270 Hand and Portable Powered Tools and Equipment
270.01 Scope
270.02 Definitions Applicable to this Section
270.03 General Requirements
270.04 Compressed Air
270.05 Compressed Air Tools
270.06 Air Hammer
270.07 Portable Circular Saws
270.08 Saber, Scroll, and Jig Saws
270.09 Portable Belt Sanding Machines
270.10 Switches and Controls
270.11 Portable Abrasive Wheel Grinders
270.12 Powder Actuated Fastening Systems
270.13 Power Lawnmowers
270.14 Jacks

270. HAND AND PORTABLE POWERED TOOLS AND EQUIPMENT. (7-1-97)

01. Scope: (7-1-97)

a. Hand and portable powered tools and equipment shall conform to all other applicable requirements of this standard, as well as the following provisions. Nothing in this standard shall be construed to prohibit better or otherwise safer conditions than specified herein. (7-1-97)

b. The purpose of this section is to provide reasonable safety for life, limb, and property, by establishing requirements for design, construction, operation, service, and storage of powder actuated fastening tools, fasteners, and power loads. (7-1-97)

02. Definitions: For definitions of other terms used in this section, see sub-section 010 of this standard. (7-1-97)

a. Angle Control is a safety feature designed to prevent a tool from operating when tilted beyond a predetermined angle. (7-1-97)

b. Blade Tip Circle is the path described by the outermost point of the blade as it is rotated about its shaft axis. (7-1-97)

c. Cased Powder Load is a powder load with the propellant contained in a closed case. (7-1-97)

d. Caseless Powder Load is a powder load with the propellant in solid form not requiring containment. (7-1-97)

e. Catcher Assemblies are parts or combinations of parts which provide a means for collecting grass clippings or debris. (7-1-97)

f. Chamber (noun) is the location in the tool into which the powder load is placed and in which it is actuated. (7-1-97)

g. Chamber (verb) is to fit the chamber according to the manufacturer's specifications. (7-1-97)

h. Deadman Control is a control designed so that it will automatically interrupt power to a drive when the operator's actuating force is removed. (7-1-97)

i. Direct-Acting Tool is a tool in which the expanding gas of the powder load acts directly on the fastener to be driven. (7-1-97)

j. Fasteners are any pins (unthreaded heads) or studs (threaded heads) driven by powder actuated tools. (7-1-97)

k. Fixture is a special shield that provides equivalent protection where the standard shield cannot be used. (7-1-97)

l. Guards are a part or an assembly provided for shielding a hazardous area of a machine. (7-1-97)

m. Head is that portion of a fastener that extends above the work surface after being properly driven. (7-1-97)

n. High-Velocity Tool is a tool whose test velocity has been measured ten (10) times while utilizing the combination of: the lightest commercially available fastener designed for the tool; the strongest commercially available powder load which will properly chamber in the tool; and that will produce an average velocity from the ten (10) tests in excess of four-hundred-nighty-two (492) feet per second. (7-1-97)

o. Indirect-Acting Tool is a tool in which the expanding gas of the powder load acts on a captive piston, which in turn drives the fastener. (7-1-97)

p. Jack is an appliance for lifting and lowering or moving horizontally a load by application of a pushing force. NOTE: Jacks may be of the following types: lever and ratchet, screw and hydraulic. (7-1-97)

q. Lowest Blade Position is the lowest blade position under static conditions. (7-1-97)

r. Low Velocity Tool is a tool whose test velocity has been measured ten (10) times while utilizing the highest velocity combination of: the lightest commercially available fastener designed for that specific tool; the strongest commercially available powder load that will properly chamber in the tool; and the piston designed for that tool and appropriate for that fastener; that will produce an average test velocity from the ten (10) tests not in excess of three-hundred-twenty-eight (328) feet per second with no single test having a velocity of over three-hundred-fifty-four (354) feet per second. (7-1-97)

s. Medium-Velocity Tool is a tool whose velocity has been measured ten (10) times while utilizing the highest velocity combination of: the lightest commercially available fastener designed for the tool; the strongest commercially available powder load that will properly chamber in the tool; and the piston designed for that tool and appropriate for that fastener; that will produce an average test velocity from ten (10) tests in excess of three-hundred-twenty-eight (328) feet per second but not in excess of four-hundred-nighty-two (492) feet per second with no single test having a velocity of five-hundred-twenty-five (525) feet per second. (7-1-97)

t. Misfire is a condition in which the powder load fails to ignite after the tool has been operated. (7-1-97)

u. Mounted Wheels usually two (2) inch diameter or smaller, and of various shapes, may be either organic or inorganic bonded abrasive wheels. They are secured to plain or threaded steel mandrels. (7-1-97)

