Central Pneumatic 92921 User manual

1/2” AIR COMPOSITE
IMPACT WRENCH
ASSEMBLY AND OPERATING
INSTRUCTIONS
3491 Mission Oaks Blvd., Camarillo, CA 93011
Visit our Web site at http://www.harborfreight.com
Model 92921
Copyright©2005 by Harbor Freight Tools®. All rights reserved. No portion of this manual or any
artwork contained herein may be reproduced in any shape or form without the express written
consent of Harbor Freight Tools.
For technical questions and replacement parts, please call 1-800-444-3353.
Manual Revised 11h
TO PREVENT SERIOUS INJURY,
READ AND UNDERSTAND ALL WARNINGS
AND INSTRUCTIONS BEFORE USE.

Page 2SKU 92921 For technical questions, please call 1-800-444-3353
Specications
Save This Manual
You will need the manual for the safety warnings and precautions, assembly instructions,
operating and maintenance procedures, parts list and diagram. Keep your invoice with this
manual. Write the invoice number on the inside of the front cover. Keep the manual and
invoice in a safe and dry place for future reference.
Safety Warnings and Precautions
WARNING: When using tool, basic safety precautions should always be followed to
reduce the risk of personal injury and damage to equipment.
Read all instructions before using this tool!
1. Keep work area clean. Cluttered areas invite injuries.
2. Observe work area conditions. Do not use machines or power tools in damp or wet
locations. Don’t expose to rain. Keep work area well lighted. Do not use electrically
powered compressors in the presence of ammable gases or liquids.
3. Keep children away. Children must never be allowed in the work area. Do not let
them handle machines, tools, extension cords, or air hoses.
4. Store idle equipment. When not in use, tools must be stored in a dry location to
inhibit rust. Always lock up tools and keep out of reach of children.
5. Use the right tool for the job. Do not attempt to force a small tool or attachment
to do the work of a larger industrial tool. There are certain applications for which this
tool was designed. It will do the job better and more safely at the rate for which it was
intended. Do not modify this tool and do not use this tool for a purpose for which it
was not intended.
6. Dress properly. Do not wear loose clothing or jewelry as they can be caught in
moving parts. Protective, electrically non-conductive clothes and non-skid footwear
are recommended when working. Wear restrictive hair covering to contain long hair.
7. Use eye and ear protection. Always wear ANSI approved impact safety
goggles and hearing protection. Wear a full face shield if you are producing
metal lings or wood chips. Wear an ANSI approved dust mask or respirator
when working around metal, wood, and chemical dusts and mists.
Maximum Torque 260 Ft. Lbs.
Drive Size 1/2”
Impact Mechanism Rocking Dog
Air Inlet 1/4” - 18 NPT
Recommended Air Pressure 90 PSI
No Load RPM 7,000
Air Consumption 4.5 CFM

Page 3SKU 92921 For technical questions, please call 1-800-444-3353
8. Do not overreach. Keep proper footing and balance at all times. Do not reach over
or across running machines or air hoses.
9. Maintain tools with care. Keep tools clean for better and safer performance. Follow
instructions for lubricating and changing accessories. Inspect tool cords and air hoses
periodically and, if damaged, have them repaired by an authorized technician. The
handles must be kept clean, dry, and free from oil and grease at all times.
10. Disconnect air supply. Disconnect air hose when not in use.
11. Remove adjusting keys and wrenches. Check that keys and adjusting wrenches
are removed from the tool or machine work surface before plugging it in.
12. Avoid unintentional starting. Be sure the trigger is released when not in use and
before plugging in. Do not carry any tool with your nger on the trigger, whether it is
plugged in or not.
13. Stay alert. Watch what you are doing, use common sense. Do not operate any tool
when you are tired.
14. Check for damaged parts. Before using any tool, any part that appears damaged
should be carefully checked to determine that it will operate properly and perform its
intended function. Check for alignment and binding of moving parts; any broken parts
or mounting xtures; and any other condition that may affect proper operation. Any
part that is damaged should be properly repaired or replaced by a qualied technician.
Do not use the tool if any switch does not turn On and Off properly.
15. Guard against electric shock. Prevent body contact with grounded surfaces such as
pipes, radiators, ranges, and refrigerator enclosures.
16. Replacement parts and accessories. When servicing, use only identical
replacement parts. Use of any other parts will void the warranty. Only use accessories
intended for use with this tool. Approved accessories are available from Harbor
Freight Tools.
17. Do not operate tool if under the inuence of alcohol or drugs. Read warning
labels if taking prescription medicine to determine if your judgement or reexes are
impaired while taking drugs. If there is any doubt, do not operate the Wrench.
18. Use proper size and type extension cord. If an extension cord is required, it
must be of the proper size and type to supply the correct current to the compressor
without heating up. Otherwise, the extension cord could melt and catch re, or cause
electrical damage to the compressor. Check your air compressor’s manual for the
appropriate size cord.
19. Maintenance. For your safety, maintenance should be performed regularly by a
qualied technician.
20. Compressed air only. Never use combustible gas as a power source.
21. This Impact Wrench should only be used with impact sockets and extensions.
Using any other accessories can cause the accessories to break, causing permanent
damage to the unit and severe injury to the operator.

