Very sorry for my late,1st to 7th Oct is our public holiday.
I've checked with our production manager,the black is oxide after anneal,usually all the export goods will do polish and sand-blast after anneal,but our production manager was in vacation for wedding when we are producing your material,our worker don't realise that this material needs polish and sand-blast,they just do pickling so the surface is not so good.
As 347H material is very hard,so there will be very very little small cracks,I've checked with our engineers,this won't influce the physical properties and use.
I'm sorry about it,the products I sent to you is not so good this time,if the materials are still in our factory,I'll do everything I can to fix it. But now they are in Thailand. Our factory director is angry about it,this is our mistake.
Did you use the materials? Will it have big influce for use?
I promise this will never happen again in future.
If you still have demands nect time,I will send all the photos of the surface and other details to you.
If you have any question please let me know,thank you.
Best Regards,