The following are some information about billets:
About product name, the actual name is billet, but on contract should be steel square bar or equivalent.
Because square bar has 13% tax refund, billet need to pay 25% export tariff, the difference is 38%, the actual calculating method is more complicated but the result is not far.
So the price is cheap because it is using products need to pay 25% to get 13% back.
Alloy, only alloyed square has tax refund, before 2015, the alloy is Boron, but this alloy has been eased from list, so from this year, we use Chromium(Cr), content is 0.3% and above, and the Cr is good for strength.
About the certificate of origin (CO), as said above the export name is not actually the real name, so the application of the CO of the products is more complicated, if the CO is not necessary, it is better not to apply, but if it is necessary, we can get the CO.
Some south Asian countries do not allow Chinese "square" to be import, only allow "billet", so please confirm if Laos has similar policy.