Buffalo Tools HIT125 Quick reference guide

ITEM # HIT125
80A MIG Welder
Assembly & Operating Instructions
READ ALL INSTRUCTIONS AND WARNINGS BEFORE USING THIS PRODUCT.
This manual provides important information on proper operation & maintenance. Every effort has been made to
ensure the accuracy of this manual. These instructions are not meant to cover every possible condition and situation
that may occur. We reserve the right to change this product at any time without prior notice.
IF THERE IS ANY QUESTION ABOUT A CONDITION BEING SAFE OR UNSAFE, DO NOT OPERATE
THIS PRODUCT!
HAVE QUESTIONS OR PROBLEMS? CONTACT CUSTOMER SERVICE.
If you experience a problem or need parts for this product, visit our website http://www.buffalotools.com or call our
customer help line at 1-636-532-9888, Monday-Friday, 8 AM - 4 PM Central Time. A copy of the sales receipt is
required.
FOR CONSUMER USE ONLY – NOT FOR PROFESSIONAL USE.
KEEP THIS MANUAL, SALES RECEIPT & APPLICABLE WARRANTY FOR FUTURE REFERENCE

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RECOGNIZE SAFETY SYMBOLS, WORDS AND LABELS
What You Need to Know About Safety Instructions
Warning and Important Safety Instructions appearing in this manual are not meant to cover all possible conditions
and situations that may occur. Common sense, caution and care must be exercised when operating or cleaning
tools and equipment.
Always contact your dealer, distributor, service agent or manufacturer about problems or conditions you do not
understand.
This is the safety alert symbol. It is used to alert you to potential
personal injury hazards. Obey all safety messages that follow
this symbol to avoid possible injury or death.
DANGER indicates an imminently hazardous situation
which, if not avoided, will result in death or serious
injury.
WARNING indicates a potentially hazardous situation
which, if not avoided, could result in death or serious
injury.
CAUTION indicates a potentially hazardous situation
which, if not avoided, may result in minor or moderate
injury.
CAUTION used without the safety alert symbol
indicates a potentially hazardous situation which, if not
avoided, may result in property damage.

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SAFETY
Welding is dangerous, and may cause damage to you and others, so wear protection when
cutting.
Professional training is needed before operating the machine.
!Always wear ANSI-approved eyewear and protective equipment while operating this unit.
!The operator must be qualified personnel with a valid "metal welding/cutting (OFC)
operations" operation certificate.
!Cut off power before maintenance or repair.
WARNING: Electric shock—may lead to serious injury or even death.
!Install earth device according to the application criteria.
!Never touch the live parts when skin bared or wearing wet gloves/clothes.
!Make sure that you are insulated from the ground and workpiece.
!Make sure that your working position is safe.
WARNING: Smoke & gas may be harmful to health.
!Keep the head away from smoke and gas to avoid inhalation of exhaust gas from welding.
!Keep the working environment in good ventilation, use exhaust or ventilation equipment when
welding.
Arc radiation—may damage eyes or burn skin.
!Wear suitable cutting masks and protective clothing to protect your eyes and body.
!Use suitable masks or screens to protect spectators from harm.
Improper operation may cause fire or explosion.
!Welding sparks may result in a fire, so please make sure no combustible materials nearby
and pay attention to fire hazard.
!Have a fire extinguisher nearby, and have a trained person to use it.
WARNING: Hot workpiece may cause severe scalding.
!Do not contact hot workpiece with bare hands.
!Cooling is needed during continuous use of the welding torch.
Magnetic fields affect cardiac pacemaker.
!Pacemaker users should be away from the welding spot before medical consultation.
Moving parts may lead to personal injury.
!Keep yourself away from moving parts such as fan.
!All doors, panels, covers and other protective devices should be closed during operation.

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HIT125 is a gasless (use flux wire) MIG welder.
Specifications
ITEM
HIT125
Power voltage (v)
120
Frequency (HZ)
60
Max no load voltage output (V)
31
Output current (A)
30-80A
Duty cycle
80A@30%
Suitable wire dia. (INCH)
.030 - .035”
Insulation class
F
Protection class
IP21S
Suggested Wire: Flux Cored Wire
Use Without Shielding Gas
Welds Carbon Steel Between 1.2mm-3.0mm
Overload & Thermal Protection
Includes MIG Torch, Grounding Cable & Earth Clamp, Wire Spool, Clipping Hammer / Brush & Welding
Face Shield
Welding Material: All types of carbon steel.

