DIN 8556

 

E 20 25 5 Cu L R 2 3 -
1 2 3 4 5 6

 
 
 

1 Short symbol for manual arc welding

 
 

2 Short name for chemical structure of the weld metal. The alloy components (approximate values) are listed in the order Cr, Ni, Mo numerically one after another without their chemical symbols. Alloy components like niob and copper are added as their chemical symbol without specification of their contents. Mangan as alloy component is listed as chemical symbol only if its content exceeds 5 % of the total weight. The addition L indicates a very low carbon content.

 
 

3 Short symbol Type of coating
R Rutile type
These rod electrodes contain titanium oxide as main component in their coating, mostly in rutile form.
B Basic type
The coating contains a high proportion of calcium or other alkaline earth metal carbonates and fluorspar.
MP Alloy-coating type
Alloy-coating high-performance electrodes need to be marked with the short symbol MP for metal powder before the short symbol for coating type, e. g. MP R.

 
 

4 Code no. Code letter acc. to DIN 1912 Welding position
1 w, h, hü, s, f, q, ü

all positions

2 w, h, hü, s, q, ü
w

all positions, except vertical-down position

butt weld, flat position

3 w
h
fillet weld, flat position
fillet weld, downhand position
4 w
w

butt weld, flat position

fillet weld, flat position

 
 

5 Code no. or symbol for current suitability
AC or DC DC only
Open-circuit voltage
at (V)
Code no. Polarity of the rod electrode
50 1 4 7 0 any polarity
70 2 5 8 0- negative
90 3 6 9 0+ positive

 
 

6 Code no. Transfer efficiency
- <105%
110  105% < 115%
120  115% < 125%
130  125% < 135%
140  135% < 145%
150  145% < 155%
160  155% < 165%