Page 4SKU 92921 For technical questions, please call 1-800-444-3353
Unpacking
When unpacking, check to make sure the parts listed on page 8 are included. If any
parts are missing or broken, please call Harbor Freight Tools at the number on the cover of
this manual as soon as possible.
1. You will need to prepare a 3/8” air connector (not included) to connect to the Air Inlet
(40) on the Impact Wrench. First, wrap the 3/8” air connector with pipe thread seal tape
before threading it into the Air Inlet (40). Connect the 3/8” ID Air Source Hose to a quick
connect coupler (not included), and then to the Impact Wrench.
Note: If you are not using an automatic oiler system, before operation, add a few drops
of Pneumatic Tool Oil to the airline connection. Add a few drops more after each hour
of continual use.
2. Set the air pressure on the regulator to 90 PSI. Do not exceed the recommended
air pressure of 90 PSI.
3. Check the air connection for leaks. Disconnect from the air source.
Operation
For best service you should incorporate an oiler, regulator, and inline lter, as shown in the
diagram above. Hoses, couplers, oilers, regulators, and lters are all available at Harbor
Freight Tools.
Impact
Wrench
Note: Performance of the compressor (if powered by line voltage) may vary depending
on variations in local line voltage. Extension cord usage may also affect tool
performance.
Warning: The warnings, cautions, and instructions discussed in this instruction manual
cannot cover all possible conditions and situations that may occur. It must be un-
derstood by the operator that common sense and caution are factors which cannot be
built into this product, but must be supplied by the operator.

Page 5SKU 92921 For technical questions, please call 1-800-444-3353
Operation (continued)
Note: Turn off your air compressor and disconnect the air hose when you are changing
sockets. After you attach the socket, attach the air hose and turn the air compressor
on.
4. Select the appropriate size 1/2” drive socket for your needs. Note: Use only impact
type sockets.
5. Push and snap the socket (not included) onto the Anvil (23).
6. To operate the Regulator Knob (17) and Forward / Reverse direction:
For Forward (clockwise) direction, set knob to the right. Note: There are
3 torque setting stops for Forward.
For Reverse (counterclockwise) direction, set knob to the left. Note:
There is 1 torque setting stop for Reverse.
7. Tighten the nut as tight as you can by hand.
8. Place the socket (not included) over the nut you wish to tighten.
9. Grip the Impact Wrench rmly with two hands and gently squeeze the Trigger (30).
Note: If the Impact Wrench cannot tighten the nut to your satisfaction, do not raise the air
pressure on the compressor over 90 PSI. Pressures above 90 PSI will strip the work-
piece and damage the tool, potentially causing the tool to fail, causing serious injury.
Use other appropriate methods and tools to tighten the nut.
10. When the nut is tightened, release the Trigger (30). Turn off the air compressor and
disconnect the hose.
11. If available, check the recommended torque specication for the nut. Use a torque
wrench to tighten the nut to the proper setting after using the Impact Wrench.
Loosening
Note: Set the Regulator Knob (17) to the left so that the anvil turns counterclockwise (reverse).
12. Place the socket (not included) over the nut you wish to loosen.
13. Grip the Impact Wrench rmly with two hands and gently squeeze the Trigger (30).
Note: If the Impact Wrench cannot loosen the nut, do not raise the air pressure on the
compressor over 90 PSI. Do not attempt to loosen the nut with the Impact Wrench.
Use other appropriate methods and tools to loosen the nut.
14. When the nut is loosened, release the Trigger (30). Turn off the air compressor and
disconnect the hose.
15. If needed, remove the nut from the socket.
Refer to FIGURE 1 on page 6, and the Assembly Drawing on page 8.
Warning!! This Impact Wrench supplies powerful torque and is designed to be operated with
two hands. Failure to operate the Impact Wrench with two hands may result in serious injury.

