AGM 250C User manual

AGM Pin Welder
Instruction Manual
Model 250C
AGM Industries, Inc.
16 Jonathan Drive, Brockton, MA 02301
TEL: [phone] FAX: [phone]
www.agmind.com
Read equipment manufacturer’s manual before using this product. Failure to do so can result in
serious injury or death.

2
TABLE OF CONTENTS
Subject Page
1. Description of accessories 3
2. Installing & removing collets, stops, etc. 5
3. Disassembly of weld gun 10
4. Diagram & parts list 11
5. Weld gun Set-Up Sheets
Welding Steel and Stainless Steel weld pins 12
Welding Aluminum weld pins 13
Welding pins over 7” long 14
Welding flanged Steel and Stainless Studs up to 1/4-20 diameter 15
Welding flanged and Non-Flanged Aluminum studs. Non-flanged 16
Steel and Stainless studs through 1/4-20 diameter. (All
welders except JS-1 320SS & LS-400)
Welding Non-Flanged Steel and Stainless Studs through 1/4-20 17
diameter (JS-1,320SS & LS-400 only)
Alternate set-up for welding studs over 1-3/8” long 18
Welding studs 5/16” diameter and larger 19
Welding Cupped head/Mini-cup Pins 22
Welding Powerbase Pins 25
Welding to a curved surface 27
Welding through a template 28
Spec. for a typical template 29
6. Approximate Voltage Settings & Ground Polarity
Mild or Stainless Steel base / Mild or Stainless Steel pins or studs 30
Galvanized Steel base / Mild or Stainless Steel pins or studs 31
Aluminum base / Aluminum pins or studs 32

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Model 250C Weld Gun
The AGM Model 250C weld gun is a semi-automatic, contact welding tool that has been
carefully engineered and designed for use with a wide variety of AGM accessories.
Given normal care and use, this weld gun will require very little maintenance. When
repairs are required, the complete disassembly of the weld gun can be accomplished in a
matter of minutes.
Following is a description of the various accessories available. The application sheets list
the recommended accessories and their part numbers.
COLLET* - This is always required for welding. It is very important that the correct
size be used and that it is in good condition. A loose fitting collet will cause arcing on
the stud or pin and possibly cause poor welds.
COLLET PROTECTOR* - This is used when welding flanged studs or weld pins. It
allows you to weld various lengths of studs or pins without changing the gun set up. It
also helps to keep splatter away from the collet. It is important the collet protector be
used whenever recommended. Protectors are not required when using stops, except when
welding Powerbase pins.
STOP* - This is required when welding non-flanged studs, or when the adjustable foot
assembly is used. Its purpose is to back up the pin or stud to prevent it from being
inserted too far into the gun. The Model 250C gun utilizes two types of stops; the 437G
and the 250C-G. Both are easily installed.
COLLET ADAPTER ASSEMBLY - This is used as a holder for the collets, stops and
collet protectors. It allows for rapid interchange of collets and it is easily removed by the
tapered wedge that is supplied with the gun.
It has been found to be good practice to keep extra collets, protectors, stops and adapters
on hand.
LEGS - They are used to provide correct weld gun spring pressure while keeping the
stud or pin perpendicular to the work. They are normally mounted 120 degrees apart on
the weld gun face plate.
LEG SUPPORT RING - This is used when welding on a curved surface, such as
corrugated metals or round tanks. It is placed over the three legs, and aligns the stud or
pin when the ring is held firmly against the work.
ADAPTER RING - This is used to extend the three legs for certain applications, such as
when a longer collet protector is used to weld aluminum pins.
* Specify stud or pin diameter and length when ordering.

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(CONTINUED)
Model 250C Weld Gun
(CONTINUED)
ADJUSTABLE FOOT ASSEMBLY - This is necessary when welding Powerbase pins
and large diameter studs and may also be used for welding very long CD pins. It is used
in conjunction with a stop and spark shield to stabilize the pin or stud.
SPARK SHIELD* - This protects the collet, collet adapter assembly, etc. from weld
splatter, while stabilizing the pin or stud during the weld cycle. It will require occasional
cleaning and periodic replacement.
* Specify stud or pin diameter and length when ordering.

5
Model 250C Weld Gun
(CONTINUED)
INSTALLATION AND REMOVAL PROCEDURES
INSTALLING COLLET AND COLLET PROTECTOR
A. Examine the inside of the collet adapter assembly for pitted areas or splatter.
Clean by scraping with a sharp object, or replace if necessary.
B. Insert the collet into the collet adapter assembly, making sure that it seats against
the shoulder.
C. Locate the two (2) collet holding set screws and tighten them securely. These
screws should be checked daily for tightness.
D. Slide the collet protector over the collet adapter assembly, making sure that it
seats properly. Tighten the set screws securely.
COLLET REMOVAL
A. Remove the collet protector by loosening the two (2) protector holding set screws
approximately 1-1/2 turns.
B. Loosen both collet holding set screws approximately 1-1/2 turns.
C. Grasp the collet by its end and remove it.
If you have difficulty removing the collet, the following procedures may be
helpful:
1. Manually rotate the collet.
2. Insert the proper size stud or pin into the collet and attempt to remove the
collet and fastener together.
3. If the above suggestions do not work, pliers may be used. Insert the
proper size pin or stud into the collet and rotate until the collet is loose.