v. Operator Area for discharge interference purposes, that area confined within a circle no smaller than thirty (30) inches in diameter, the center of which is located to the rear of the mower on its longitudinal centerline thirty (30) inches behind the nearest blade tip circle. (7-1-97)

w. Organic Bonded Wheels are wheels which are bonded by means of an organic material such as resin, rubber, shellac, or other similar bonding agent. (7-1-97)

x. Portable Grinding is a grinding operation where the grinding machine is designed to be hand held and may be easily moved from one location to another. (7-1-97)

y. Powder Actuated Fastening System is a method comprising the use of a powder actuated tool, a powder load, and a fastener. (7-1-97)

z. Powder Actuated Tool is a tool that utilizes the expanding gases from a powder load to drive a fastener. (7-1-97)

aa. Powder Load is the energy source used in powder actuated tools. (7-1-97)

bb. Power Reel Mower is a lawn-cutting machine utilizing a power source to rotate one or more helically formed blades about a horizontal axis to provide a shearing action with a stationary cutter bar or bed knife. (7-1-97)

cc. Power Rotary Mower is a lawn-cutting machine utilizing a power source to rotate one or more cutting blades about a vertical axis. (7-1-97)

dd. Qualified Operator is a person who meets the requirements of sub-section 270.12.fff. through sub-section 270.12.hhh. of this section. (7-1-97)

ee. Rating of a jack is the maximum working load for which it is designed to lift safely that load throughout its specified amount of travel. NOTE: To raise the rated load of a jack, the point of application of the load, the applied force, and the length of the lever arm should be those designated by the manufacturer for the particular jack considered. (7-1-97)

ff. Reinforced Wheels as applied to grinding wheels shall define a class of organic wheels which contain strengthening fabric or filament. The term reinforced does not cover wheels using such mechanical additions as steel rings, steel cup backs, or wire or tape winding. (7-1-97)

gg. Riding Mower is a powered, self-propelled lawn cutting vehicle on which the operator rides and controls the machine. (7-1-97)

hh. Safety Guard is a safety guard is an enclosure designed to restrain the pieces of the grinding wheel and furnish all possible protection in the event that the wheel is broken in operation. (7-1-97)

ii. Shield is a device, attached to the muzzle end of a powder actuated tool, which is designed to confine flying particles. (7-1-97)

jj. Spalled area is a damaged and non-uniform concrete or masonry surface. (7-1-97)

kk. Sulky Type Mower is normally a walk-behind mower which has been converted to a riding mower by the addition of a sulky. (7-1-97)

ll. Test Velocity is the measurement of fastener velocity performed in accordance with sub-section 270.12.p. of this section. (7-1-97)

mm. Tuck Pointing is removal, by grinding, of cement, mortar, or other nonmetallic jointing material. (7-1-97)

nn. Tuck Pointing Wheels are usually Type-1, reinforced organic bonded wheels have diameter thickness and hole size dimension. They are subject to the same limitations of use and mounting as Type 1 wheels defined in sub-section 270.12.qq. of this section. Limitation: Wheels used for tuck pointing shall be reinforced, organic bonded. (7-1-97)

oo. Type-II Flaring Cup Wheels are wheels that have double diameter dimensions d. and j., and in addition have thickness, hole size, rim and back thickness dimensions. Grinding is always performed on rim face, W dimension. Type II wheels are subject to all limitations of use and mounting listed for Type-6 straight sided cup wheels definition in i. of this subsection. See Figure 270.02-A. Type- II - Flaring-cup Wheel Side grinding wheel having a wall flared or tapered outward from the back. Wall thickness at the back is normally greater than at the grinding face (W).

FIGURE 270.02-A

pp. Type-6 Cup Wheels have diameter, thickness, hole size, rim thickness, and back thickness dimensions. Grinding is always performed on rim face, W dimension. Limitation: Minimum back thickness, E dimension, should not be less than one-fourth (1/4) T dimension. In addition, when unthreaded hole wheels are specified, the inside flat, K dimension, must be large enough to accommodate a suitable flange. Side grinding wheel having a diameter, thickness and hole with one side straight or flat and the opposite side recessed. This type, however, differs from Type-5 in that the grinding is performed on the wall of the abrasive created by difference between the diameter of the recess and the outside diameter of the wheel. Therefore, the wall dimension "W" takes precedence over the diameter of the wheel D. (7-1-97)