Page 6SKU 92921 For technical questions, please call 1-800-444-3353
90 Day Warranty
Harbor Freight Tools Co. makes every effort to assure that
its products meet high quality and durability standards,
and warrants to the original purchaser that this product
is free from defects in materials and workmanship for
the period of 90 days from the date of purchase. This
warranty does not apply to damage due directly or
indirectly, to misuse, abuse, negligence or accidents,
repairs or alterations outside our facilities, criminal activity,
improper installation, normal wear and tear, or to lack of
maintenance. We shall in no event be liable for death,
injuries to persons or property, or for incidental, contingent,
special or consequential damages arising from the use
of our product. Some states do not allow the exclusion or
limitation of incidental or consequential damages, so the
above limitation of exclusion may not apply to you. THIS
WARRANTY IS EXPRESSLY IN LIEU OF ALL OTHER
WARRANTIES, EXPRESS OR IMPLIED, INCLUDING THE
WARRANTIES OF MERCHANTABILITY AND FITNESS.
To take advantage of this warranty, the product or part
must be returned to us with transportation charges prepaid.
Proof of purchase date and an explanation of the complaint
must accompany the merchandise. If our inspection veries
the defect, we will either repair or replace the product at our
election or we may elect to refund the purchase price if we
cannot readily and quickly provide you with a replacement.
We will return repaired products at our expense, but if we
determine there is no defect, or that the defect resulted
from causes not within the scope of our warranty, then you
must bear the cost of returning the product.
This warranty gives you specic legal rights and you may
also have other rights which vary from state to state.
1. Make sure your Impact Wrench is disconnected from the air hose before attempting
any maintenance.
2. Wipe the Impact Wrench down with a lint free cloth after each use.
3. Make sure the Anvil (23) is clear of dirt or debris. If possible, spray it with compressed
air before each use.
4. Annually, or more often if used on a daily basis, inject oil into the oil port located on the
right side of the Housing (28).
5. If you do not use an inline oiler/lter system, lubricate the tool daily by holding it so that
the Air Inlet (40) is facing up. Squeeze the Trigger (30), and place one or two drops of
oil into the Air Inlet (40). Squeezing the Trigger (30) allows the oil to circulate in the
motor.
Maintenance

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NOTE: Some parts are listed and shown for illustration purposes only and are not available
individually as replacement parts.
PLEASE READ THE FOLLOWING CAREFULLY
THE MANUFACTURER AND/OR DISTRIBUTOR HAS PROVIDED THE PARTS DIAGRAM
IN THIS MANUAL AS A REFERENCE TOOL ONLY. NEITHER THE MANUFACTURER NOR
DISTRIBUTOR MAKES ANY REPRESENTATION OR WARRANTY OF ANY KIND TO THE
BUYER THAT HE OR SHE IS QUALIFIED TO MAKE ANY REPAIRS TO THE PRODUCT OR
THAT HE OR SHE IS QUALIFIED TO REPLACE ANY PARTS OF THE PRODUCT. IN FACT,
THE MANUFACTURER AND/OR DISTRIBUTOR EXPRESSLY STATES THAT ALL REPAIRS
AND PARTS REPLACEMENTS SHOULD BE UNDERTAKEN BY CERTIFIED AND LICENSED
TECHNICIANS AND NOT BY THE BUYER. THE BUYER ASSUMES ALL RISK AND LIABILITY
ARISING OUT OF HIS OR HER REPAIRS TO THE ORIGINAL PRODUCT OR REPLACEMENT
PARTS THERETO, OR ARISING OUT OF HIS OR HER INSTALLATION OF REPLACEMENT
PARTS THERETO.
Parts List

Page 8SKU 92921 For technical questions, please call 1-800-444-3353
Assembly Drawing