Spot welding technical

Typical spot welding conditions for uncoated low carbon steel sheets of thickness thickness 0.4 mm to 3.0 mm
Single sheet thickness Electrode tip diameter Welding conditions
Medium force, long time conditions High force, short time conditions
Over mm Up to and including mm Force kN Weld time 1) cycles Current kA Force kN Weld time 1) cycles Current kA
0.4 0.6 4 0.9 to 1.1 5 to 7 4 to 6 1.3 to 1.8 4 to 5 5 to 8
0.6 0.8 4 1.2 to 1.3 7 to 10 5 to 7 1.7 to 2 6 to 8 6 to 9
0.8 1.0 5 1.4 to 1.5 9 to 12 6 to 8 1.9 to 2.6 7 to 10 7 to 10
1.0 1.2 5 1.6 to 1.8 11 to 15 7 to 9 2.5 to 3.2 8 to 12 8 to 12
1.2 1.6 6 1.9 to 2.1 14 to 18 8 to 11 3.0 to 4.0 9 to 13 10 to 13
1.6 2.0 7 2.6 to 2.9 18 to 22 9 to 13 3.9 to 5.2 10 to 14 12 to 15
2.0 2.5 8 3.4 to 3.7 22 to 28 10 to 15 5.0 to 6.2 12 to 16 14 to 18
2.5 3.0 9 4.4 to 4.7 28 to 35 12 to 17 6.0 to 7.5 15 to 20 17 to 20
1) 1 cycle = 0.02s

 

 

Typical spot welding conditions for uncoated low carbon steel plates of thickness 3.0 mm to 12.0 mm using a single-phase a.c. machine
Single plate thickness Electrode tip diametermm Welding conditions
Over mm Up to and including mm Force kN Total pulsed weld time s Current kA
3.0 4.0 12 11.5 0.70 20
4.0 5.0 14 15.5 1.40 23
5.0 6.0 17 22.7 2.38 28
6.0 7.0 18 25.5 3.08 30
7.0 8.0 19 28.5 4.34 33
8.0 9.0 21 34.5 5.46 36
9.0 10.0 23 41.5 7.56 38
10 12.0 26 53.0 11.90 43
1) 1 cycle = 0.02s
Note 1. Multiple impulses of 0.1s (5 cycles) on 0.04 s (2 cycles) off, are recommended

Note 2. Total pulsed weld time is (on time plus off) multiplied by number of pulses.

 

Typical spot welding conditions for hot-dip zinc, zinc-5 % aluminium, zinc-55 % aluminium and electrolytically deposited zinc coated steel sheets of combined thickness 0.4 mm to 3.0 mm
Single sheet thickness Electrode tip diameter Welding conditions
Hot-dip zinc, zinc-5 % aluminium, zinc-55 % aluminium (see note 1) Electrolytically deposited zinc (See note 2)
Over mm Up to and including mm Force kN Weld time 1) cycles Current kA Force kN Weld time 1) cycles Current kA
0.4 0.6 4 1.5 to 2.0 6 to 8 7 to 9 1.5 to 2.0 6 to 7 6.5 to 8.5
0.6 0.8 4 1.9 to 2.2 8 to 10 8 to 10 1.9 to 2.2 8 to 10 7.5 to 9.5
0.8 1.0 5 2.2 to 2.9 9 to 12 9 to 11 2.2 to 2.9 9 to 12 8.5 to 10.0
1.0 1.2 5 2.9 to 3.6 10 to 13 10 to 13 2.8 to 3.6 10 to 13 9.5 to 12.5
1.2 1.6 6 3.4 to 4.5 11 to 15 14 to 16 3.4 to 4.5 11 to 15 12.0 to 14.5
1.6 2.0 7 4.4 to 5.5 12 to 16 18.0 to 21.0 4.4 to 5.5 12 to 16 14.0 to 17.0
2.0 2.5 8 5.4 to 6.8 14 to 18 22.0 to 26 5.4 to 6.8 14 to 18 17.0 to 22.0
2.5 3.0 9 6.6 to 8.0 17 to 21 26 to 30.0 6.6 to 8.0 17 to 21 19.0 to 24.0
1) 1 cycle = 0.02s
Note 1. Applicable for coating thickness G275 ( = 20µ m on each surface)
Note 2. Applicable for coating thickness 7.5µ m on each surface.