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Model 250C Weld Gun
(CONTINUED)
INSTALLING TYPE 437G STOP
A. Place the stop inside the rear of the collet.
B. Insert the collet, with stop, into the collet adapter assembly.
C. Locate and tighten the collet holding set screws, as previously described.
D. DO NOT use a collet protector.
INSTALLING TYPE 250C-G STOP
A. Remove end cap and stop nut from rear of weld gun.
B. Insert stop inside gun shaft.
C. Screw stop nut down securely over the end of the shaft.
D. Replace end cap onto gun housing.
E. DO NOT use a collet protector.
F. See chart on the next page for stop numbers.

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250C-G TYPE STOP
STUD LENGTH CATALOG NUMBER STOP LENGTH
1/4” – 5/16” 250C-G-*-0250 7”
3/8” – 7/16” -0375 6.875”
1/2” – 9/16” -0500 6.750”
5/8” -0625 6.625”
3/4” -0750 6.500”
7/8” -0875 6.375”
1” -1000 6.250”
1-1/4” -1250 6.000”
1-1/2” -1500 5.750”
1-3/4” -1750 5.500”
1-7/8” -1875 5.375”
2” -2000 5.250”
2-1/4” -2250 5.000”
2-1/2” -2500 4.750”
2-3/4” -2750 4.500”
2-7/8” -2875 4.375”
3” -3000 4.250”
3-1/4” -3250 4.000”
3-1/2” -3500 3.750”
3-7/8” -3875 3.375”
4” -4000 3.250”
4-1/2” -4500 2.750”
4-7/8” -4875 2.375”
5” -5000 2.250”
5-1/2” -5500 1.750”
5-7/8” -5875 1.375”
6” -6000 1.250”
6-1/2” -6500 0.750”
7” -7000 0.250”
437G TYPE STOP
STUD LENGTH CATALOG NUMBER STOP LENGTH
** 3/16” 437G-*-0187 1.230”
** 1/4” -0250 1.168”
** 5/16” -0312 1.106”
** 3/8” -0375 1.043”
7/16” -0437 0.981”
1/2” -0500 0.918”
9/16” -0562 0.856”
5/8” -0625 0.793”
3/4” -0750 0.668”
7/8” -0875 0.543”
1” -1000 0.418”
1-1/8” -1125 0.293”
1-1/4” -1250 0.168”
1-3/8” -1375 0.043”
*Specify diameter of stud (i.e. 6-32, 8-32, 10-32 etc.)
** Requires 375-SP series collet for studs 3/8” long and shorter.

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MODEL 250-C WELD GUN
INSTALLATION OF COLLET ADAPTER ASSEMBLY
This procedure can be accomplished with a collet and stop, or collet protector already
installed.
A. Before installing, be sure that the tapered surface of the collet adapter and shaft
assembly are clean. Wipe with a clean cloth if necessary.
B. Insert the collet adapter assembly into the shaft assembly, turning the adapter as it
is pushed down. This will ensure that it is seated securely.
REMOVAL OF COLLET ADAPTER ASEMBLY
A. Slide the rubber dust boot toward the faceplate to expose the shaft assembly.
B. Insert the tapered wedge between the shaft assembly and the collet adaptor
assembly. The flat side of the wedge should go toward the shaft.
C. Tap the wedge lightly to release the adapter assembly from the tapered seat of the
gun shaft.

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MODEL 250-C WELD GUN
INSTALLING OR CHANGING SPRING
A. Unscrew the end cap from the gun housing.
B. Unscrew stop nut from the end of gun shaft.
C. Unscrew the spring retainer and remove the washer from the housing.
D. Remove the spring from the shaft.
E. Slide the desired spring over the shaft.
F. Replace the washer onto the end of the gun housing.
G. Screw the spring retainer into the housing.
H. Screw the stop nut onto the end of the gun shaft.
I. Screw the end cap onto the gun housing.

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MODEL 250C WELD GUN
DISASSEMBLY OF THE WELD GUN
A. Remove handle cover screws (items 28, 29 & 45)
B. Lift off the handle cover (item 38)
C. Remove the nut, washer and cap screw (items 34, 35 & 36) from the welding lead
(item 40)
D. Remove the control wires (items 32 & 33) from the trigger switch (item 37) and
remove the switch from the handle
E. Lift out the welding and control lead assemblies (items 40 & 30), from the handle
F. Loosen the cap screw of the cable clamp assembly (item 39) and slide both wires
out of the clamp
G. Unscrew the end cap (item 1) from the gun housing
H. Unscrew the stop nut (item 15) from the end of the shaft
I. Unscrew the knurled spring retainer (item 17) from the gun housing
J. Remove the washer (item 3)
K. Remove the spring (item 4) from the gun shaft
L. Unscrew the three (3) screws (items 9 & 22) from the housing
M. Remove the collet adaptor assembly and dust boot (items 25 & 12) from the shaft
assembly (item 6)
N. Check to be sure there are no burrs on the end of the gun shaft. If necessary use a
file or emery paper to smooth it off. Slide the face plate (item 10) off of shaft
assembly
O. Slide the shaft assembly (item 6) out of the gun housing, making sure the pigtail
assembly (item 7) feeds through the slot in the housing and handle.
To assemble the gun repeat these operations in the reverse order.