Minecraft.getMinecraft().getRenderItem().getItemModelMesher().register(SteelSword, 8000, new ModelResourceLocation("swm:item_SteelSword", "inventory"));
should be changed to
Minecraft.getMinecraft().getRenderItem().getItemModelMesher().register(SteelSword, 0, new ModelResourceLocation("swm:SteelSword", "inventory"));
Also, never capitalize the first letter of variables. Always capitalize the first letter of classes, though.