Since this is a question please use a different forum section next time.
The category "Translation & Bug Report" is not meant for question.
For your question: Which enchantment chip is being used doesn't always depend on the Grade of Weapon/Armor.
For grade 34 there are weapons that use Enchantment Chip Veteran while some others use Enchantment Chip Expert.
You will have to tell me which weapon or weapon series we talking in particular please