Stardew Valley Heavy Furnace

Mining Mastery, 25 ore batches, Coal savings, Quartz refining, and Skull Cavern bars

Stardew Valley Heavy Furnace Guide

Heavy Furnace turns Mining Mastery into a real production upgrade. Batch 25 ore with 3 Coal for 5-6 bars, use Quartz and Fire Quartz for Refined Quartz bursts, and build a furnace lane that supports Skull Cavern, Radioactive Ore, and late-game crafting without drowning the farm in single-bar chores.

25

ore per batch

3

Coal per run

5-6

bars output

The recipe unlocks from Mining Mastery and uses 2 Furnaces, 3 Iron Bars, and 50 Stone.

Ore batches consume 25 ore and 3 Coal, then output either 5 or 6 bars.

Average savings are about 9% ore and 45% Coal compared with ordinary Furnaces.

Heavy Furnace route modules

6 guides

Unlock / Mining Mastery, 2 Furnaces, 3 Iron Bars, and 50 Stone

Heavy Furnace Unlock and Crafting

重型熔炉解锁与制作

Heavy Furnace unlocks from Mining Mastery and is crafted with 2 Furnaces, 3 Iron Bars, and 50 Stone. Build it once the save has enough ore flow to process full 25-ore batches instead of one bar at a time.

Mechanics / 25 ore, 3 Coal, and 5-6 bars

25 Ore Batch Smelting Rules

25 个矿石批量冶炼规则

For ore, Heavy Furnace consumes 25 ore and 3 Coal per run. Each batch has an equal chance to output 5 or 6 bars, so the average batch beats five ordinary furnace runs on both ore and Coal.

Efficiency / Average 9% ore savings and 45% Coal savings

Ore and Coal Economy

矿石与煤炭经济

Compared with ordinary Furnaces, Heavy Furnace saves about 9% ore and 45% Coal on average when smelting bars. That makes it strongest for Iridium, Radioactive, and other high-volume mining routes.

Refining / 5 Quartz or 5 Fire Quartz plus 3 Coal

Quartz and Fire Quartz Refining

石英与火水晶精炼

Heavy Furnace can also run 5 Quartz or 5 Fire Quartz with 3 Coal. Quartz yields 5-6 Refined Quartz, while Fire Quartz yields 15-20 Refined Quartz for sprinkler, crystal path, and crafting stockpiles.

Layout / Ore chest, Coal chest, regular Furnaces, and Heavy Furnace lanes

Furnace Lane Layout and Throughput

熔炉动线与吞吐

The cleanest layout keeps Heavy Furnaces beside ore and Coal chests, with ordinary Furnaces beside them for leftover stacks. This makes morning pickup, late-night dump, and shed-based bar production easier to repeat.

Late Game / Iridium, Radioactive Ore, Mining Mastery, and Dwarf King powers

Skull Cavern and Radioactive Ore Planning

头骨山洞与放射性矿规划

Heavy Furnace turns deep mining days into efficient bar production. Use it after Skull Cavern Iridium dives, dangerous mine Radioactive Ore weeks, and Dwarf King ore or coal power days to compress late-game crafting costs.

Batch inputs

25 + 3 Coal

Copper Ore

5-6 Copper Bars

Bulk process early ore for tappers, machines, and basic crafting once batches are available.

25 + 3 Coal

Iron Ore

5-6 Iron Bars

Excellent for kegs, quality sprinklers, tappers, bee houses, and machine-heavy farms.

25 + 3 Coal

Gold Ore

5-6 Gold Bars

Use for tool upgrades, quality sprinklers, crystalariums, and mid-game crafting pressure.

25 + 3 Coal

Iridium Ore

5-6 Iridium Bars

The premium batch target after Skull Cavern dives because every saved ore and Coal matters.

25 + 3 Coal

Radioactive Ore

5-6 Radioactive Bars

Plan around dangerous mine weeks and Qi routes, then batch before late-game recipes need bars.

5 + 3 Coal

Quartz

5-6 Refined Quartz

Steady Refined Quartz source for sprinklers, Lightning Rods, crystal paths, and crafting cleanup.

5 + 3 Coal

Fire Quartz

15-20 Refined Quartz

High-output Refined Quartz burst; save it when the farm needs a large crafting stockpile.

Layout patterns

Ore chest lane

Place Copper, Iron, Gold, Iridium, Radioactive Ore, Quartz, and Coal chests beside Heavy Furnaces for fast batch starts.

Mixed furnace line

Keep ordinary Furnaces beside Heavy Furnaces so under-25 leftovers can still become bars.

Skull Cavern dump chest

Use a labeled chest near the farm return point for Iridium Ore, Omni Geodes, coal, bombs, and staircases.

Volcano and island bin

Separate Cinder Shards, Dragon Teeth, Fire Quartz, and island loot from normal mine ore to reduce sorting drag.

Late-game shed

Move heavy refining into a shed once outdoor machine lanes compete with barns, crops, and artisan layouts.

Heavy Furnace planning loop

Step 1

Claim Mining Mastery.

Step 2

Craft with ordinary Furnaces, Iron Bars, and Stone.

Step 3

Sort full 25-ore batches beside Coal.

Step 4

Run leftovers through regular Furnaces.