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Assembly
CAUTION ! ! ! !
1. WORKING ENVIRONMENT
1）BEST TO WORK IN DRY PLACES, NOT TOO WET OR RAINY OR FULL OF DUST ETC.
2）KEEP TEMPERATURE BETWEEN 14°F TO 140°F.
2. SAFETY
1）Please keep the machine cool, make sure the fan is working and not blocked.
2）The working voltage is AC 120V±15%, if lower or higher than this, it will cause damage.
3）The welder will automatic recover and work again when cooled down.
3. USE CORRECT CONSUMABLES
During welding, the working temperature is very hot and will cause the head of torch to be easily damaged. Please
change often.

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Installation
1. Power requirement
AC single phase 120v (110-120V), 60HZ with a 20 amp time delayed fuse or circuit breaker is required.
DO NOT OPERATE THIS UNIT if the ACTUAL power source voltage is less than 105 volts AC or greater than
132 volts AC.
• High voltage danger from power source! Consult a qualified electrician for proper installation of receptacle. This
welder must be grounded while in use to protect the operator from electrical shock.
• Do not remove grounding prong or alter the plug in any way. Do not use any adapters between the welder’s
power cord and the power source receptacle. Make sure the POWER switch is OFF when connecting your
welder’s power cord to a properly grounded 120Vac, 60Hz, single phase, 20 amp power source.
2. Extension cord
It is strongly recommended that an extension cord should not be used because of the voltage drop it produces.
This drop in voltage can affect the performance of the welder. If you need to use an extension cord it must be a
#12 gauge cord or larger. Do not use an extension cord over 25 ft. in length.
3. Install the wire roller
Before installing any welding wire into the unit, the proper sized groove must be placed into position on the wire
drive mechanism. Adjust the drive roller according to the following steps, see following picture of the wire feed
mechanism:
3.1. Open the door to the welder drive compartment.
3.2. (see #1) Loosen the tension adjusting wing nut and lifting the Drive Tension Adjustor away from the Drive
Tension Arm (see #2). Pull the drive tension arm away from the wire roller.
3.3. If there is wire already installed in the welder, roll it back onto the wire spool by hand-turning the spool
counterclockwise. Be careful not to allow the wire to come out of the rear end of the inlet guide tube without holding
onto it or it will unspool itself. Put the end of the wire into the hole on the outside edge of the wire spool and bend it
over to hold the wire in place. Remove the spool of wire from the spool hub by removing the drive tensioning wing
nut and hardware.

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#2
3.4. Open the machine door using the “L” type six angle wrench, counterclockwise unscrewing the screw drive
roller on the wire, and remove the drive roller.
3.5 Based on the wire diameter, select the correct groove using the following table:
Wire Diameter
Roller Groove
.030 inch
0.8
.035 inch
0.9
The drive roller has two wire size grooves. When installing the drive roller, the number stamped on the drive roller
for the wire size you are using should face in. This identifies the inside groove the wire will line up with. Assemble
the drive roller onto the drive roller shaft

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4. Install the wire
4.1 Selecting the wire . Available wire for this machine : (Four inch spools are available.)
Wire Type
Available
MIG wire .023 inch
Yes
MIG wire .030 inch
Yes
Flux core wire .030 inch
Yes
Flux core wire .035 inch
Yes
NOTE:
• Burn through will occur if you attempt to weld mild or stainless steel thinner than 24 gauge.
• Remove all rusted wire, if the whole spool is rusty discard it.
4.2 Install the wire
Electric shock can kill! Always unplug the power cord from the AC power source before installing wire.
NOTE:
• Before installing, make sure that you have removed any old wire from the torch and cable assembly. This will help
to prevent the possibility of the wire jamming inside the Gun Liner.
• Be careful when removing the welding nozzle. The contact tip on this welder is live when the gun trigger is pulled.
Make certain POWER is turned OFF.
4.2.1 Remove the nozzle and contact tip from the end of the gun assembly. See following images for reference
4.2.2 Make sure the proper groove on the drive roller is in place for the wire to be installed. If not, change the drive
roller as described above.
4.2.3 Remove the packaging from the spool of wire and then identify the leading end of the wire secured in a hole
on the edge of the spool. DO NOT UNHOOK IT AT THIS TIME.
4.2.4 Place the spool on the spool hub with the wire coming off the bottom of the spool. The bottom of the spool
aligns with inlet to the drive system for smooth flow of the wire. See following figure.

