We offer that the stud welding system to the inspection machine to development, manufacture and sales by in-house consistent system.

Technological material and Q&A

CD method stud welding system

The CD (capacitor discharge) system is a momentary stud welding system having a welding time on the order of 1/1000 second and using energy accumulated by the capacitor group with original design and performance. Because of extremely low ark heat/merge, distortion, tranceformation, etc. of the back of the base material hardly occur. The system is suitable for welding a lamina or a delicate surface-treated base material, and has features impossible in other welding methods.

The welding cycle operates automatically and a uniform stud welding is completed only by pulling the trigger switch after the stud is inserted in the collet chuck of the welding gun and pressed to the base material.

This is a semi-automatic welding system operated by anybody because special qualification is not required.

Stud welding machine basis composition connection chart

Stud welding machine basis composition connection chart

Method of welding stud

AGFasteners According to a stud material to be welded etc., the CD stud welding system allows selection of [contactiong method]and [gap method] only by exchange of guns.

Contactiong method Gap method
Suited gun:A-50・A-100・A-200 Suited gun:A-300
Contactiong method

Stud is pressed to base material in advance, and welding are carried out. The method is suitable for welding of mild steel, stainless steel, brass, and copper.

Gap method

Welding cycle is started with distance between stud and base material. Stud is quickly brought into contact with base material, and electrical discharge and welding are carried out. The method is suitable for welding of aluminium and titanium, and effective for welding of minute diameter stud made of mild steel and stainless steel.

Stud and welding acceptable table of mother material

One of the features of the CD method stud welding is a thing in the base material the same kind or the different kind material that can be welded as for the stud of various materials. Especially, the stud of the aluminium titanium assumed to be an extremely difficult so far can be welded by an easy.

Base Material stud
Mild Steel Stainless steel Brass opper Aluminium Titanium
Rolled steels for general structure SS × ×
Cold-rolled steel materials SPC × ×
Carbon steel material for machine structure ~S20C   × ×
Galvanized iron sheet   × ×
Stainless steel plate SUS 302 × ×
SUS 304 × ×
SUS 403 × ×
Brass(There is no lead content)   × ×
Aluminium No.1000 × × × × ×
No.5000 × × × × ×
No.3000 × × × × ×
No.6000 × × × × ×
Two kinds of pure titanium   × × × × ×
注)weldability: ◎excellent、○good、△abjustment required、×rejected
the above is rough welding suitability of stud and base material.Please confirm actual suitability of the welding beforehand.

 Welding strength of CD stud

The stud properly welded can support a purpose of use as fastening that have strength suitable for the diameter and materials.

Material Stud dia Pull strengt
Shearing strength
Twist strength
Base Material Stud
Mild steel Mild steel M3 215 125 13
M4 380 225 35
M5 605 355 60
M6 870 510 113
M8 1,465 865 250
M10 2,375 1,425 493
M12 3,455 2,075 805
Stainless Steel Stainless Steel M3 325 200 22
M4 580 355 46
M5 955 580 90
M6 1,380 825 165
M8 2,400 1,500 380
M10 3,500 2,355 805
Aluminium Aluminium(No.1000) M3 60 32 4
M4 110 60 9
M5 175 99 20
M6 240 135 28
M8 440 250 65

In an actual design, please consider the safety if necessary.

Positioning of stud

It is a method of Pontinging to the welding position on the mother material side as the most general positioning method and matching the chip (projection) in the stud point.

Positioning of stud
I recommend the stud bolt welding robot ASR series to more correct stud bolt positioning.

Stud (dia) Punch hole size(mm)
M3 ~0.7 ~0.35
M4 ~0.8 ~0.40
M5 ~0.9 ~0.45
M6 ~1.0 ~0.50
M8 ~1.2 ~0.60
M10 ~1.4 ~0.70
M12 ~1.8 ~0.90

A too large punch hole causes the poor weld.



  • The professional skill is required for the repair of our equipment and contact our company or our agency, please.
  • The change of remodeling and parts by the customer might not cause an unexpected accident, and never do, please. Moreover, it doesn't use it excluding an original usage.
  • Please never use it in the place of the fire strict prohibition. Moreover, please use it after confirming there is no combustible in the surrounding. It causes a fire and the explosion.
  • Using it must use the eye shield and the leather glove, etc.
  • Please cut the power on/off switch without fail, and pull out the plug of the power cable from the outlet when it doesn't use, and internal is checked and you clean it.
  • Please do not touch the welding machine with a wet hand and damp clothes worn to the body.
  • Please set it up horizontally in a place firm so that there is no possibility of the fall and the fall when you set up the welding machine.
  • Please use the power-supply voltage by the ratings value of a prescribed each equipment. A fire and the possibility of the electric shock break out by generation of heat when the ratings value is exceeded.
Please make sure the manual of the attachment in detail additionally about each equipment.    

Stud welding Q&A

First of all, please confirm the symptom when thinking the breakdown.

