Machine Safety
Chapter 296-806, WAC |
Effective
Date: 01/01/05 |
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- In addition to the requirements in this
section, you need to refer to the following sections of
this chapter in order to fully protect your employees
from machine hazards:
- You need to refer to Portable
Power Tools, Chapter
296-807 WAC, for requirements relating to hand-held
abrasive wheel tools.
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This section applies to machines that aren't
hand-held and that use an abrasive wheel.
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Exemption:
This rule doesn't apply to natural sandstone
wheels and metal, wooden, cloth or paper discs having a
layer of abrasive on the surface.
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Definition:
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Helpful Tool:
Abrasive
Wheels Illustrations
You can find illustrations of various
types of abrasive wheels in the Resources section of this
chapter. |
Your Responsibility
To make sure abrasive wheel machines and
wheels are safe to use
You must
WAC 296-806-40502
Make sure abrasive wheels and machines are
properly designed and constructed
You must
- Make sure abrasive wheels and machines,
including safety guards and flanges, manufactured on or after
January 1, 2005, meet the design and construction requirements
of American National Standards Institute (ANSI) B7.1-2000, Safety
Requirements for the Use, Care and Protection of Abrasive Wheels.
- Make sure abrasive wheels and machines,
including safety guards and flanges, manufactured before January
1, 2005, meet the design and construction requirements of American
National Standards Institute (ANSI) B7.1-1970, Safety Code
for the Use, Care and Protection of Abrasive Wheels.
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Note:
- There may be a statement on the machine
or in the instruction manual that the machine meets the
appropriate ANSI standard. If in doubt, check with the
manufacturer.
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WAC 296-806-40504
Make sure machines have safety guards
You must
- Use abrasive wheels only on machines
that have safety guards.
- Make sure the safety guard:
- – Is mounted so it maintains proper
alignment with the wheel
- – Is mounted with fasteners strong
enough to keep the guard in position if a wheel breaks
- – Covers the
spindle end, nut, and flange projections.
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Exemption:
- Safety guards aren't required on machines
that use:
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WAC 296-806-40506
Make sure safety guards meet specific requirements
You must
- Make sure the machine safety guards meet
the requirements of Table 405-1, Guard
Requirements.
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Definition:
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Note:
- The maximum exposure angle is
measured by lines starting at the center of the
spindle and extending to the ends of the guard at
the wheel periphery.
- Visors and other accessory equipment
are used in determining the size of the guard opening
only if they're at least as strong as the safety
guard.
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WAC
296-806-40508
Provide a tongue guard on bench,
pedestal, floorstand, and cylindrical grinders
You must
- Make sure, if the operator stands in front
of the opening in the safety guard, that the safety guard (tongue
guard) at the top of the opening is adjusted to within ¼
inch of the wheel.
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Definition:
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WAC 296-806-40510
Use a work rest for off-hand
grinding
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Exemption:
- You don't need to use a work rest if:
- – The size, shape, weight
or finishing area of the workpiece prevents its use
or
- – Contact with the grinding
wheel below the horizontal plane of the spindle is
necessary
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You must
- Use a work rest to support the work.
- Make sure the work rest is:
- – Rigidly constructed
- – Adjustable to compensate for wheel
wear
- – Adjusted only when the wheel is
stopped
- – Securely clamped after each adjustment
- – Kept within 1/8
inch of the wheel
WAC
296-806-40512
Make sure abrasive wheels are
safe to use
You must
- Do the following before mounting a wheel:
- – Visually inspect the wheel for
cracks or damage
- – Perform a ring test for cracks
if the size and shape of the wheel permits testing
- – Make sure the spindle speed of
the machine isn't greater than the operating speed of the
wheel
- Make sure a damaged or cracked wheel isn't
mounted or used.
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Note:
- Wheels that have gouges, grooves,
other damage, or material buildup on the grinding surface
need to be dressed or trued to correct the problem. Wheels
that can't be trued are considered damaged and can't be
used.
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Helpful Tool:
- You can find information about how
to perform a ring test
in the Resources section of this chapter.
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WAC 296-806-40514
Mount wheels properly
You must
1) Make sure wheels fit freely on
the spindle, wheel sleeves, or adaptors, and remain free under
all grinding conditions.
