By Mike Spain
Press brakes are unforgiving machines and a frequent cause of workplace injuries. The U.S. Department of Labor reports that press
brakes cause more than 350 amputations per year.
And those are only the reported accidents.
With such risk at stake, most would expect manufacturers to be strongly committed to press brake
safeguards, but that’s not really the case. As reported in Safety + Health magazine, a lack of machine
guarding is consistently on OSHA’s top 10 most cited
violations report, moving from No. 9 in 2015 to No.
8 in 2016.
In 2016 alone, 88 percent of the total number of
OSHA machine guarding violations were classified
as “serious,” meaning there is a substantial probability that death or serious physical harm could result and the employer knew or should have known
of the hazard.
The fines for these violations are more than $7
million each year. Of course, the actual price tag for
an injury is much higher than simply the OSHA citation. Its indirect costs must be taken into account,
such as damage to facilities or equipment, medical
expenses, lawsuits, lost productivity, and replacement personnel.
Why Are Press Brakes So Dangerous?
No matter its age, a press brake presents a unique
set of dangers. The primary dangers are access to
the point of operation at the front of the machine
(see Figure 1) and reaching around the safety device to get to the point of operation at the ends of
the machine. (In the U.S., press brake manufacturers o;en consider the point of operation to be the
end user’s responsibility and therefore do not install required guarding. In Europe, when a machine
leaves its point of manufacture, it is shipped with
the guarding already in place.) In addition, pinch
points and quick-moving backgauges also pose
risks to press brake operators.
An overview of
press brake safeguarding
The emergence of new laser-based camera vision
systems changes how fabricators can approach safety
at the point of operation
But the dangers don’t stop there. Fabricators
sometimes employ used or refurbished press brakes
on which the primary controls and the general condition of the machines and safety systems may be
suspect. Fabricators may not have anyone on sta;
that has safeguarding competency, so serious shortcomings can be overlooked or ignored. Press brakes
have always been operator-intensive, sometimes involving multiple operators, and their behavior is not
always predictable. That is why it is good practice to
make one operator the leader of the crew.
For a list of basic safety procedures, see the
Golden Rules of Press Brake Operation
The two safety codes that matter most in press
brake operation are OSHA 29 CFR 1910 and ANSI
B11.3-2012. The ANSI B11.3 standard is the far more
specific of the two. Plus, with the recent adoption of
the European 12622 standard in the latest version,
the updated B11.3 has largely removed many of the
vague parts of the original standard. U.S. standards
o;en adopt European standards to augment or clarify an existing OSHA or ANSI standard.
ANSI B11.3 is the only safety system standard specifically applicable to power press brakes used in the
U.S. It excludes mechanical power presses, hydraulic power presses, hand brakes, tangent benders,
apron brakes, and similar metal bending machines.
It discusses hazards associated with the point of operation at length and identifies alternative guards
and devices. For example, it discusses modern press
brake safeguarding concepts such as close-proximity, point-of-operation AOPD safeguarding devices
(AOPD stands for active optoelectronic protective
device) and working at safe speeds.
It should be noted that ANSI B11. TR3 recommends
risk assessments of press brakes and other equipment. Risk assessments have proven over time to
be the best and more comprehensive approach to
establish an e;ective safety system. They should
be performed when new machinery is installed, refurbished presses are put into commission, existing
machinery has been upgraded, or work processes
have changed in the bending area.
In addition, the risk assessment needs to be done
a;er an accident or serious incident as part of an
investigation. In general, it is good practice to perform a risk assessment every three years, even if no
changes have been recorded.
Basic Press Brake Protection Options
Several options are available to safeguard a press
brake. Some are better than others.
The most basic type of safeguarding is a fixed and
interlocked barrier guard coupled with two hand
controls. This is not a functional approach for fabricators as the workpiece is held in close proximity
to the point of operation during the braking process
and can potentially whip up as bending is taking
Press brake operators experience a greater risk of injury
if they are working with small parts that require them to
have their fingers close to the point of bending.