How do you calculate good brazed core output per shift?

Multiply cores per cycle by cycles per shift for gross capacity, then multiply by uptime and post-braze yield. With 4 cores x 24 cycles = 96 gross, times 90% uptime and 97% yield, you get 83.8 good cores per shift.

What is gross furnace capacity versus good output?

Gross capacity is the theoretical maximum — 96 cores/shift here — assuming no downtime and zero rejects. Good output, 83.8 cores/shift, is what survives 90% uptime and 97% braze yield and is the number you should commit to.

How much output does furnace downtime cost?

In the example, 10% downtime removes 9.6 cores per shift from the gross 96. On an expensive braze furnace that lost capacity is rarely recoverable elsewhere, which is why uptime is usually the highest-leverage improvement.

What is a good post-braze first-pass yield for cores?

Well-controlled CAB or vacuum aluminum brazing often runs 96-99% first-pass; new fluxing, fixture or atmosphere problems can drop it into the low 90s. The 97% default is healthy — every point below that is leak-test rejects and rework.

How do I increase brazed core output without buying a furnace?

Three levers: load more cores per cycle if the fixture and atmosphere allow, recover cycles by cutting changeover and downtime, or lift first-pass yield. Here, raising uptime from 90 to 95% alone recovers about 4.7 cores per shift.

Why multiply uptime and yield instead of subtracting them?

They are sequential losses on different bases: uptime cuts the gross capacity, then yield cuts what was actually brazed. Multiplying applies each to the surviving quantity, which is why the downtime loss (9.6) and reject loss (2.6) do not simply add to a flat percentage of 96.

Heat Exchanger, Coil & Radiator Manufacturing calculator

Brazing Furnace Load Calculator

Brazing furnace load is the count of good, leak-tight cores a brazing line actually delivers per shift after furnace downtime and post-braze rejects are taken out. Production supervisors and capacity planners use it to size daily output, commit to a build schedule, and find whether the furnace, the load count or the braze quality is the real bottleneck. A controlled-atmosphere or vacuum braze furnace is usually the most expensive and least flexible asset on a coil line, so every point of uptime or first-pass yield translates straight into shippable cores. This calculator turns load, cycle, uptime and yield into a number you can actually promise.

What this calculator does

Estimate good brazed core output per shift from fixture load, furnace cycles, uptime, and post-braze yield.
Use it when a controlled atmosphere brazing furnace, vacuum brazing furnace, or batch braze oven is the constraint for radiator, charge air cooler, condenser, or evaporator production.
It computes good brazed cores per shift by taking the gross furnace capacity and applying furnace uptime and post-braze first-pass yield.

Formula used

Gross brazed core capacity = cores loaded per cycle × usable furnace cycles
Good brazed core output = gross capacity × furnace uptime × post-braze yield

Inputs explained

Cores loaded per furnace cycle:
Usable furnace cycles per shift:
Furnace availability/uptime:
Post-braze first-pass yield:

How to use the result

Use it for shift capacity planning, scheduling a braze line, or quantifying how downtime or braze rejects cut into shippable output.
It models a single furnace at steady state and uses average uptime and yield — it does not capture cycle-time variation, load-mix changes or rework that is later recovered.

Current U.S. benchmarks

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).

Common questions

How do you calculate good brazed core output per shift? Multiply cores per cycle by cycles per shift for gross capacity, then multiply by uptime and post-braze yield. With 4 cores x 24 cycles = 96 gross, times 90% uptime and 97% yield, you get 83.8 good cores per shift.
What is gross furnace capacity versus good output? Gross capacity is the theoretical maximum — 96 cores/shift here — assuming no downtime and zero rejects. Good output, 83.8 cores/shift, is what survives 90% uptime and 97% braze yield and is the number you should commit to.
How much output does furnace downtime cost? In the example, 10% downtime removes 9.6 cores per shift from the gross 96. On an expensive braze furnace that lost capacity is rarely recoverable elsewhere, which is why uptime is usually the highest-leverage improvement.
What is a good post-braze first-pass yield for cores? Well-controlled CAB or vacuum aluminum brazing often runs 96-99% first-pass; new fluxing, fixture or atmosphere problems can drop it into the low 90s. The 97% default is healthy — every point below that is leak-test rejects and rework.
How do I increase brazed core output without buying a furnace? Three levers: load more cores per cycle if the fixture and atmosphere allow, recover cycles by cutting changeover and downtime, or lift first-pass yield. Here, raising uptime from 90 to 95% alone recovers about 4.7 cores per shift.

Last reviewed 2026-05-12.