Rockwood 31900 User manual

3/8"BUTTERFLY
IMPACT AIR WRENCH
INSTRUCTIONS
Item #31900

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The ROCKWOOD 3/8” “BUTTERFLY” IMPACT AIR WRENCH features a large-capacity five-vane, ball
bearing motor with a twin-headed hammer dog. Fully reversible with an infinitely throttled “Butterfly”
type paddle control.
CONTENTS
(1) 3/8” Butterfly, Inline Impact Wrench
(1) 1/4” MNPT, Male Quick Disconnect
Inlet Fitting
SPECIFICATIONS
Square Drive: 3/8”
RPM: 10,000 free speed
Maximum Torque: 75 ft-lbs [102 N.m]
Air Consumption: 3 cfm [85 L/min] @ 90 PSI
Inlet thread size: 1/4” FNPT
Reversible, variable speed, 5 vane, ball bearing air motor
360° Swivel air inlet with integral torque limiting control knob
DANGER indicates a hazardous situation which, if not avoided, will result in death or serious injury.
WARNING indicates a hazardous situation which, if not avoided, could result in death or serious injury.
CAUTION used with the safety alert symbol, indicates a hazardous situation which, if not avoided,
could result in minor or moderate injury.
NOTICE is used to address practices not related to personal injury.
SAFETY INFORMATION
The following explanations are displayed in this manual, on the labeling, and on all other information
provided with this product:

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READ INSTRUCTIONS
• Thoroughly read and understand these product instructions before using
this tool. Failure to follow all warnings can result in tool damage or serious
physical injury.
• Keep these product instructions for future reference.
EYE INJURY HAZARD!
• Tool can eject metal particles, dirt and debris at high velocity.
Always wear ANSI approved eye protection when operating this tool
HEARING DAMAGE HAZARD!
• This Eastwood Pneumatic Tool emits high sound levels while operating.
Use ANSI approved ear protection when operating.
BURSTING HAZARD!
• Do not exceed 90 psi (6.2 bar) of tool inlet pressure. Permanent tool
damage and/or explosion could occur and cause personal injury.
INJURY HAZARD!
• The tool can suddenly kick back or twist causing severe hand or
wrist injury.
• Always make sure the workpiece is securely clamped or anchored to
avoid sudden movements which could result in injury.
• Frequently inspect impact tool and socket (not Included) condition. If cracks
develop, discontinue use immediately and replace damaged socket.
• Always disconnect tool from air supply when changing sockets and
accessories to prevent accidental tool starting and potential injury.
VIBRATION INJURY HAZARD!
• This tool will vibrate during use! Repeated exposure to vibration may
cause physical injury.

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SET-UP
• Using a good quality Teflon sealing tape (Not Included), thread the 1/4” MNPT, Male quick
disconnect inlet fitting into the air inlet.
CONNECTION
• Be sure that the air supply to the tool is clean and dry. Moisture in the supply line will quickly
damage the motor and valves.
• A minimum 3/8” I.D. air line should be used for optimal performance.
OPERATION
• With air supply disconnected, snap
selected socket or accessory over the
retaining ring nested in the square drive.
• Connect air supply.
- To loosen fasteners:
Depress left side of the “butterfly”
paddle on the back of the body
downward toward the “R”.
To tighten fasteners:
Depress the right side of the
“butterfly” toward the “F” (FIG 1).
- Speed is regulated by pressure
applied to the “butterfly” while speed
and torque are limited by rotating the
control knob located in the air inlet
swivel. 0 is lowest, 8 is highest
(FIG 2).
INJURY HAZARD!
To avoid injury, always disconnect air supply to Wrench when attaching or
removing sockets or accessories.
INJURY HAZARD!
To avoid injury, only use sockets and accessories rated for “Impact” use.
Push to
Loosen
FIG. 1
FIG. 2
Push to
Tighten
Increase
Decrease
✓
✓

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MAINTENANCE
• Add several drops of air tool oil before each use by dropping directly into the air inlet.
• If tool is to be unused for an extended period, add 10 drops of air tool oil directly to the air inlet,
rotate the tool motor by hand several times to distribute the oil throughout the motor then store
the tool, handle up.

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NOTES

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Tool doesn’t
respond to
trigger
depression
Insufficient
volume of air
(CFM) to
operate tool
Verify sufficient air supply to tool.
(3 CFM @ 90 PSI minimum requirement).
Moisture or
other contami-
nation in air
supply
Check for moisture in air line and tool air inlet.
Tool perfor-
mance is slow
or sluggish
Insufficient
volume of air
(CFM) to
operate tool
Verify sufficient air supply to tool.
(3 CFM @ 90 PSI minimum requirement).
Moisture or
other contami-
nation in air
supply
Check for moisture in air line and tool air inlet.
Air Motor
is lacking
lubrication
Stop use immediately and add air tool oil directly
to air inlet.
Tool is exces-
sively noisy/
emits high
pitched sound
Air Motor
is lacking
lubrication
Stop use immediately and add air tool oil directly
to air inlet.
Tool vibrates
excessively
during use
Out of balance
condition from
damaged
socket or
accessory
Stop use immediately, check for damage and
replace socket or accessory.
TROUBLESHOOTING

© Copyright 2017 Easthill Group, Inc. 8/17 Instruction item #31900Q Rev 1
If you have any questions about the use of this product, please contact
The Eastwood Technical Assistance Service Department: 800.343.9353 >> email: [e-mail]
PDF version of this manual is available online >> eastwood.com/31900manual
The Eastwood Company 263 Shoemaker Road, Pottstown, PA 19464, USA
US and Canada: 800.343.9353 Outside US: 610.718.8335
Fax: [phone] eastwood.com
ADDITIONAL ITEMS
#70491 Eastwood Industrial Air Hose, 3/8” x 25’
#70492 Eastwood Industrial Air Hose, 3/8” x 50’