How do you calculate wire breakage loss?

Divide the number of breaks by the total lengths or coils drawn. With 8 breaks across 250 lengths, the break rate is 8 / 250 = 3.2%.

What is a good breakage rate in wire drawing?

It depends on gauge and material, but fine ferrous wire lines often target well under 1% break-per-coil. A 3.2% rate like the example signals a process worth investigating before it eats yield.

What does the gap-to-target number mean here?

The tool compares your target rate (95% in the default) against the calculated 3.2% break rate, giving a 91.8-point gap. Read it as how far the measured figure sits from your reference, then decide which direction your target is defined in.

What causes wire to break during drawing?

Common culprits are non-metallic inclusions in the rod, worn or wrongly-sized dies, insufficient or degraded lubricant, excessive reduction per pass, and off-temperature material. A rising break rate usually points to one of these.

Should I count every break or only breaks that scrap material?

Be consistent. Most shops count every web break because each one costs line speed and threading time, but if you only care about scrap you can count scrapping breaks instead — just don't switch definitions between shifts.

How does break rate relate to spool capacity?

Breaks drive uptime loss on the take-up station. Fewer breaks lift the uptime you feed into the Wire Spool Capacity tool, so cutting the 3.2% rate directly raises good spool output.

Wire Drawing & Rod Processing calculator

Breakage Loss Calculator

Breakage Loss expresses how often wire snaps during drawing as a percentage of the lengths or coils you ran, and then measures that against the break-free target you hold the line to. Drawing supervisors and metallurgists watch it because every web break means rethreading, a weld or scrap end, lost line speed, and a die that just took an impact. A break rate that creeps up is usually the earliest signal that inclusions, a worn die, wrong lubrication, or an over-aggressive reduction schedule is developing. Tracking it per shift keeps a small problem from becoming a scrap crisis.

What this calculator does

Breakage Loss expresses how often wire snaps during drawing as a percentage of the lengths or coils you ran, and then measures that against the break-free target you hold the line to.
Use it when breakage loss in wire drawing and rod processing needs a clean rate and gap-to-target you can put on a tier board.
It computes the wire break rate as breaks divided by total lengths drawn, then reports the gap between your target break-free rate and that break rate.

Formula used

Breakage Loss rate = affected amount ÷ total amount
Gap to target = target rate - calculated rate

Inputs explained

Wire breaks in the run:
Total lengths (or coils) drawn:
Target break-free rate:

How to use the result

Use it at shift end or after a problem run to quantify break frequency and compare it against the standard you set for the line.
A raw break rate ignores the cause and severity of each break; two shifts with the same rate can differ hugely if one break scrapped a full coil and another dropped a short end.

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).
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 wire breakage loss? Divide the number of breaks by the total lengths or coils drawn. With 8 breaks across 250 lengths, the break rate is 8 / 250 = 3.2%.
What is a good breakage rate in wire drawing? It depends on gauge and material, but fine ferrous wire lines often target well under 1% break-per-coil. A 3.2% rate like the example signals a process worth investigating before it eats yield.
What does the gap-to-target number mean here? The tool compares your target rate (95% in the default) against the calculated 3.2% break rate, giving a 91.8-point gap. Read it as how far the measured figure sits from your reference, then decide which direction your target is defined in.
What causes wire to break during drawing? Common culprits are non-metallic inclusions in the rod, worn or wrongly-sized dies, insufficient or degraded lubricant, excessive reduction per pass, and off-temperature material. A rising break rate usually points to one of these.
Should I count every break or only breaks that scrap material? Be consistent. Most shops count every web break because each one costs line speed and threading time, but if you only care about scrap you can count scrapping breaks instead — just don't switch definitions between shifts.

Last reviewed 2026-05-12.