Machine SafetyChapter 296-806, WAC |
Effective Date: 01/01/05 |
Mechanical Power Presses |
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This section applies to mechanically powered machines that transmit force to cut, form, or assemble metal or other materials through tools or dies attached to or operated by slides.
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Your Responsibility
To make sure mechanical power presses meet the requirements of this section
You must
| DESIGN AND CONSTRUCTION | |
| Make sure mechanical power presses are properly designed and constructed |
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| SAFEGUARDING | |
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Safeguard presses that use unitized tooling |
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Protect operators from guidepost hazards |
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Safeguard the point of operation |
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| Make sure point-of-operation guards are properly designed and constructed |
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| Make sure barrier guards used to safeguard the point of operation meet these requirements |
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| Make sure point-of-operation devices are effective |
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| Make sure presence-sensing devices used to safeguard the point of operation meet these requirements |
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| Make sure pull-back devices used to safeguard the point of operation meet these requirements |
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sure restraint (holdout) devices used to safeguard the point
of operation meet these requirements |
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| Make
sure two-hand control devices used to safeguard the point
of operation meet these requirements |
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| Make
sure two-hand trip devices used to safeguard the point of
operation meet these requirements |
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| Provide
additional safeguards when the operator puts one or both
hands into the point of operation |
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| OPERATIONS | |
| Establish die setting procedures |
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| Handle dies safely |
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| Protect die setters during setup and tryout |
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| Train press operators |
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| Operate mechanical power presses safely |
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| Provide tools and other means to protect press operators |
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| Inspect and maintain presses |
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| Make
sure presses and operating practices used in the PSDI mode
of operation meet these requirements |
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DESIGN AND CONSTRUCTION
Make sure mechanical power presses are properly designed and constructed
You must
- Make sure mechanical power presses manufactured before January 1, 2005, meet the requirements of American National Standards Institute (ANSI) B11.1-1971, Safety Requirements for the Construction, Care, and Use of Mechanical Power Presses.
- Make sure mechanical power presses manufactured, reconstructed, or modified on or after January 1, 2005, meet the requirements of ANSI B11.1-2001, Safety Requirements for Mechanical Power Presses.
SAFEGUARDING
Safeguard presses that use unitized tooling
You must
- Safeguard the opening between the top of the punch holder and the face of the slide or striking pad by using properly installed, adjusted, and maintained guards or devices.
Protect operators from guidepost hazards
You must
- Use properly installed, adjusted, and maintained
guards or devices to protect operators from the hazards created
by:
- – Guideposts separating from their bushings
- – Similar pinch points between the slide (moving die) and fixed die or press attachments

- This requirement doesn't apply if the opening is ¼ inch or less, before use.
Safeguard the point of operation
You must
- Protect employees from point-of-operation hazards by using properly installed, adjusted, and maintained guards or devices.
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Note:
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Make sure point-of-operation guards are properly designed and constructed
You must
- Make sure each guard:
- – Prevents the operator’s hands or other body parts from reaching through, over, under, or around the guard into the point of operation.
- – Has no opening larger than the
maximum permissible openings shown in
Table 200-1, Largest Allowable Guard Openings, WAC 296-806-20042. - – Doesn't create a pinch point between the guard and moving machine parts.
- – Uses fasteners that can't be easily removed by the operator.
- – Is easy to inspect.
- – Provides the best view of the point of operation for the type of work.
Make sure barrier guards meet these requirements
You must
- Make sure a fixed barrier guard is attached to a fixed surface such as the stripper, die shoe, press frame, or bolster plate.
- Make sure the interlocked barrier guard:
- – Is attached to a fixed surface such as the press frame or bolster plate
- – Prevents cycling (stroking) of the press when the interlocked section of the guard isn't in the protecting position
- – Can't open until hazardous motion of the slide has stopped
- Not use the hinged or movable sections of an interlocked barrier guard for manual feeding.
- Make sure an adjustable barrier guard is:
- – Attached to a fixed surface such as the press frame, bolster plate, or die shoe
- – Adjusted only by authorized persons who can apply Table 200-1, Largest Allowable Guard Openings, WAC 296-806-20042.

