NPK GH Series User manual

HYDRAULIC HAMMER
OPERATORS MANUAL
GH SERIES HAMMERS
GH3-2
“Use Genuine NPK Parts”
© Copyright 2013 NPK Construction Equipment, Inc. www.npkce.com H050-9650A GH3-2 Hyd Ham
Operators Manual 6-13
7550 Independence Drive
Walton Hills, OH 44146-5541
Phone [phone]
Toll-free [phone]
Fax [phone]

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CONTENTS
SAFETY..........................................................................................................................2
INTRODUCTION.............................................................................................................4
CARRIER MACHINE COMPATIBILITY ..........................................................................5
HAMMER SPECIFICATIONS .........................................................................................6
HAMMER SERIAL NUMBER LOCATION.......................................................................7
HYDRAULIC INSTALLATION.........................................................................................8
PREVENTION OF CONTAMINATION........................................................................9
HYDRAULIC QUICK DISCONNECTS......................................................................10
MOUNTING INSTALLATION........................................................................................ 12
SWITCH HAMMER TO ANTI-BLANK FIRE..................................................................13
LUBRICATION.............................................................................................................. 14
GREASING PROCEDURE.......................................................................................14
CORRECT GREASE AND GREASE INTERVALS................................................... 15
NPK HAMMER GREASE.......................................................................................17
LUBRICANT TERMS AND DEFINITIONS................................................................ 18
START-UP OPERATION.............................................................................................. 20
HAMMERS THAT ARE NEW, REBUILT, OR HAVE BEEN INACTIVE ....................20
BEFORE STARTING THE HAMMER....................................................................... 21
DAILY START-UP PROCEDURE............................................................................. 21
OPERATION.................................................................................................................22
OPERATING TECHNIQUES & PRECAUTIONS ...................................................... 23
IMPACT ENERGY TRANSMISSION THROUGH TOOLS............................................ 28
IMPACT STRESS WAVES AT THE END OF THE TOOL........................................29
ROUTINE INSPECTION AND MAINTENANCE............................................................ 30
WEEKLY INSPECTION ................................................................................................31
TYPES AND APPLICATIONS OF TOOL...................................................................... 32
STANDARD TOOLS................................................................................................. 32
ACCESSORY TOOLS .............................................................................................. 32
TOOL IDENTIFICATION............................................................................................... 33
TOOLS..........................................................................................................................34
STANDARD LENGTH FOR NPK TOOLS................................................................. 34
CHANGING THE TOOL............................................................................................35
MAXIMUM TOOL TO TOOL BUSHING CLEARANCE.............................................37
CHISEL TOOL RE-SHARPENING ...........................................................................39
TOOL RETAINING PIN INSPECTION...................................................................... 40
TOOL INSPECTION.................................................................................................41
TOOL BREAKAGE........................................................................................................44
TORQUE VALUES FOR HAMMER FASTENERS........................................................ 52
GAS CHARGE .............................................................................................................. 53
NITROGEN GAS PRESSURE..................................................................................53
GAS CHARGING KIT ............................................................................................... 54
CHECKING THE GAS PRESSURE..........................................................................55
CHARGING THE HAMMER...................................................................................... 57
DISCHARGING THE GAS PRESSURE ................................................................... 58
WARRANTY REGISTRATION FOR NEW UNITS ........................................................ 59
STORAGE OF HYDRAULIC HAMMER........................................................................ 60
WARRANTY STATEMENTS.........................................................................................61
NOTES AND RECORDS ..............................................................................................65

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SAFETY
Safety notices in NPK Instruction Manuals follow ISO and ANSI standards for
safety warnings:
DANGER (red) notices indicate an imminently hazardous situation
which, if not avoided, will result in death or serious injury.
WARNING (orange) notices indicate a potentially hazardous situation
which, if not avoided, could result in death or serious injury.
CAUTION (yellow) notices indicate a potentially hazardous situation,
which, if not avoided, may result in minor or moderate injury.
ATTENTION (blue) notices in NPK Instruction Manuals are an NPK
standard to alert the reader to situations which, if not avoided, could
result in equipment damage.
WARNING and BASIC OPERATING INSTRUCTIONS decals are included with each
NPK hammer and installation kit. Decals must be installed in the cab, visible to the
operator while operating the hammer.
STAY CLEAR, PRESSURE VESSEL, GAS PRESSURE and TOOL SHARPENING
decals are installed on all NPK hammer models. Keep them clean and visible. NPK will
provide decals free of charge as needed.
1. Operator and Service personnel must read and understand the NPK INSTRUCTION
MANUAL to prevent serious or fatal injury.
2. FLYING DEBRIS CAN CAUSE SERIOUS OR FATAL INJURY.
Keep personnel and bystanders clear of hammer while in operation.
Do not operate HAMMER without an impact resistant guard between HAMMER
and operator. NPK recommends LEXANor equivalent material, or steel mesh.
Some carrier manufacturers offer demolition guards for their machine. Check
with the carrier manufacturer for availability. If not
available, please call NPK.
3. Do not hardface or sharpen the tool point with a cutting
torch. Excessive heat from torching or welding can
cause embrittlement, breakage, and flying pieces.
Resharpen by milling or grinding only, using sufficient
coolant.

