29 Cfr 1910.218

Occupational Safety and Health Admin., Labor
An acceptable method for interlocking
supplemental guards as required by paragraph (h)(6)(xiii) would be to incorporate the
supplemental guard and the PSDI presence
sensing device into a hinged arrangement in
which the alignment of the presence sensing
device serves, in effect, as the interlock. If
the supplemental guards are moved, the
presence sensing device would become misaligned and the press control would be deactivated. No extra microswitches or interlocking sensors would be required.
Paragraph (h)(6)(xv) of the standard requires that the control system have provisions for an ‘‘inch’’ operating means; that
die-setting not be done in the PSDI mode;
and that production not be done in the
‘‘inch’’ mode. It should be noted that the
sensing device would be by-passed in the
‘‘inch’’ mode. For that reason, the prohibitions against die-setting in the PSDI mode,
and against production in the ‘‘inch’’ mode
are cited to emphasize that ‘‘inch’’ operation
is of reduced safety and is not compatible
with PSDI or other production modes.
7. Environmental Requirements
It is the intent of paragraph (h)(7) that
control components be provided with inherent design protection against operating
stresses and environmental factors affecting
safety and reliability.

tion in the sensing field. A minimum object
sensitivity of one and one-fourth inches
(31.75 mm) means that a one and one-fourth
inch (31.75 mm) diameter object will be continuously detected at all locations in the
sensing field.
In deriving the safety distance required in
paragraph (h)(9)(v), all stopping time measurements should be made with clutch/brake
air pressure regulated to the press manufacturer’s recommended value for full clutch
torque capability. The stopping time measurements should be made with the heaviest
upper die that is planned for use in the press.
If the press has a slide counterbalance system, it is important that the counterbalance
be adjusted correctly for upper die weight according to the manufacturer’s instructions.
While the brake monitor setting is based on
the stopping time it actually measures, i.e.,
the normal stopping time at the top of the
stroke, it is important that the safety distance be computed from the longest stopping
time measured at any of the indicated three
downstroke stopping positions listed in the
explanation of Ts. The use in the formula of
twice the stopping time increase, Tm, allowed by the brake monitor for brake wear
allows for greater increases in the downstroke stopping time than occur in normal
stopping time at the top of the stroke.
10. Inspection and Maintenance. [Reserved]

8. Safety system
The safety system provision continues the
concept of paragraph (b)(13) that the probability of two independent failures in the
length of time required to make one press
cycle is so remote as to be a negligible risk
factor in the total array of equipment and
human factors. The emphasis is on an integrated total system including all elements
affecting point of operation safety.
It should be noted that this does not require redundancy for press components such
as structural elements, clutch/brake mechanisms, plates, etc., for which adequate reliability may be achieved by proper design,
maintenance, and inspection.
9. Safeguarding the Point of Operation

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§ 1910.218

The intent of paragraph (h)(9)(iii) is to prohibit use of mirrors to ‘‘bend’’ a single light
curtain sensing field around corners to cover
more than one side of a press. This prohibition is needed to increase the reliability of
the presence sensing device in initiating a
stroke only when the desired work motion
has been completed.
Object sensitivity describes the capability of
a presence sensing device to detect an object
in the sensing field, expressed as the linear
measurement of the smallest interruption
which can be detected at any point in the
field. Minimum object sensitivity describes
the largest acceptable size of the interrup-

11. Safety System Certification/Validation
Mandatory requirements for certification/
validation of the PSDI safety system are
provided in appendix A and appendix C to
this standard. Nonmandatory supplementary
information and guidelines relating to certification/validation of the PSDI safety system are provided to appendix B to this standard.
[39 FR 32502, June 27, 1974, as amended at 39
FR 41846, Dec. 23, 1974; 40 FR 3982, Jan. 27,
1975; 43 FR 49750, Oct. 24, 1978; 45 FR 8594,
Feb. 8, 1980; 49 FR 18295, Apr. 30, 1984; 51 FR
34561, Sept. 29, 1986; 53 FR 8353, 8358 Mar. 14,
1988; 54 FR 24333, June 7, 1989; 61 FR 9240,
Mar. 7, 1996; 69 FR 31882, June 8, 2004]

§ 1910.218

Forging machines.

