Hi there ps3081.
I have a Castolin booklet in my hand(British Version)
and this is what is said about the 690 electrode:-
High strength metal arc electrode for the joining and o
verlaying special steel parts.
Provides a combination of both strength and ductility for the welding of components susceptible to hardening such as
high carbon steels,air hardening steels,die steels,low alloy steels and martensitic stainless steels
PROPERTIES.
Tensile Strength: 700-740N/mm2.
Elongation: 35-40%
A highly alloyed electrode producing deposits resistant to
cracking, but in particular offering good ductility which is especially important on highly streesed components.
The 690 's an ideal choice for the joining of dissimilar
high strength steels including alloy steel to 12-14% austenitic manganese steels.In many cases where components
require hard overlays buttering with 690 is recommended,as
deposits are tolerant to dilution effects and are compatible
with both base materials and hard overlay deposits.
Deposits exhibit good weld bead shape and smooth appearance
and slag is readily detached.Designed for use in flat and
vertical up positions.For use with both AC and DC power source.
Dia.mm 2.4 3.2 4.o 5.0
AMPS 40-70 60-100 80-130 130-180.
Hope this helps you,
Best of Luck-TWWeld.