FIGURE 270.02-B

qq. Type-I Straight Wheels have a diameter, thickness, and hole size dimensions and should be used only on the periphery. Type-1 wheels shall be mounted between flanges. Limitation: Hole dimension (H) should not be greater than two-thirds (2/3) of wheel diameter dimension (D) for precision, cylindrical, center less, or surface grinding applications. Maximum hole size for all other application should not exceed one-half wheel diameter. See Figure 270.02-C. (7-1-97)

FIGURE 270.02-C

rr. Walk-Behind Mower is a mower either pushed or self-propelled and normally guided by the operator walking behind the unit. (7-1-97)

03. General Requirements: (7-1-97)

a. Each employer shall be responsible for the safe condition of tools and equipment used by employees, including tools and equipment which may be furnished by employees. (7-1-97)

b. All cracked blades and wheels shall be removed from service. (7-1-03)

c. Portable electric powered tools shall meet the electrical requirements of section 150 of this standard and the National Electrical Code. (7-1-97)

04. Compressed Air: (7-1-97)

a. Compressed air shall not be used for cleaning purposes except where reduced to less than thirty (30) psi and then only with effective chip guarding and personal protective equipment. (7-1-97)

b. Compressed air shall not be used for cleaning personnel, or clothing and equipment while they are being worn. (7-1-97)

c. Air hose and hose connections used for conducting compressed air to equipment shall be designed for the pressure and service to which they are subjected. (7-1-97)

05. Compressed Air Tools: (7-1-97)

a. The operating trigger on portable hand-operated equipment shall be so located as to minimize the possibility of its accidental operation and shall be arranged to close the air inlet valve automatically when the pressure of the operator's hand is removed. (7-1-97)

b. When momentarily out of use the gun should be laid in such position that the tool cannot fly out if the pressure is accidentally released. When not in use, all tools should be removed from the gun. (7-1-97)

c. In disconnecting a compressed air tool from the air line, care shall be exercised first to shut off the pressure and then to operate the tool to exhaust the pressure remaining in the hose. (7-1-97)

d. Compressed air hose or guns shall not be pointed at or brought into contact with the body of any person. (7-1-97)

e. In the use of compressed air tools, care should be used to prevent the tool from being shot from the gun. (7-1-97)

f. A tool retainer shall be installed on each piece of equipment which, without such a retainer, may eject the tool. (7-1-97)

06. Air Hammer: (7-1-97)

a. Before laying down an air hammer, remove tool from hammer unless it is held in place by safety catch. (7-1-97)

07. Portable Circular Saws: (7-1-97)

a. All portable power-driven circular saws having a blade diameter greater than two (2) inches shall be equipped with guards above and below the base plate or shoe. The upper guard shall cover the saw to the depth of the teeth, except for the minimum arc required to permit the base to be tilted for bevel cuts. The lower guard shall cover the saw to the depth of the teeth, except for the minimum arc required to allow proper retraction and contact with the work, the lower guard shall automatically and instantly return to covering position. This section does not apply to circular saws used in the meat industry for meat cutting purposes. (7-1-97)

08. Saber, Scroll, and Jig Saws: (7-1-97)

a. Saber, scroll, and jig saws, with nonstandard blade holders, may use blades with shanks which are nonuniform in width, provided the narrowest portion of the blade shank is an integral part in the mounting of the blade. (7-1-97)

b. Blade shank width shall be measured at the narrowest portion of the blade shank when saber, scroll, and jig saws have non-standard blade holders. (7-1-97)

09. Portable Belt Sanding Machines: (7-1-97)

a. Belt sanding machines shall be provided with guards at each nip point where the sanding belt runs onto a pulley. These guards shall effectively prevent the hands or fingers of the operator from coming in contact with the nip points. The unused run of the sanding belt shall be guarded against accidental contact. (7-1-97)

10. Switches and Controls: (7-1-97)

a. All hand held powered circular saws having a blade diameter greater than 2-inches, electric, hydraulic, or pneumatic chain saws, and percussion tools without positive accessory holding means shall be equipped with a constant pressure switch or control that will shut off the power when the pressure is released. All hand held gasoline powered chain saws shall be equipped with a constant pressure throttle control that will shut off the power to the saw chain when the pressure is released. (7-1-97)

b. All hand-held powered drills, tappers, fastener drivers, horizontal, vertical, and angle grinders with wheels greater than two (2) inches in diameter, disc sanders with discs greater than two (2) inches in diameter, belt sanders, reciprocating saws, saber, scroll, and jig saws with blade shanks greater than a nominal one-fourth (1/4) inch, and other similarly operating powered tools shall be equipped with a constant pressure switch or control and may have a lock-on control provided that turnoff can be accomplished by a single motion of the same finger or fingers that turn it on. (7-1-97)