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SAFETY
4. Fully extend the tool while charging the HAMMER with nitrogen gas. Be sure that
the retaining pin is installed. STAY CLEAR OF TOOL POINT WHILE CHARGING.
5. Do not disassemble a HAMMER before discharging the hammer gas pre-charge.
6. USE NITROGEN GAS ONLY! Store and handle nitrogen tanks per OSHA
regulations.
7. Avoid high pressure fluids. Escaping fluid under pressure can penetrate the skin
causing serious injury. Relieve pressure before disconnecting hydraulic or other
lines.
8. Operate HAMMER from operator’s seat only.
9. Match HAMMER size to carrier according to NPK recommendations. The carrier
must be stable during hammer operation and during transport.
See CARRIER MACHINE COMPATIBILITY section of the NPK instruction manual.
10. Do not make any alterations to the TOOL without authorization from NPK
Engineering.
11. Use proper lifting equipment and tools when handling or servicing the HAMMER.
12. Wear ear protection and safety glasses when operating the hammer. Consult
OSHA/MSHA regulations when applicable.
13. Beware of flying metal pieces when driving Boom Pins.
14. If modifications are to be made, do not alter the HAMMER without authorization
from NPK Engineering!
15. Use only genuine NPK replacement parts. NPK specifically disclaims any
responsibility for any damage or injury that results from the use of any tool or parts
not sold or approved by NPK.
For further safety information, consult the AEM Hydraulic Mounted Breakers Safety
Manual, AEM form MB-140 (NPK P/N H050-9600), which is furnished with every NPK
hammer. To request an additional copy, please contact NPK at 800-225-4379 or
Internet at www.npkce.com.

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INTRODUCTION
NPK is a leading manufacturer of HYDRAULIC HAMMERS, and has the most complete
product line available anywhere. The success of NPK is due to our commitment to
quality, dependability and long life. The HYDRAULIC HAMMER has many unique
designed features and it is a company philosophy that the NPK HYDRAULIC HAMMER
can be brought to "like new” condition long after competitive products are scrapped.
You can feel confident that you have purchased the best value available.
This comprehensive operator’s manual contains instructions for operating and
maintaining NPK HYDRAULIC HAMMERS. This manual includes helpful information for
obtaining the full potential and efficiency from NPK HYDRAULIC HAMMERS. Please
read this manual thoroughly to understand the NPK HAMMER and its operating
principles before using it.
For additional information or help with any problem encountered, please contact your
NPK authorized dealer.
Whenever repair or replacement of component parts is required, only NPK parts should
be used. NPK is not responsible for failures resulting from substitution of parts not sold
or approved by NPK.
This manual will also assist NPK Dealers and Customers to obtain the longest possible
life from the NPK Demolition Tools.
Customers can use this manual to take corrective action when tool breakage occurs.
Dealers can use this manual to determine if tool breakage can be claimed under
warranty.
Refer to the NPK Demolition Tool Warranty statement found later in this manual for the
specifics of the warranty coverage.

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CARRIER MACHINE COMPATIBILITY
These carrier weight ranges are intended as a guideline only. Other factors, such as
stick length, counterweights, undercarriage, etc., must be taken into consideration.
Mounting a HAMMER that is too heavy for the carrier machine
can be dangerous and damage the machine. Verify carrier
stability with hammer before transport or operation.
Mounting a HAMMER that is too small for the carrier machine can damage the
HAMMER, cause tool breakage and void Warranties. Please consult NPK Engineering
for specific detailed information.
CARRIER WEIGHT lbs. (kg)
HAMMER MOUNTING RECOMMENDED RANGE
MODEL STYLE (lb) (kg)
GH3-2 Excavator 8,800 – 15,000 4,000 – 7,000
Skid Steer 8,000 – 14,000 3,600 – 6,400
*Specifications are subject to change without notice.

