The material for that are mainly the Q235B (S235Jr the yield strength is more than 235Mpa) and Q345B (S355Jr the yield strength is more than the 345Mpa).
The guardrail is mainly to follow the AASHTO M180, GB-T 31439.1-2015 and EN1317 standard.
For the thickness of the guardrail mainly through the 4.0mm to 7.0mm or follow the customers demand.
The post is mainly to follow the AASHTO M180, GB-T 31439.1-2015 and EN1317 standard.