1The power supply doesn't enter.
Check point
  • 1.Is the power cable normally connected?
  • 2.Is not the overcurrent protection circuit protector intercepted?
  • 1.Please connect the power cable normally.
  • 2.Please turn on the circuit protector.
  • 3.Please request the repair to us or the sales agent when damaging it.
2Even if the gun switch is pushed, the welding start is not done.
Check point
  • 1.Is the earth correctly clamped to the mother material?
  • 2.Are the gun cable and the control cable correctly connected?
    Or, Is it not breakdown?
  • 3.Are there neither painting nor an insulation film in the mother material? (alumite treatment in case of aluminum)
  • 1.Please clamp the earth to the mother material surely by two places.
  • 2.Please request the repair to us or the shop when damaging it.
  • 3.The welding start is not done because it doesn't energize when there is an insulation film in the surface of the mother material.
    Please remove the film and the welding part where the earth is clamped and remove the film with the grinder etc.
3The welding start is done though the gun switch is not pushed.
Check point
  • 1.Do not you work at the same time by taking the earth of other welding machines such as Tig on the same mother material and a surface plate?
    Or, are not other welding work done in the vicinity?
  • 2.Will you have entered in the main body by iron filings etc.
  • 3.Does the switch of the stud welding gun move normally?
    Or, electricity always passes?
  • 1.It is likely to operate abnormally, and to break down because of the noise of another welding machine.
       There is a possibility that the noise outside the measures range influences though our stud welding machine is doing the noise measures.
    When taking the earth of another welding machine in the same mother material or the same surface plate is used together and the welding work is done, we will recommend the single use.
    Moreover, please take the distance when you do the welding work the other in the vicinity.
  • 2.Please regularly remove the cover of the welding machine after completely intercepting the main power supply, and clean it by the air blow. It causes abnormal operation to be caused by contact to electronic parts iron filings etc.
  • 3.Please clean it, and the foreign body that conducts electricity to surroundings of the gun switch as removing etc.
      Please request the repair to us or the sales agent,when electricity always goes.
4The welded stud comes off.
Check point
  • 1.Is voltage setting propriety that responded to the stud?
  • 2.Is pressuring setting of welding gun propriety?
  • 3.Does not anything (rust, oil, and dry ink, etc.) adhere to the welding position?
  • 4.Are the punch hole diameter and depth not uneven and proper sizes?
  • 5.Have you completely removed it by abrasive when there is a surface film on the mother material?
  • 6.Do you know the opposite pole connection method?
  • 7.Is not Collet damaging by a fire?
  • 8.Is the position where the earth is clamped proper?
  • 9.Do you use genuine external thread/ internal thread stud?
  • 10.Is the movement of the welding gun and the shaft smooth?
  • 11.Are there the spatter,iron fillings, etc at the welding position?
1.Please set a proper voltage.
It becomes an energy scarcity when the voltage setting is low and it becomes an imperfect welding.
When the voltage is low, the space can be done in the weld of the stud.
Surroundings in the weld come to melt excessively when the voltage setting is too high.
When welding by a proper voltage.
The space is not found in the weld and it becomes a moderate, uniform molten state.
When coming off, when strength is confirmed even in the welding by a proper voltage, the pressurizing adjustment of the welding gun is needed.
2.It is a quality judgment standard of the welding gun and the pressurizing setting.
It seems that stud coming off respect shines like the mirror in case of pressurizing is not enough.
Besides, it is seen when there is a lot of impurities in the mother material and no movement of the gun shaft smoothly.
When judging that it is not a proper pressurizing.
The gun back cap is turned right, it becomes a more pressurizing. Please confirm a proper pressurizing after welding every about one rotation, and confirming strength.
The cap in the back of gun is removed, and an inside adjustment screw is turned right, it becomes a more pressurizing. Similarly, please confirm a proper pressurizing after welding every about one rotation, and confirming strength.
Please refer to the manual for details.
3. Please remove rust, oil, and the dry ink, etc. at the welding position.
Please remove dust,oil,rust,dry film of spatter preventopn liquid and marking by dry ink.
Spatter prevention liquid is possible to voltage and pressuring adjustment and welding before dry.
4.The punch hole diameter and depth must observe it after referring to the above-mentioned size table.
When the punch hole diameter and the depth of each position change, the welding becomes not uniform.
5.Please remove painting on the surface of the mother material.
Please grind with grinders etc. flatly a little more greatly than welded the bolt diameters.
About # 80-#240 of the grinding material grain degree is preferable.
6.The connection opposite to usually is effective for the welding to Zn sheet etc.

The connection opposite to the connection of a usual gun/earth is called the opposite pole connection method. The plus and the minus of the stud arc welding that is direct current become opposite, and it is effective to the welding to Zn sheet that should melt the mother material side more.

It is a normal connection that connect welding gun and earth as shown the indication on the main body.
Iron (acid wash, polish, and black thin film) and SUS304 and aluminum and the others.

It is the opposite pole connection method to connect the earth in gun of the main body and to connect the welding gun with earth. (Usual opposite connection of welding gun and earth.)

Iron (Zn sheet) and others(with thin film).

7.Please exchange to the bland-new collet.
Collet's clutches weaken gradually when the welding is repeated.
Please tighten with pliers etc, toward collet's center at that time.
The stud outer welded might be damaged by a fire if it welds with the inside of collet damaged by a fire, and it become the screw damage and a poor weld.
Please exchange it promptly.
8.Please clamp the earth to the corner of the mother material basically.
When the stud is welded, a strong magnetic field is generated in surroundings of the cable where the welding electricurrent. The influence of this magnetic field is received when a small mother material is welded, and the phenomenon that the molten metal is pulled to one direction happens.
In that case, the above-mentioned basic connected chart is referred to, and the earth position recommends the thing clamped to the diagonally of the mother material, because it might become a poor weld.
9.Please use the stud(external thread/internal thread) of genuine.
The stud is one of the important system configurations in the welding result.
Please use the stud must use our company's stud and genuine that can keep the welding result.
10.Please request maintenance or the repair when you can't operate the welding gun shaft in smoothness.
Please move by the hand before it works, and confirm whether there is caught.
We recommend the repair request to be done immediately because a proper pressurizing is not given to the stud, and it becomes a poor weld when movement is bad.
11.Please clean the mother material welding side by the air blow etc.
If there ara spatter and iron fillings at welding part,the electric resistance value is set by chip in point of stud changes extremely, and it becomes an excessive welding and a result imperfect welding.