2) Make sure wheel, blotter and flange surfaces
that contact each other are flat and free of foreign particles.
3) Make sure any reducing bushing used in
the wheel hole:
- Fits freely on the spindle and maintains
proper clearance
and
- Doesn't exceed the width of the wheel or
contact the flanges
4) Make sure that multiple wheels mounted
between a single set of flanges are either:
- Cemented together
or
- Separated by spacers that have a diameter
and bearing surface that's the same as the mounting flanges
WAC 296-806-40516
Use proper flanges
You must
- Mount all abrasive wheels between flanges
that have a diameter at least 1/3 the diameter of the wheel.
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Exemption:
- This flange requirement doesn't apply
to the following wheels:
- – Mounted wheels (wheels permanently
bonded to a shaft or mandrel)
- – Abrasive disc wheels (inserted
nut, inserted washer and projecting stud type)
- – Plate mounted wheels
- – Cylinder, cup, or segmental
wheels mounted in chucks
- – Types 27, 28, and 29 wheels
- – Internal wheels less than
2 inches in diameter
- – Modified Type 6 and 11
wheels (Terrazzo)
- – Types 1 and 27A cutting-off
wheel
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You must
- Make sure flanges are:
- – Dimensionally accurate
- – Properly balanced
- – Flat
- – Free of rough surfaces or sharp
edges
- Make sure the driving flange is:
- – Part of the spindle
or
- – Securely
fastened to the spindle
- Make sure, if a wheel is mounted between
two flanges, that both flanges:
- – Are the same diameter
and
- – Have equal bearing surfaces
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Exemption:
- The following wheels don't require
same diameter, equal bearing surface flanges:
- – Types 27, 28, and 29 wheels
with adaptors
- – Modified Types 6 and 11
wheels with tapered K dimension
- – Internal wheels less than
2 inches in diameter
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WAC
296-806-40518
Make sure flanges are in good condition
You must
- Make sure flange bearing surfaces are
in good condition.
- Replace or remachine a flange with a mounting
surface that has any of the following problems:
- – Warped
- – Burred on the bearing surface
- – Excessively worn (thickness or
diameter)
- – Out of true
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Reference:
- Flanges that are refaced or trued
need to satisfy minimum dimension requirements specified
in Safety Requirements for the Use, Care and Protection
of Abrasive Wheels, ANSI B7.1-2000.
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WAC 296-806-40520
Use specific flanges for Type 1 cutting-off
wheels
You must
- Mount Type 1 cutting-off wheels between flanges
that are:
- – Properly relieved with matching
bearing surfaces
- – At least ¼ the wheel diameter
WAC 296-806-40522
Use specific flanges for Type 27A cutting-off
wheels
You must
- Mount Type 27A cutting-off wheels between
flanges that are:
- – Flat (unrelieved) with matching
bearing surfaces
and
- – At least ¼ the wheel diameter
WAC 296-806-40524
Use blotters when required
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Exemption:
- You don't need to use a blotter with
any of the following:
- – Mounted wheels (wheels permanently
bonded to a shaft or mandrel)
- – Abrasive disc and Type
2 wheels which are mounted by inserted nuts, inserted
washers, or projecting studs
- – Plate mounted wheels
- – Wheels mounted in chucks
(such as cylinders and segmental wheels)
- – Types 27, 28, and 29 wheels
- – Type 1 and Type 27A cutting-off
wheels
- – Internal wheels less than
2 inches in diameter
- – Diamond and cubic boron
nitride wheels with metal or carbon fiber cores
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You must
- Use a blotter between each flange and
the abrasive wheel surface to uniformly distribute flange pressure.
- Make sure the blotter covers the entire flange
contact area.
- Use a new blotter each time a wheel is mounted
unless the wheel has a blotter already attached to it by the
manufacturer.
- Make sure scuffed or damaged blotters aren't
used.
WAC 296-806-40526
Meet specific blotter requirements when
using modified Types 6 and 11 wheels (terrazzo)
You must
- Apply the blotter to the flat side
only when mounting Modified Types 6 and 11 wheels (terrazzo).
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