How do you calculate sintering energy cost for rare earth magnets?

Multiply furnace-hours by the power rate, then by the on-load duty percentage, and add the fixed vacuum and chiller base load. With 120 furnace-hours at $38/hr, 80% duty and a $600 base load, total energy cost is $4,248.

Why include an on-load duty percentage?

A sinter cycle spends hours at full ramp and soak power but idles at lower draw during slow cooling and hold. The 80% duty factor scales the connected load down to the realistic average, so you do not overstate energy by assuming full power the whole run.

What is the per-unit energy cost in the default example?

Dividing the $4,248 total by the run gives $35.40 per piece of energy cost. That figure lets you compare furnaces and lot sizes on a like-for-like basis.

How much of the cost is fixed versus variable?

In the default run the variable furnace draw is $3,648 and the fixed vacuum/chiller adder is $600. Small lots carry that same $600 fixed cost, which is why short runs cost far more per magnet.

Does this include demand charges or power factor penalties?

No. It models energy (kWh-equivalent) cost only. If your utility bills peak demand (kW) or power-factor penalties, add those separately, because a large sinter furnace can spike your monthly demand tier.

How can I lower sintering energy cost per magnet?

Fill the furnace: running fuller loads spreads the fixed base load and the fixed portion of the cycle over more pieces. Consolidating two half loads into one full run typically cuts per-piece energy more than shaving the electricity rate.

Rare Earth Magnet & Motor Materials calculator

Energy Cost Calculator

Vacuum sintering and annealing are the single largest energy draws in NdFeB and SmCo magnet production, often dwarfing raw-material electricity once duty cycles and chiller loads are counted properly. This calculator estimates the true energy cost of a sinter run by combining metered furnace-hours, an electricity rate, the fraction of the cycle spent at full power draw, and the standing base load from vacuum pumps and water chillers. Process engineers, cost estimators and plant controllers use it to attribute energy correctly to a magnet lot instead of smearing it across all output. Because rare earth sintering runs long soak and slow-cool ramps, getting the on-load duty right is the difference between a defensible quote and a money-losing one.

What this calculator does

Estimate the electricity and utility cost of sintering, annealing and magnetizing rare earth magnet and motor materials.
A plant manager prices the power draw of a vacuum sinter campaign to size it into the magnet quote.
It computes total furnace energy cost for a sinter run and splits it into variable draw plus fixed vacuum/chiller base load, then divides to a per-piece energy cost.

Formula used

Total energy = furnace-hours x power rate x on-load duty + base load
Per-hour energy cost = total energy / furnace-hours

Inputs explained

Sintering furnace runtime:
Electricity rate:
On-load duty:
Vacuum and chiller base load:

How to use the result

Use it when costing a sintering or heat-treat batch, benchmarking furnaces, or deciding whether to consolidate small lots into fewer long runs.
It treats on-load duty as a single average percentage, so furnaces with sharply peaked ramp-up draw or utility demand charges will read differently than this linear model.

Current U.S. benchmarks

As of Apr 2026, industrial electricity averages 8.7 cents per kWh across the U.S. (EIA), up 5.5% from a year earlier. State averages range widely, so plants should confirm against their own tariff.
The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).
The U.S. has 5,397 electrical equipment and appliances establishments employing about 369,437 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate sintering energy cost for rare earth magnets? Multiply furnace-hours by the power rate, then by the on-load duty percentage, and add the fixed vacuum and chiller base load. With 120 furnace-hours at $38/hr, 80% duty and a $600 base load, total energy cost is $4,248.
Why include an on-load duty percentage? A sinter cycle spends hours at full ramp and soak power but idles at lower draw during slow cooling and hold. The 80% duty factor scales the connected load down to the realistic average, so you do not overstate energy by assuming full power the whole run.
What is the per-unit energy cost in the default example? Dividing the $4,248 total by the run gives $35.40 per piece of energy cost. That figure lets you compare furnaces and lot sizes on a like-for-like basis.
How much of the cost is fixed versus variable? In the default run the variable furnace draw is $3,648 and the fixed vacuum/chiller adder is $600. Small lots carry that same $600 fixed cost, which is why short runs cost far more per magnet.
Does this include demand charges or power factor penalties? No. It models energy (kWh-equivalent) cost only. If your utility bills peak demand (kW) or power-factor penalties, add those separately, because a large sinter furnace can spike your monthly demand tier.

Last reviewed 2026-05-12.