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HAMMER SPECIFICATIONS
HAMMER
MODEL IMPACT ENERGY
CLASS
FREQUENCY WORKING WEIGHT MOUNTING STYLE TOOL
DIA WORKING
LENGTH
ft lb bpm lbs (Kg) in (mm) in (mm)
GH3-2 750 500 – 1150 1075 (490) Skid Steer 3.0 (76) 16.1 (408)
800 (365) Excavator
HAMMER
MODEL OIL FLOW HYDRAULIC OPERATING
PRESSURE 1
CIRCUIT
RELIEF
minimum 2
GAS CHARGE
PRESSURE 5
Cold 3Hot
4
gpm (L/min) psi (bar) psi (bar) psi (bar) psi (bar)
GH3-2 12 – 26 (45 – 100) 1900 (130) 2400 (165) 350 (24) 405 (28)
*Specifications subject to change without notice.
NOTES:
1. Hydraulic operating pressure maximum is inlet pressure at the hammer with the oil at
operating temperature and with the gas charge set at the hot operating pressure. See
CHECKING THE HYDRAULIC PRESSURES section in the Service Manual.
2. Circuit relief pressure is at least 500 psi (35 bar) above hammer operating pressure.
3. Cold gas charge is the initial set with the hammer at ambient temperature.
4. Hot gas charge is checked after 1 to 2 hours of running and with a system oil temperature of
140to 180F (60to 80C). This is the preferred check.
5. Pressures listed are maximum. Use tolerance of minus 25 psi (2 bar).

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HAMMER SERIAL NUMBER LOCATION
SERIAL NUMBER LOCATION (sn1)

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HYDRAULIC INSTALLATION
NPK can produce INSTALLATION KITS for virtually all compatible backhoe loaders,
excavators, and skid steers. Complete parts and instructions for the hydraulic
installation of the NPK HYDRAULIC HAMMER including valving and/or controls, hoses
and fittings, boom and stick tubing, and clamps are provided.
HAMMER LINES
Typically, the pressure line is arranged on the left side of the boom and the return line
on the right side. Flow to the hammer is controlled from an auxiliary valve on the carrier
or from an NPK supplied valve. Hydraulic oil, generally, is routed back to the tank thru
the carrier’s oil cooler and filter.
HAMMER CONTROL VALVE
NPK uses two general types of control systems, depending upon the carrier model:
1. CONTROL SYSTEM USING THE CARRIER AUXILIARY OR SPARE VALVE
SECTION.
This type of installation utilizes an existing carrier valve. Any additional parts, such
as a mechanical linkage, hydraulic pilot actuators, flow control valves, etc., are
furnished in the NPK HYDRAULIC INSTALLATION KIT. Special hydraulic pressure
control valves are not required. The NPK HYDRAULIC HAMMER operating
pressure is self-regulating.
2. CONTROL SYSTEM USING THE NPK MULTIVALVE.
For carriers not equipped with a suitable auxiliary or spare valve section, the NPK
HYDRAULIC INSTALLATION KIT includes a solenoid operated, priority flow control
valve to operate the NPK HYDRAULIC HAMMER. The NPK MULTIVALVE is
specifically designed for the operation of boom mounted attachments.