c. All other hand-held powered tools such as, but not limited to, platen sanders, grinders with wheels two (2) inches in diameter or less, disc sanders with discs two (2) inches in diameter or less, routers, planers, laminate trimmers, nibblers, shears, saber, scroll, and jig saws with blade shanks a nominal one-fourth (1/4) inch wide or less, may be equipped with either a positive on-off control, or other controls as described in sub-section 270.08.a. and b. of this section. (7-1-97)

d. The operating control on hand-held power tools shall be so located as to minimize the possibility of its accidental operation, if such accidental operation would constitute a hazard to employees. (7-1-97)

e. This subsection does not apply to concrete vibrators, concrete breakers, powered tampers, jack hammers, rock drills, garden appliances, household and kitchen appliances, personal car appliances, medical or dental equipment, or to fixed machinery. (7-1-97)

11. Portable Abrasive Wheel Grinders: (7-1-97)

a. All abrasive wheels shall be used only on machines provided with safety guards as defined in this subsection. Exceptions: This requirement shall not apply to the following classes of wheels and conditions: wheels used for internal work while within the work being ground; mounted wheels used in portable grinders two (2) inches and smaller in diameter; and types 16, 17, 18, 18R, and 19 cones and plugs and threaded hole pot balls as illustrated and described in 1.4.11 of ANSI B7.1-1970 Safety Code for the Use, Care and Protection of Abrasive Wheels, where the work offers protection. (7-1-97)

b. The safety guard shall cover the spindle end, nut, and flange projections. The safety guard shall be mounted so as to maintain proper alignment with the wheel, and the strength of the fastenings shall exceed the strength of the guard. Exceptions: Safety guards on all operations where the work provides a suitable measure of protection to the operator, may be so constructed that the spindle end, nut, and outer flange are exposed; the spindle end, nut and outer flange may be exposed on portable machines designed for, and used with, type 6, 11, 27, and 28 abrasive wheels, cutting off wheels, and tuck pointing wheels; and the spindle end, nut, and outer flange may be exposed on machines designed as portable saws. (7-1-97)

c. Cup wheels (type 6 and 11) shall be guarded by safety guards as specified in this subsection. (7-1-97)

d. Special revolving cup guards which mount behind the wheel and turn with it. They shall be made of steel or other material with adequate strength and shall enclose the wheel sides upward from the back for one-third of the wheel thickness. The mounting features shall conform with all regulations. (See sub-section 270.11.g. through sub-section 270.11.k. of this section). It is necessary to maintain clearance between the wheel side and the guard. The clearance shall not exceed one-sixteenth (1/16) inch; or, some other form of guard that will insure as good protection as that which would be provided by the guards specified in sub-section 270.11.b. of this section. (7-1-97)

e. Safety guards used on machines known as right angle head or vertical portable grinders shall have a maximum exposure angle of one-hundred-eighty (180) degrees, and the guard shall be located so as to be between the operator and the wheel during use. Adjustment of guard shall be such that pieces of an accidentally broken wheel will be deflected away from the operator. (See Figure 270.11-A). (7-1-97)

FIGURE 270.11-A

f. The maximum angular exposure of the grinding wheel periphery and sides for safety guards used on other portable grinding machines shall not exceed one-hundred-eighty (180) degrees and the top half of the wheel shall be enclosed at all times. (See Figures 270.11-B). (7-1-97)

FIGURE 270.11-B

g. Immediately before mounting, all wheels shall be closely inspected and sounded by the user (ring test) to make sure they have not been damaged in transit, storage, or otherwise. The spindle speed of the machine shall be checked before mounting of the wheel to be certain that it does not exceed the maximum operating speed marked on the wheel. Wheels should be tapped gently; if they sound cracked (dead), they shall not be used. NOTE: Wheels shall be tapped gently with a light nonmetallic implement, such as the handle of a screwdriver for light wheels, or a wooden mallet for heavier wheels. This is known as the Ring Test. (7-1-97)

h. Grinding wheels shall fit freely on the spindle and remain free under all grinding conditions. The machine spindle shall be made to nominal (standard) size plus zero (0) minus zero-point-zero-zero-two (0.002) inch, and the wheel hole shall be made suitably oversize to assure safety clearance under the conditions of operating heat and pressure. NOTE: A controlled clearance between the wheel hole and the machine spindle (or wheel sleeves or adapters) is essential to avoid excessive pressure from mounting and spindle expansion. (7-1-97)

i. All contact surfaces of wheels, blotters, and flanges shall be flat and free of foreign matter. (7-1-97)

j. When a bushing is used in the wheel hole, it shall not exceed the width of the wheel and shall not contract the flanges. (7-1-97)

k. For requirements for the use of flanges and blotters see sub-section 250.20.x. through sub-section 250.20.z. of this standard. NOTE: Excluded machinery. Natural sandstone wheels and metal, wooden, cloth, or paper discs, having a layer of abrasive on the surface are not covered by this subsection. (7-1-97)