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4.2.5 The welder can use 4 inch spools only. The wing nut controls the tension on the spool.
4.2.6.
Setting the wire spool tension:
a) Turn the spool of wire with one hand.
b) Increase the spool tension by tightening (turn clockwise) the wing nut while
turning the spool. Turn the spool while tightening the wing nut until the spool
slows down and operator feels a slight drag.
Stop tightening the wing nut, operator may need to repeat these steps until proper
spool tension is achieved.
NOTE:
If TOO MUCH tension is applied to the wire spool, the wire will slip on the drive roller or will not be able to feed at
all. If TOO LITTLE tension is applied, the spool of wire will want to unspool itself when the trigger is released.
Readjust the spool tension using the wing nut as necessary to correct for either problem.
4.2.7.After checking to make sure that your welder is disconnected from the AC power source, free the leading end
of the wire from the spool, but DO NOT LET GO OF IT until it is secure in the drive system or the wire will unspool
itself.
4.2.8. Using a wire cutter, cut the bent end off the leading end of the wire so that only a straight leading end
remains.
4.2.9. Loosen the tension adjusting knob holding the drive tension arm in place and lift the tension arm up off the
drive roller.
4.2.10. Insert the leading end of the wire into the inlet guide tube. Then push it across the drive roller and into the
MIG gun/torch assembly about six inches.
• Make certain that the welding wire is actually going into the torch liner. If not, the wire will jam in the mechanism.
4.2.11 Be sure the wire lines up in the groove of the drive roller then place the drive tension arm back in place
above the drive roller.
4.2.12 Position the quick release drive tension back up into position into the drive tension arm.
4.2.13 Tighten (turn clockwise) the drive tension adjusting knob until the tension roller is applying enough force on
the wire to prevent it from slipping out of the drive assembly. Do not over tighten.
4.2.14. NOW YOU CAN LET GO OF THE WIRE.
4.2.15. Plug in and turn the welder ON. Set the VOLTAGE switch to the voltage (heat) setting recommended for
the gauge metal that is to be welded. Refer to the set up chart on the inside of the wire feed compartment door.
4.2.16. Set the WIRE SPEED control in the middle of the wire speed range.
8.17. Straighten the MIG gun cable, pull the trigger on the welding torch to feed the wire through the torch
assembly. When at least one inch of the wire sticks out past the end of the torch, release the trigger.
4.2.18 Turn the Power Switch to the OFF position.
4.2.19 Select a contact tip stamped with the same diameter as the wire being used.
Wing nut
8” wire
spool

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NOTE:
Due to inherent variances in flux-cored welding wire, it may be necessary to use a contact tip one size larger than
your flux core wire if wire jams occur.
4.2.20. Slide the contact tip over the wire (protruding from the end of the gun). Thread the contact tip into the end of
the gun adaptor and tighten securely.
4.2.21. Install the nozzle on the gun assembly. To keep spatter from sticking to inside of the nozzle use
anti-spatter spray or gel.
4.2.22 Cut off the excess wire that extends more than ¼” past the end of the nozzle.
4.2.23. Turn the welder ON
5. Setting the wire tension
Arc flash can injure eyes! To reduce the risk of arc flash, make certain that the wire coming out of the end of the
torch does not come in contact with work piece, ground clamp or any grounded material during the drive tension
setting process or arcing will occur.
5.1. Press the trigger on the torch.
5.2. Turn the drive tension adjustment knob clockwise, increasing the drive tension until the wire seems to feed
smoothly without slipping.