 

 

Typical spot welding of double sided iron-zinc alloy and zinc-nickel alloy coated steels of sheet thickness 0.4 to 3.0 mm
Single plate thickness Electrode tip diametermm Welding conditions
Over mm Up to and including mm Force kN Weld time1) cycles Current kA
0.4 0.6 4 1.4 to 1.9 4 to 6 6.0 to 8.5
0.6 0.8 4 1.8 to 2.1 6 to 8 7.0 to 9.5
0.8 1.0 5 2.1 to 2.8 7 to 10 8.0 to 10.5
1.0 1.2 5 2.7 to 3.4 8 to 12 9.0 to 12.0
1.2 1.6 6 3.2 to 4.3 9 to 13 11.0 to 14.0
1.6 2.0 7 4.2 to 5.3 10 to 14 13.0 to 16.5
2.0 2.5 8 5.2 to 6.5 12 to 16 16.0 to 21.0
2.5 3.0 9 6.4 to 7.8 15 to 20 18.0 to 23.0
1) 1 cycle = 0.02s
Note. These conditions are applicable to iron-zinc alloy coatings of thickness, for each surface, of between 5µ m to 10 µ m (equal to a coating mass of 35 to 70 g/m) and zinc-nickel coatings of thickness, for each surface, of up to 7µ m (equal to a coating mass of 50g/m²).

 

 

Typical spot welding conditions for two terne coated steel sheets of thickness 0.4 mm to 1.6 mm
Single plate thickness Electrode tip diametermm Welding conditions
Over mm Up to and including mm Force kN Weld time1) cycles Current kA
0.4 0.6 4 1.5 to 2.0 6 to 8 7 to 9
0.6 0.8 4 1.9 to 2.2 8 to 10 8 to 10
0.8 1.0 5 2.1 to 2.9 9 to 12 9 to 11
1.0 1.2 5 2.9 to 3.6 10 to 13 10 to 13
1.2 1.6 6 3.4 to 4.5 11 to 15 14 to 16
1) 1 cycle = 0.02s
Note. These conditions are applicable to terne coated steel of coating mass 150 g/m², including both surfaces

 

 

Typical spot welding conditions for aluminium coated steel sheet of thickness 0.4 mm to 2.0 mm
Single plate thickness Electrode tip diametermm Welding conditions
Over mm Up to and including mm Force kN Weld time 1) cycles Current kA
0.4 0.6 4 1.5 to 2.0 8 to 10 8.5 to 10.0
0.6 0.8 4 1.9 to 2.2 10 to 12 9.0 to 11.0
0.8 1.0 5 2.2 to 2.9 12 to 14 10.0 to 12.0
1.0 1.2 5 2.8 to 3.6 14 to 16 11.5 to 13.0
1.2 1.6 6 3.4 to 4.5 18 to 22 12.0 to 15.0
1.6 2.0 7 4.4 to 5.5 22 to 26 14.5 to 17.5
1) 1 cycle = 0.02s
Note. These conditions are applicable to terne coated steel of coating mass 150 g/m², including both surfaces

 

 

Typical minimum weld strength values (shear to failure) for low carbon steel of 280 N/mm² minimum tensile strength.
Sheet thickness mm Nominal 3.5t weld size Nominal 4√t weld size Nominal 5√t weld size Nominal 6√t weld size
Weld diameter mm Weld strength kN Weld diameter mm Weld strength kN Weld diameter mm Weld strength kN Weld diameter mm Weld strength kN
0.6 2.7 1.3 3.1 1.6 3.9 2.0 4.6 2.3
0.8 3.1 2.3 3.6 3.0 4.5 3.6 5.4 4.2
1.0 3.5 3.2 4.0 3.7 5.0 4.3 6.0 5.1
1.2 3.8 4.1 4.4 4.6 5.5 5.4 6.6 6.2
1.6 4.4 5.5 5.1 6.0 6.3 7.4 7.6 8.3
2.0 5.0 7.2 5.7 8.4 7.1 10.8 8.5 13.0
2.5 5.5 10.6 6.3 11.8 7.9 14.5 9.5 17.3
3.0 6.1 12.0 6.9 14.0 8.66 17.8 10.4 22.0