12. Powder Actuated Fastening Systems: (7-1-97)

a. This Section provides safety requirements for a powder actuated fastening tool or machine which propels a stud, pin, fastener, or other object for the purpose of affixing it by penetration to another object. (7-1-97)

b. This subsection does not apply to devices designed for attaching objects to soft construction materials, such as wood, plaster, tar, dry wallboard, and the like, or to stud welding equipment. (7-1-97)

c. Powder actuated tools can be divided into two types: direct acting and indirect acting; and three classes: low velocity, medium velocity, and high velocity. (7-1-97)

d. The tool shall be designed to prevent inadvertent actuation. (7-1-97)

e. The tool shall be designed to prevent actuation when dropped in any attitude from a height of ten (10) feet onto a smooth, hard surface such as concrete or steel, if such actuation can propel a fastener or any part thereof in free flight. (7-1-97)

f. Actuation of the tool shall be dependent upon at least two (2) separate and distinct operations by the operator, with at least one (1) operation being separate from the operation of holding the tool against the work surface. (7-1-97)

g. The tool shall be designed not to be operable other than against a work surface with a force on the work surface equal to five (5) pounds greater than the weight of the tool or a minimum impact energy of three (3) foot-pounds. (7-1-97)

h. All tools shall be designed so that compatible protective shields or fixtures, designed, built, and supplied by the manufacturer of the tool can be used (see sub-section 270.12.q. of this section). (7-1-97)

i. The tool shall be designed so that a determinable means of varying the power levels is available for selecting a power level adequate to perform the desired work (See sub-section 270.12.x. of this section). (7-1-97)

j. The tool shall be designed so that all principal functional parts can be checked for foreign matter that may affect operation. (7-1-97)

k. The tool shall be designed so that all parts will be of adequate strength to resist maximum stresses imposed on actuation when the tool is used in accordance with the manufacturer's instructions and is powered by any commercially available powder load which will properly chamber in the tool. (7-1-97)

l. Each tool shall bear a legible permanent model designation, which shall serve as a means of identification. Each tool shall also bear a legible, permanent manufacturer's unique serial number. (7-1-97)

m. A lockable container shall be provided for each tool. The works POWDER ACTUATED TOOL shall appear in plain sight on the outside of the container. The following notice shall be attached on the inside cover of the container: WARNING, POWDER ACTUATED TOOL TO BE USED ONLY BY A QUALIFIED OPERATOR AND KEPT UNDER LOCK AND KEY WHEN NOT IN USE. (7-1-97)

n. Each tool shall bear a durable warning label with the following statement, or the equivalent: WARNING, FOR USE ONLY BY QUALIFIED OPERATORS ACCORDING TO MANUFACTURER'S INSTRUCTION MANUAL. (7-1-97)

o. Each tool shall be supplied with the following: operator's instruction and service manual; power load chart; tool inspection record; service tools and accessories. (7-1-97)

p. In determining tool test velocities the velocity of the fastener shall be measured in free flight at a distance of six and one-half (6 1/2) feet from the muzzle end of the tool, using accepted ballistic test methods. (7-1-97)

q. Low-velocity tools shall be supplied with a shield. Medium-velocity tools shall have a shield at least two and one-half (2 1/2) inches in diameter mounted perpendicular to, and concentric with the muzzle end, when it is indexed to the center position. High-velocity tools shall have a shield at least three and one-half (3 1/2) inches in diameter mounted perpendicular to, and concentric with, the muzzle end, when it is indexed to the center position. A special shield or fixture may be used when it provides equivalent protection. (7-1-97)

r. The powder actuated tools shall be designed so that it cannot be actuated unless it is equipped with a shield or fixture. (7-1-97)

s. The medium-velocity tools shall be designed with angle control so that it will not actuate when equipped with the standard shield indexed to the center position if the bearing surface of the shield is tilted more than twelve (12) degrees from a flat surface. (7-1-97)

t. The high-velocity tool shall be designed with angle control so that it will not actuate when equipped with the standard shield indexed to the center position, if the bearing surface of the shield is tilted more than eight (8) degrees from a flat surface. (7-1-97)

u. Cased powder loads shall be coded to identify powder load levels by case color and powder load color as specified in Table 270.12-A. Caseless powder loads shall be coded to identify powder load levels by powder load color as specified in Table 270.12-A and by configuration. (7-1-97)

271. -- 279. (RESERVED)