(a) General requirements—(1) Use of
lead. The safety requirements of this
subparagraph apply to lead casts or
other use of lead in the forge shop or
die shop.
(i) Thermostatic control of heating
elements shall be provided to maintain
proper melting temperature and prevent overheating.
(ii) Fixed or permanent lead pot installations shall be exhausted.

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§ 1910.218

29 CFR Ch. XVII (7–1–07 Edition)

(iii) Portable units shall be used only
in areas where good, general room ventilation is provided.
(iv) Personal protective equipment
(gloves, goggles, aprons, and other
items) shall be worn.
(v) A covered container shall be provided to store dross skimmings.
(vi) Equipment shall be kept clean,
particularly from accumulations of
yellow lead oxide.
(2) Inspection and maintenance. It
shall be the responsibility of the employer to maintain all forge shop
equipment in a condition which will insure continued safe operation. This responsibility includes:
(i) Establishing periodic and regular
maintenance safety checks and keeping certification records of these inspections which include the date of inspection, the signature of the person
who performed the inspection and the
serial number, or other identifier, for
the forging machine which was inspected.
(ii) Scheduling and recording the inspection of guards and point of oper-

ation protection devices at frequent
and regular intervals. Recording of inspections shall be in the form of a certification record which includes the
date the inspection was performed, the
signature of the person who performed
the inspection and the serial number,
or other identifier, of the equipment
inspected.
(iii) Training personnel for the proper
inspection and maintenance of forging
machinery and equipment.
(iv) All overhead parts shall be fastened or protected in such a manner
that they will not fly off or fall in
event of failure.
(3) Hammers and presses. (i) All hammers shall be positioned or installed in
such a manner that they remain on or
are anchored to foundations sufficient
to support them according to applicable engineering standards.
(ii) All presses shall be installed in
such a manner that they remain where
they are positioned or they are anchored to foundations sufficient to support them according to applicable engineering standards.

TABLE O–11—STRENGTH AND DIMENSIONS FOR WOOD RAM PROPS
Size of timber, inches 1

Square
inches in
cross section

4×4
6×6
8×8
10×10
12×12

Minimum allowable
crushing strength
parallel to grain,
p.s.i.2

16
36
64
100
144

Maximum static load
within short column
range 3

Safety factor

Maximum recommended weight of
forging hammer for
timber used

Maximum allowable
length of
timber,
inches

80,000
180,000
320,000
500,000
720,000

10
10
10
10
10

8,000
18,000
32,000
50,000
72,000

44
66
88
100
132

5,000
5,000
5,000
5,000
5,000

rfrederick on PROD1PC67 with CFR

1 Actual dimension.
2 Adapted from U.S. Department of Agriculture Technical Bulletin 479. Hardwoods recommended are those whose ultimate
crushing strengths in compression parallel to grain are 5,000 p.s.i. (pounds per square inch) or greater.
3 Slenderness ratio formula for short columns is L/d=11, where L=length of timber in inches and d=least dimension in inches;
this ratio should not exceed 11.

(iii) Means shall be provided for disconnecting the power to the machine
and for locking out or rendering cycling controls inoperable.
(iv) The ram shall be blocked when
dies are being changed or other work is
being done on the hammer. Blocks or
wedges shall be made of material the
strength and construction of which
should meet or exceed the specifications and dimensions shown in Table
O–11.
(v) Tongs shall be of sufficient length
to clear the body of the worker in case

of kickback, and shall not have sharp
handle ends.
(vi) Oil swabs, or scale removers, or
other devices to remove scale shall be
provided. These devices shall be long
enough to enable a man to reach the
full length of the die without placing
his hand or arm between the dies.
(vii) Material handling equipment
shall be of adequate strength, size, and
dimension to handle diesetting operations safely.
(viii) A scale guard of substantial
construction shall be provided at the

