Hi nathan! , I dont really know if this site is to ask to you about your post about "custom models".
https://www.spigotmc.org/wiki/custom-item-models-in-1-9-and-up/
I followed all your steps and i have a problem more or less, I was able to add custom models but i cant get that models with /mgive <Player> diamond_spade:1 command of Magic.. I can get that models with the minecraft comamnd "/give <player> minecraft:diamond_shovel 1 1 {Unbreakable:1}" , Do you know what could be the problem??

I have this in my json model
{
	"parent": "item/handheld",
	"textures": {
		"layer0": "item/diamond_shovel"
	},
	"overrides": [
		{ "predicate": {"damaged": 0, "damage": 0}, "model": "item/diamond_shovel"},
		{ "predicate": {"damaged": 0, "damage": 0.0006402048655569782}, "model": "item/custom/test_test"},
		{ "predicate": {"damaged": 1, "damage": 0}, "model": "item/diamond_shovel"}
	]
}

The way the JSON is set up the custom models only appear on unbreakable items. The /mgive command just gives you a regular item. You can use /mitem add unbreakableto make the item unbrekable.

Um, works perfectly , thank you so much :D

Is just a question but, is possible to change the durability of the armor and change that models?

No, unfortunately.

Oh :(

A little thing more , Im sorry ahahah , How can i put that custom models with the hat trait?
Im trying to use /mtrait hat diamond_spade:1 But appear the regular item with the pink and black texture :S

You would need to make it an unbreakable item, save it with a name, then use that item. Like

/mgive diamond_spade:1
/mitem add unbreakable
/mitem save mything
/mtrait hat mything

Thank you so much ^^