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HYDRAULIC INSTALLATION
PREVENTION OF CONTAMINATION
1. A hydraulic hammer is harder on oil than using a bucket, so the oil is apt to
deteriorate and breakdown sooner. Neglect of the oil system can not only damage
the hydraulic hammer but also cause problems in the carrier which could result in
damaged components. Care should be taken to check for contamination of the oil
and to change it if it is found contaminated. Oil sampling at regular intervals is
highly recommended.
When the hydraulic oil shows low viscosity and bubbles, this indicates that the oil
is deteriorated. If the oil is dark brown and gives off an offensive odor, it is
severely deteriorated. Change the oil immediately!
When the oil is clouded, or the oil filter has become clogged, it indicates that the
oil is contaminated. Change the oil immediately!
To change the contaminated hydraulic oil, drain the hydraulic system completely
and clean components. Do not mix new oil with the old.
2. Do not allow any contamination to mix with the oil. Take special care in preventing
contamination from entering the hydraulic system through the hose or tube
connection when changing the hydraulic hammer with the bucket.
3. Low oil level will cause heat build-up, resulting in deterioration of the oil. Also, it may
cause cavitation due to air mixing with the oil, leading to a damaged hydraulic
hammer and carrier components. Keep the oil at the proper level at all times.
4. Do not use the hydraulic hammer at an operating temperature higher than 180°F
(80°C). The proper operating oil temperature range is between 120°F (50°C) and
180°F (80°C). Since contaminated cooler fins causes reduced efficiency of the
cooler, keep the cooler fins clean at all times. Check the hydraulic oil cooling system
to be sure it is working effectively. The use of a heat gun is the best way to evaluate
if the cooler is working properly.
5. Water in the hydraulic oil will lead to damage of the hydraulic hammer and carrier.
Drain off water and foreign matter from the hydraulic tank at specified intervals.
When out of service, the hydraulic hammer should be stored indoors.
CHANGING THE FILTER ELEMENT AND HYDRAULIC OIL
Change the filter element and hydraulic oil at the intervals described in the operation
manual of the skid steer or excavator, when using a hydraulic implement. Another
method is to set up an oil sampling schedule and change accordingly.

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HYDRAULIC INSTALLATION
HYDRAULIC QUICK DISCONNECTS
NPK recommends against the use of non-NPK quick
disconnects on hydraulic circuits operating NPK Products.
1. The hydraulic pulsations caused by hydraulic hammer operating can cause internal
pieces of non-NPK quick disconnect to disintegrate. These pieces would migrate
into the hammer, causing damage.
2. If quick disconnects are not used when the hammer is removed from the excavator,
the quick disconnects should be capped to keep them clean. If this is not done,
contamination in the disconnect will be flushed into the hammer when re-connected.
This, again, can cause damage.
3. Most quick disconnects create a restriction in the circuit. NPK Hammers are not
back pressure sensitive, but restrictions cause unnecessary heating of the oil. Also,
the pressure required to operate the hammer, plus the restriction in the disconnects
may push an older, low pressure, carrier machine to the limit of its hydraulic system.
This would interfere with proper hammer operation. However, the NPK approved
quick disconnects are properly sized so that the hammer operation is not
affected.
APPROVED CONNECTION (39) NOT RECOMMENDED CONNECTION Non-NPK Quick Disconnects (32)
NPK APPROVED CONNECTION QUICK DISCONNECTS (DX)
CONTACT YOUR NPK DEALER FOR ADDITIONAL INFORMATION ABOUT
NPK QUICK DISCONNECTS

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HYDRAULIC INSTALLATION
HYDRAULIC QUICK DISCONNECTS
If hydraulic quick disconnects are used with the NPK Hammer, it is recommended that
the following precautions be followed.
1. Periodic inspection of both male
and female ends is recommended
to ensure the couplers are in good
working condition. Failure to
inspect couplers may result in
pieces from a damaged or failed
coupler to be injected into the
hammer or parts of the coupler
returned to the machine.
2. Check for dirt, dust, and debris on
both couplers (32) before coupling.
3. Be sure that the couplers are
completely seated together (38).
4. When replacing couplers, be sure
that couplers are replaced as a set,
male and female. Do not use one
new end and one used end.

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MOUNTING INSTALLATION
NPK Mounting Installation Kits include the parts required to adapt the NPK HYDRAULIC
HAMMER to the carrier. NPK mounting kits include the hammer mounting bracket,
flow control valve (if required), and hoses to connect to the carrier hydraulic system.
AF Hex Head Cap Screw (if required)
CB Male Adapter (if required)
CI Hex Nut (if required)
FX Male Quick Disconnect (if required)
FY Female Quick Disconnect (if required)
m1 Stick Pin (if required)
m2 Link Pin (if required)
m3 (Whip) Pressure Hose
m4 (Whip) Return Hose
m7 Top Bracket
m8 Hammer Bolt Package
m9 Klik Pin (if required)
REMOVAL FROM THE CARRIER
1. Close pressure and return line shut-
off valves.
2. Disconnect hydraulic hoses (m3 &
m4) before laying the hammer down.
3. Cap the pressure and return lines on
the carrier and connect the hammer
whip hoses.
4. Position the hammer (DR) horizontal
on wood blocks (t20) and remove
boom pins (m1 and m2).
The hydraulic lines must be handled carefully and sealed to
prevent contamination from entering the hammer or the carrier
hydraulic system.
The tool end of the hammer should be set lower than the head
end to prevent moisture from entering the hammer through the
tool area.
MOUNTING TO THE CARRIER
1. Place the hammer horizontal on
wood blocks (t20), as shown.
2. Align the boom pin holes (m1).
Install the stick pin before the
cylinder link pin.
3. Connect hydraulic hoses.
PRESSURE is on left, RETURN is
on right.
4. Open shut-off valves.