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rfrederick on PROD1PC67 with CFR

Occupational Safety and Health Admin., Labor
back of every hammer, so arranged as
to stop flying scale.
(ix) A scale guard of substantial construction shall be provided at the back
of every press, so arranged as to stop
flying scale.
(b) Hammers, general—(1) Keys. Die
keys and shims shall be made from a
grade of material that will not unduly
crack or splinter.
(2) Foot operated devices. All foot operated devices (i.e., treadles, pedals, bars,
valves, and switches) shall be substantially and effectively protected from
unintended operation.
(c) Presses. All manually operated
valves and switches shall be clearly
identified and readily accessible.
(d) Power-driven hammers—(1) Safety
cylinder head. Every steam or airhammer shall have a safety cylinder
head to act as a cushion if the rod
should break or pullout of the ram.
(2) Shutoff valve. Steam hammers
shall be provided with a quick closing
emergency valve in the admission pipeline at a convenient location. This
valve shall be closed and locked in the
off position while the hammer is being
adjusted, repaired, or serviced, or when
the dies are being changed.
(3) Cylinder draining. Steam hammers
shall be provided with a means of cylinder draining, such as a self-draining
arrangement or a quick-acting drain
cock.
(4) Pressure pipes. Steam or air piping
shall conform to the specifications of
American National Standard ANSI
B31.1.0–1967, Power Piping with Addenda issued before April 28, 1971,
which is incorporated by reference as
specified in § 1910.6.
(e) Gravity hammers—(1) Air-lift hammers. (i) Air-lift hammers shall have a
safety cylinder head as required in
paragraph (d)(1) of this section.
(ii) Air-lift hammers shall have an
air shutoff valve as required in paragraph (d)(2) of this section.
(iii) Air-lift hammers shall be provided with two drain cocks: one on
main head cylinder, and one on clamp
cylinder.
(iv) Air piping shall conform to the
specifications of the ANSI B31.1.0–1967,
Power Piping with Addenda issued before April 28, 1971, which is incor-

§ 1910.218

porated by reference as specified in
§ 1910.6.
(2) Board drophammers. (i) A suitable
enclosure shall be provided to prevent
damaged or detached boards from falling. The board enclosure shall be securely fastened to the hammer.
(ii) All major assemblies and fittings
which can loosen and fall shall be properly secured in place.
(f) Forging presses—(1) Mechanical
forging presses. When dies are being
changed or maintenance is being performed on the press, the following shall
be accomplished:
(i) The power to the press shall be
locked out.
(ii) The flywheel shall be at rest.
(iii) The ram shall be blocked with a
material the strength of which shall
meet or exceed the specifications or dimensions shown in Table O–11.
(2) Hydraulic forging presses. When
dies are being changed or maintenance
is being performed on the press, the following shall be accomplished:
(i) The hydraulic pumps and power
apparatus shall be locked out.
(ii) The ram shall be blocked with a
material the strength of which shall
meet or exceed the specifications or dimensions shown in Table O–11.
(g) Trimming presses—(1) Hot trimming
presses. The requirements of paragraph
(f)(1) of this section shall also apply to
hot trimming presses.
(2) Cold trimming presses. Cold trimming presses shall be safeguarded in
accordance with § 1910.217(c).
(h) Upsetters—(1) General requirements.
All upsetters shall be installed so that
they remain on their supporting foundations.
(2) Lockouts. Upsetters shall be provided with a means for locking out the
power at its entry point to the machine
and rendering its cycling controls inoperable.
(3) Manually operated controls. All
manually operated valves and switches
shall be clearly identified and readily
accessible.
(4) Tongs. Tongs shall be of sufficient
length to clear the body of the worker
in case of kickback, and shall not have
sharp handle ends.
(5) Changing dies. When dies are being
changed, maintenance performed, or
any work done on the machine, the

