Method 1: Crafting Table
Place 3 Red Nether Bricks in a Crafting Table to make 6 Red Nether Brick Slabs.
6 How to Make a Red Nether Brick Slab in Minecraft
Use this simple recipe to make a Red Nether Brick Slab in Minecraft. You can see the exact ingredients, recipe layout, and workstation below.
Red Nether Brick Slab recipe
Follow the recipe below. The pattern must use the correct slots when the recipe is shaped.
6 
Method 2: Stonecutter
Use 1 Red Nether Bricks in a Stonecutter to make 2 Red Nether Brick Slabs.
2 About this Minecraft recipe
This page shows the vanilla recipe for Red Nether Brick Slab. It includes the exact ingredients, recipe layout, required workstation, and amount produced.
The data comes from Minecraft Java 26.2. Recipes can change in later game versions, so check the version you play before crafting.