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SWITCH HAMMER TO ANTI-BLANK FIRE
1. Place the hammer horizontal to the ground.
2. Turn the shut-off valves (PRESSURE and RETURN) on the carrier to the OFF
position (to prevent oil flow from the carrier).
3. Exchange the long plug (AS5) with the short plug (AS4) which are both attached to
the side of the hammer body.
a. To put it into the anti-blank mode, insert the short plug (AS4) into the lower port
(126) and the long plug (AS5) into the upper port (127).
b. To put it into the standard mode, insert the long plug (AS5) into the lower port
(126) and the short plug (AS4) into the upper port (127).
4. Turn the shut-off valves (PRESSURE and RETURN) to the ON position.
DO NOT switch the plugs when the hydraulic oil is hot! Serious injury can occur!

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LUBRICATION
GREASING PROCEDURE
1. Place the hammer in a vertical position, applying enough downforce to push the tool
up into the hammer.
2. Turn the machine off.
3. Grease the hammer until grease begins to come out around the tool and lower
bushing.
4. Grease hammer at least once an hour. See “Correct Grease and Grease Intervals”
for a more exact greasing procedure.
APPLY DOWNFORCE TO PUSH TOOL UP INTO HAMMER
NOTE: USE A GOOD QUALITY EP #2 LITHIUM BASED GREASE WITH WEAR
INHIBITING ADDITIVES, SEE PAGES 15, 16, AND 17.

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LUBRICATION
CORRECT GREASE AND GREASE INTERVALS
Proper hammer maintenance requires a sufficient supply of the correct grease to the
tool (chisel). The tool must be pressed against a hard surface until it stops up inside the
hammer. This prevents grease from entering piston impact area and ensures proper
distribution of grease between the tool and tool bushings.
GREASE INTERVALS
The hammer must be greased at regular intervals to get the best life from the tool and
tool bushings. There are two ways to determine grease intervals:
First, grease the hammer at the beginning of the job until grease comes out between
the tool and the lower tool bushing. Run the hammer until the shank of the tool starts to
look dry. This determines the time interval for the greasing of this particular hammer on
this particular job. Typically, this is 1 to 4 hours. Also, note the amount of grease
needed to re-grease the tool. This gives you the amount of grease and how often it
must be applied. An example would be that a particular hammer, on a particular job,
requires half a tube of grease every 3 hours. This would be the greasing schedule you
would set up. If this hammer was moved to another job, another grease schedule may
have to be determined.
Second, if you can’t control the grease schedule, such as rental units, then have the
operator grease the hammer once every hour of hammer operation. Again, grease the
hammer until grease comes out between the tool and tool bushing. This is usually more
often than required, but is far cheaper than replacing prematurely worn tools and tool
bushings.
CORRECT GREASE
The type of grease used is very important. NPK recommends a lithium soap base EP
(Extreme Pressure) NLGI #2 Grease, with Moly (Molybdenum Disulfide) or other
surface protecting additives. A high drop point (500° F, 260° C) grease is desirable.
On the following page is a list of commonly available greases, by manufacturer and
brand name that meet NPK’s recommendations. NPK does not endorse any one brand
as being superior to another. If you or your customers use a brand not listed, please
call the NPK Service Department at 800-225-4379.