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§ 1910.219

29 CFR Ch. XVII (7–1–07 Edition)

power to the upsetter shall be locked
out, and the flywheel shall be at rest.
(i)
Other
forging
equipment—(1)
Boltheading. The provisions of paragraph (h) of this section shall apply to
boltheading.
(2) Rivet making. The provisions of
paragraph (h) of this section shall
apply to rivet making.
(j) Other forge facility equipment—(1)
Billet shears. A positive-type lockout
device for disconnecting the power to
the shear shall be provided.
(2) Saws. Every saw shall be provided
with a guard of not less than oneeighth inch sheet metal positioned to
stop flying sparks.
(3) Conveyors. Conveyor power transmission equipment shall be guarded in
accordance with ANSI B20.1–1957, Safety Code for Conveyors, Cableways, and
Related Equipment, which is incorporated by reference as specified in
§ 1910.6.
(4) Shot blast. The cleaning chamber
shall have doors or guards to protect
operators.
(5) Grinding. Personal protective
equipment shall be used in grinding operations, and equipment shall be used
and maintained in accordance with
ANSI B7.1–1970, Safety Code for the
Use, Care, and Protection of Abrasive
Wheels, which is incorporated by reference as specified in § 1910.6, and with
§ 1910.215.

rfrederick on PROD1PC67 with CFR

[39 FR 23502, June 27, 1974, as amended at 49
FR 5323, Feb. 10, 1984; 51 FR 34561, Sept. 29,
1986; 61 FR 9240, Mar. 7, 1996]

§ 1910.219 Mechanical
power-transmission apparatus.
(a) General requirements. (1) This section covers all types and shapes of
power-transmission belts, except the
following when operating at two hundred and fifty (250) feet per minute or
less: (i) Flat belts one (1) inch or less in
width, (ii) flat belts two (2) inches or
less in width which are free from metal
lacings or fasteners, (iii) round belts
one-half (1⁄2) inch or less in diameter;
and (iv) single strand V-belts, the
width of which is thirteen thirty-seconds (13⁄32) inch or less.
(2) Vertical and inclined belts (paragraphs (e) (3) and (4) of this section) if
not more than two and one-half (21⁄2)
inches wide and running at a speed of

less than one thousand (1,000) feet per
minute, and if free from metal lacings
or fastenings may be guarded with a
nip-point belt and pulley guard.
(3) For the Textile Industry, because
of the presence of excessive deposits of
lint, which constitute a serious fire
hazard, the sides and face sections only
of nip-point belt and pulley guards are
required, provided the guard shall extend at least six (6) inches beyond the
rim of the pulley on the in-running and
off-running sides of the belt and at
least two (2) inches away from the rim
and face of the pulley in all other directions.
(4) This section covers the principal
features with which power transmission safeguards shall comply.
(b) Prime-mover guards—(1) Flywheels.
Flywheels located so that any part is
seven (7) feet or less above floor or
platform shall be guarded in accordance with the requirements of this subparagraph:
(i) With an enclosure of sheet, perforated, or expanded metal, or woven
wire;
(ii) With guard rails placed not less
than fifteen (15) inches nor more than
twenty (20) inches from rim. When
flywheel extends into pit or is within 12
inches of floor, a standard toeboard
shall also be provided;
(iii) When the upper rim of flywheel
protrudes through a working floor, it
shall be entirely enclosed or surrounded by a guardrail and toeboard.
(iv) For flywheels with smooth rims
five (5) feet or less in diameter, where
the preceding methods cannot be applied, the following may be used: A
disk attached to the flywheel in such
manner as to cover the spokes of the
wheel on the exposed side and present a
smooth surface and edge, at the same
time providing means for periodic inspection. An open space, not exceeding
four (4) inches in width, may be left between the outside edge of the disk and
the rim of the wheel if desired, to facilitate turning the wheel over. Where
a disk is used, the keys or other dangerous projections not covered by disk
shall be cut off or covered. This subdivision does not apply to flywheels
with solid web centers.

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