Primitive Blast Furnace & Steel Tutorial – Gregtech CEu Modern

In the steamage progression of Gregtech CEu Modern, the primitive blast furnace is one of your essential crafting stations. This tutorial will walk you through crafting and operating a primitive blast furnace to produce steel ingots and unlock stronger tools and high-pressure machines.

Crafting the Primitive Blast Furnace

Required Materials

To build a primitive blast furnace, you’ll need fire bricks as your primary material. Fire bricks are crafted by heating compressed fire clay. Here’s the breakdown:

Fire Clay Dust — made from clay and brick dust combined

Compressed Fire Clay — created by heating fire clay dust

Fire Bricks — produced by heating the compressed fire clay

Crafting Tools You’ll Need

You’ll also need an iron or bronze mortar to crush materials. To craft a mortar, combine 2 ingots (iron or bronze) with stone. This tool allows you to crush clay and bricks together to produce fire clay dust.

Building the Structure

The primitive blast furnace is constructed in a 3×3×4 hollow structure:

Dimensions: 3 blocks wide × 3 blocks deep × 4 blocks tall

Construction: Fill all exterior walls with fire bricks

Interior: Leave completely empty

Top: Leave one hole open for item input

Once constructed, place the Primitive Blast Furnace block into one of the remaining holes. You’ll see a “Structured Out Formed” message at the top of your screen, confirming the structure is valid.

Operating the Primitive Blast Furnace

Fueling the Furnace

Insert coal or blocks of coal into the bottom of the furnace. This serves as fuel to power the smelting process.

Smelting Steel Ingots

To produce steel ingots, you’ll need:

Coal (bottom input — acts as fuel)

Iron (top two inputs — the recipe materials)

Place coal at the bottom and iron in the top two slots. The furnace will then slowly process these materials into steel ingots. As a bonus byproduct, you’ll also receive tiny piles of dark ashes, which can be converted into regular dark ash for other crafting recipes.

What You Can Make With Steel

Steel ingots unlock several important crafting recipes:

Stronger tools — improved durability and efficiency

High-pressure machines — more advanced Gregtech equipment

High-Pressure Steam Boilers

One key upgrade available with steel is the High Pressure Steam Solid Boiler:

High Pressure Boiler Output: 15 millibuckets per tick of steam

Low Pressure Boiler Output: 6 millibuckets per tick of steam

The high-pressure version produces over double the steam output compared to low-pressure boilers, making it significantly more efficient. Whether you upgrade immediately or wait until you reach low voltage progression is entirely up to your playstyle.

Conclusion

The primitive blast furnace is a straightforward but powerful addition to your Gregtech CEu Modern base. Once you’ve constructed it and begun producing steel, you’ll unlock access to stronger tools and high-pressure machines that will accelerate your progression through the mod’s technology tiers. Now that you know how to build and operate it, you’re ready to start your journey into the steamage!

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