose.
Typical material used for fixed guards are metal rods, slotted plate, expanded metal.
Transparent plastic can also be used, but this becomes opaque after some time.
Where metal rods are used in the line of vision of the operator they should, where
practicable, be arranged vertically rather than horizontally.
Other publications showing the principles of guarding machinery used in the
engineering industry are available free of charge from any office of the Department of
Labour District offices of the Department of Labour are located at:
Whangarei Hastings Blenheim
Auckland Palmerston North Greymouth
Manukau Masterton Christchurch
Hamilton New Plymouth Timaru
Tauranga Wanganui Dunedin
Rotorua Lower Hutt Invercargill