Crafting 9 copper ingots together in a crafting table or Extra Utilities mechanical crafter results in a Mekanism copper block, It should result in a Thermal Foundation copper block. Tin is the same.
Update: This goes for converting ingots to nuggets as well!

As I figure them out:

1. copper
2. tin
3. bronze
4. charcoal - turns into a chisel (raw) charcoal block which does not burn. should be a Forestry or Mekanism charcoal block. This sucks because there's a lot of automation with tree farm -> charcoal blocks
   • This seems to only happen with the Extra Utils 2 mechanical and analog crafters. Crafting table results in a Mekanism block, which is okay.
   • Cyclic Auto Crafter properly converts charcoal to a Mekanism charcoal block, so you can tell players to use that instead of the Extra Utils 2 machines. Downside: the auto crafter needs power, whereas the EU2 machines don't.

Edit: Took out osmium - it is mekanism only, so there is no Thermal variant of the ore.

Update (180112): I've tried a lot of other ores and the list above is, so far, the only ones I've found with the block crafting problem.

This might be resolved by a new crafttweaker script I'm working on to help forcibly unify blocks <-> ingots <-> nuggets

This is a very useful report as it gives me specific targets to check for compliance, thank you!

Bronze has been addressed specifically for 5.7 but this is an ongoing area of improvement I'm still working on

Copper still doing this as of 5.9.3b
Possible fix for in-progress games is to use the Forge Lexicon, and select the wanted block/ingot type.