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LUBRICATION
CORRECT GREASE FOR HYDRAULIC HAMMERS
MANUFACTURER BRAND NAME
Amalie Oil Co. LI-2M
Amoco Rykotac EP Grease
Amolith Grease 94601
Rykon Premium Grease EP (Grade 94108)
Rykon Premium Moly Grease (Grade 94114)
Amoco Molylith Grease 92006
Amsoil, Inc. GHD
BP Oil, Inc. Bearing Gard-2
Caterpillar Multipurpose Molydbenum Grease (MPGM)
Cato Oil and Grease Company Moly Lithflex CX AS
CITGO Citgo Extra Range Grease
Conoco, Inc. Super Lube M EP #2
Dryden Oil Company Moly EP 2
Exxon Ronex Extra Duty Moly NLGI 2
Fiske Brothers Refining Co. (Lubriplate) MO-LITH No. 2
John Deere TY6333/TY6341 Moly High Temp
Kendall L-424
Mobil Moly 372
Muscle Products Corporation (MPC) PL-10 Powerlift Grease
LP-10 Lithium EP Plus
NPK Universal Plus Lithium EP Grease
Super Duty EP Grease (water resistant)
Chisel Paste
Pennzoil Adhezolith EP 2 Grease
Phillips 66 Company Philube MW
Shell Retinax ® AM Grease 71119
Retinax ® HD Grease
Standard Oil Company Bearing Gard-2
Sun Refining & Marketing Company Prestige Moly 2 EP
Texaco, U.S.A. Molytex EP 2
Union Oil Company Unoba Moly HD #2
Unocal Unoba Moly HD #2

- 17 -
LUBRICATION
CORRECT GREASE FOR HYDRAULIC HAMMERS
NPK HAMMER GREASE
NPK now offers hammer grease specially formulated to meet severe job requirements.
The grease is available in three different temperature ranges - 350°, 500°, and 2000°.
Universal Plus and Super Duty are lithium soap based products that resists washout
and contain NPK-10 additive for surface protection in friction affected areas.
Chisel Paste is an aluminum complex soap base with 12% graphite and copper
additives for extreme operating conditions.
UNIVERSAL PLUS
350 deg NPK PART NO.
14 OZ. CARTRIDGE G000-1010
120 LB. KEG G000-1020
35 LB. PAIL G000-1030
400 LB. DRUM G000-1040
SUPER DUTY
500 deg NPK PART NO.
14 OZ. CARTRIDGE G000-1011
120 LB. KEG G000-1021
35 LB. PAIL G000-1031
400 LB. DRUM G000-1041
CHISEL PASTE
2000 deg NPK PART NO.
14 OZ. CARTRIDGE G000-1050

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LUBRICATION
LUBRICANT TERMS AND DEFINITIONS
TERM DEFINITION
ADHESIVE The ability of grease, gear lubricant or oil to cling to
metal.
ANTI WEAR AGENTS Used to help combat metal-to-metal contact, thus
reducing wear.
COHESIVE The ability of grease, gear lube or oil to cling to itself,
thus resisting tearing apart.
CONSISTENCY Consistency of grease is its hardness or firmness. It is
determined by the depth in millimeters to which the cone
of a penotrometer sinks into a sample under specified
conditions. Consistency of grease may be influenced by
the type and amount of thickener, viscosity of oil, working
and other factors.
CONTAMINATION Foreign material that could damage a part.
DROPPING POINT The minimum temperature at which the oil in a grease
subjected to heat begins to actually drip and breakdown.
EXTREME PRESSURE
AGENTS Additives that under extreme pressure form an adherent
film on metal surfaces, thus forming a film of protection.
FILM STRENGTH Film strength is defined as the tendency of oil molecules
to cling together. It is the ability of those molecules to
resist separation under pressure between two metals and
to hold these metal surfaces apart.
FRICTION The resistance to fluid flow in a hydraulic system. (An
energy loss in terms of power output.)
GALLING Surface damage on mating, moving metal parts due to
friction. A severe form of adhesive wear.
LUBRICATION Use of a substance (grease, oil, etc.) to reduce friction
between parts or objects that move against each other.
NLGI A rating given to a grease from the National Lubricating
Grease Institute. This rating determines the hardness of
the grease and goes on from a 000 to a 6 rating. Most
greases are NLGI #2 rated.
OILINESS Oiliness is measured of the coefficient of friction of a
lubricant. Oiliness or lubricity depends on the adhering
characteristics of an oil. It is determined by the attraction
between the molecules of the oil and the molecules of
another material. Of two oils having the same viscosity
but different degrees of fluid friction, the one with the
lower friction index has the higher degree of oiliness.
PUMP A device which converts mechanical force into hydraulic
fluid power. Basic design types are gear, vane, and
piston units.

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LUBRICATION
LUBRICANT TERMS AND DEFINITIONS
TERM DEFINITION
RESERVOIR A container for keeping a supply of working fluid in a
hydraulic system.
VIBRATION A quivering or trembling motion.
VISCOSITY Is the actual SAE weight of the product. Example motor
oils come in 10, 20, 30, 40, 50 and 15/40 SAE weight.
The viscosity designation of a lubricant indicates its
internal resistance to flow.