- See, Provide additional safeguards when the operator puts one or both hands into the point of operation, WAC 296-806-45526, for additional safeguards that are required if the operator puts one or both hands into the point of operation to feed or remove parts, and the point of operation is protected by a Type B gate or movable barrier device.
Make sure point-of-operation devices are effective
You must
- Make sure point-of-operation devices protect the operator from hazards as shown in Table 455-1, Point-of-Operation Devices.
- Make sure the motor start button is protected against accidental contact.
Table
455-1
Point-of-Operation Devices
| Type of Device |
Type of Operator protection that must be provided |
| Presence-sensing device (part-revolution clutch press) | If the operator’s hands or other
body part are in the point of operation: • Prevents initiating a press cycle (stroke) or • Stops the press during the closing portion of the cycle (stroke) |
| Presence-sensing device (full-revolution clutch press) | Do not use for point-of-operation safeguarding |
| Pull-back device | As the die closes: • Withdraws the operator’s hands if they are located in the point of operation or • Prevents the operator from reaching into the point of operation |
| Restraint (holdout) device | Prevents the operator from reaching into the point of operation at all times |
| Two-hand control device Two-hand trip device |
• Requires operators to use both hands to activate controls that are far enough away from the point of operation so the slide completes the closing portion of the cycle (stroke) or stops before they can reach into the point of operation |
| Type A gate or movable barrier device | Encloses the point of operation: • Before a press cycle (stroke) can be initiated and • Remains closed until slide motion has stopped |
| Type B gate or movable barrier device | Encloses the point of operation: • Before a press cycle (stroke) can be initiated and • Remains closed until slide motion has stopped during the closing portion of the cycle (stroke) |
| Sweep device | Do not use for point-of-operation safeguarding |
Make sure presence-sensing devices used to safeguard the point of operation meet these requirements
You must
- Make sure the presence-sensing device is interlocked into the control circuit to prevent or stop slide motion if the operator’s hand or other body part is within the sensing field of the device during the down stroke of the press slide.
- Make sure muting of the device is done only during the upstroke of the press slide.
- Make sure failure of any
component of the device:
- – Doesn't prevent normal stopping action of the press
- – Prevents initiation of another cycle (stroke) until corrected
- – Is indicated by the system
- Use guards to protect all areas of entry to the point of operation not protected by the presence-sensing device.
- Make sure the sensing field of the device
is located farther from the point of operation than the minimum
safety distance as determined by the following formula:
D = 63 X T
Where:
D = minimum safety distance (in inches)
T = stopping time of the press measured at approximately the 90 degree position of crankshaft rotation (in seconds)
Example:
The number in the formula represents the hand speed of the operator
(63 inches per second). If your press has a stopping time of 1/2
seconds (.5 seconds), the calculations would be:
D = 63 X .5 = 31.5
The sensing field would need to be at least
31-½ inches from the point of operation.
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Make sure pull-back devices used to safeguard the point of operation meet these requirements
You must
- Make sure presses requiring more that one operator have a separate pull-back device for each operator.
- Make sure each pull-back device has attachments:
- – For each of the operator’s hands
- – That are connected to and operated only by the press slide or its attached die
- – That are adjusted to either:
- Prevent the operator from reaching
into the point of operation
or - Withdraw the operator’s hands from the point of operation before the dies close
- Prevent the operator from reaching
into the point of operation
- Check each pull-back device that's being
used for proper adjustment at these times:
- – At the start of each operator shift
- – After a new die set-up
- – When operators are changed
- Complete necessary maintenance or repair work before operating the press.
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Make sure restraint (holdout) devices used to safeguard the point of operation meet these requirements
You must
- Make sure presses requiring more than one operator have separate restraint devices for each operator.
- Make sure each restraint device has attachments:
- – For each of the operator’s hands
- – That are securely anchored
- – That are adjusted so the operator can't reach into the point of operation
Make sure two-hand control devices used to safeguard the point of operation meet these requirements
You must
- Make sure presses that require more than
one operator:
- – Have separate two-hand controls for each operator
- – Need concurrent application of all operators’ controls to activate the slide
- Make sure the slide stops if any operator’s hand's removed from a control button.
- Make sure two-hand controls are fixed in position and can be moved only by authorized persons.
- Make sure the controls are located farther
from the point of operation than the minimum safety distance
as determined by the following formula:
D = 63 X T
Where:
D = minimum safety distance (in inches)
T = stopping time of the press measured at approximately the 90 degree position of crankshaft rotation (in seconds)
Example:
The number in the formula represents the hand speed of the operator
(63 inches per second). If your press has a stopping time of 1/2
second (.5 second), the calculations would be:
D = 63 X .5 = 31.5
The controls would need to be at least 31½ inches from the point of operation.
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Make sure two-hand trip devices used to safeguard the point of operation meet these requirements
You must
- Make sure presses requiring more than one
operator:
- – Have separate two-hand trips for each operator
- – Need concurrent application of all operators’ controls to activate the slide
- Make sure the two-hand trips are fixed in position and can be moved only by authorized persons.
- Make sure the controls are located farther
from the point of operation than the minimum safety distance
as determined by the following formula:
D = 63 X T
Where:
D = minimum safety distance (in inches)
T = the maximum time the press takes for the die to close after the press has been tripped (in seconds)
Example:
The number in the formula represents the hand speed of the operator
(63 inches per second). If your press has a die closing time of
1/2 second (.5 second), the calculations would be:
D = 63 X .5 = 31.5
The trip device would need to be at least
31½ inches from the point of operation.
Provide additional safeguards when the operator puts one or both hands into the point of operation
IMPORTANT:
- This rule applies when the operator puts
one or both hands into the point of operation to feed or remove
parts, and the point of operation is protected by any
of the following:
- – Presence-sensing device
- – Two-hand control
- – Type B gate or movable barrier device
You must
- Make sure the press has both a:
- – Stopping-performance monitor (previously
called brake-system monitor)
and - – Control system that monitors the performance of safety-related functions (previously called control reliability)
- – Stopping-performance monitor (previously
called brake-system monitor)
- Make sure the stopping-performance monitor
meets the requirements of:
- – American National Standards Institute (ANSI) B11.1-1982, Mechanical Power Presses - Safety Requirements for Construction, Care, and Use for presses manufactured before January 1, 2005
- – ANSI B11.1-2001, Safety Requirements for Mechanical Power Presses for presses manufactured on or after January 1, 2005
- Make sure the control system monitors the
performance of safety-related functions so that failure of any
component in the control system:
- – Doesn't prevent normal stopping action of the press
- – Prevents initiation of another cycle (stroke) until the failure is corrected
- – Can be detected by a simple test or is indicated by the control system

- This requirement doesn't apply to control system components that don't affect protection from point-of-operation hazards.

- The control system includes the sensors, manual input and mode selection elements, interlocking and decision-making circuitry, and output elements of the press-operating devices and mechanisms.
