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ENEnglish繁中繁體中文ESEspañolARالعربيةFRFrançaisITItalianoPTPortuguêsRUРусскийDEDeutschJA日本語VITiếng ViệtKO한국어THไทยTRTürkçe

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Engineering Calculator · 112

Compression Set Percentage Calculator

Calculate compression set from original specimen height, spacer height and height after the prescribed recovery period.

Seal geometry
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Live calculation

Enter the known values.

Units remain visible beside every field and result. Change any input to recalculate immediately in your browser.

01

Inputs

02

Results

Compression set20%
Imposed test deflection2.5mm
Residual height loss0.5mm
Height recovery of imposed deflection80%

Formula
CS=100t0−trt0−tsCS=100\frac{t_0-t_r}{t_0-t_s}

The calculation runs locally in this browser. Values are not submitted or stored by this tool.

Direct answer

What this result means

Compression set is the residual loss of specimen height divided by the imposed test deflection, expressed as a percentage. An original height of 10 mm, spacer height of 7.5 mm and recovered height of 9.5 mm give 20% compression set. Compare compounds only under compatible test conditions.

Compression Set Percentage Calculator engineering relationship diagramOriginal height t₀ and spacer height tₛ define the imposed deflection. Height tᵣ is measured after release and the specified recovery period. The three diagram stages show original, compressed and recovered specimens. Height recovery is 100 − CS, not a measure of retained sealing force. This dedicated schematic represents compression set three heights and is not to scale.Original t₀Spacer tₛRecovered tᵣRECOVERY AFTER COMPRESSION · TOOL 112Original specimen heightCompression set
Calculator-specific engineering relationship diagram — schematic, not a product drawing, and not to scale.

Formula & theory

Make the assumptions visible.

Original height t₀ and spacer height tₛ define the imposed deflection. Height tᵣ is measured after release and the specified recovery period. The three diagram stages show original, compressed and recovered specimens. Height recovery is 100 − CS, not a measure of retained sealing force.

Calculation relationship
CS=100t0−trt0−tsCS=100\frac{t_0-t_r}{t_0-t_s}

Original height t₀ and spacer height tₛ define the imposed deflection. Height tᵣ is measured after release and the specified recovery period. The three diagram stages show original, compressed and recovered specimens. Height recovery is 100 − CS, not a measure of retained sealing force.

Formula terms

Variables

t₀Original specimen height before the testmm
tₛSpacer height fixing the compressed specimen heightmm
tᵣRecovered height measured after the specified release and recovery proceduremm

Use sequence

From measurement to review

  1. Record the test method, compound, specimen size, compression, duration and temperature.
  2. Enter original height, spacer height and recovered height measured after the prescribed recovery procedure.
  3. Compare compatible test reports and investigate unusual dimensions before using the percentage in material selection.

Limits

What this calculation does not confirm

  • This height-based equation describes a constant-deflection compression-set test; it does not calculate installed seal squeeze.
  • Results below 0% or above 100% are displayed without clipping. Investigate swelling, shrinkage, measurement error or incompatible test conditions.
  • Recovery of height does not quantify retained contact force, leakage, service life or product suitability.

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Calculator FAQ

Use the number without losing the engineering context.

These answers clarify what the tool calculates and where a product-specific review still begins.

01Calculator guidanceWhat do 0% and 100% compression set mean?

At 0%, the recovered height equals the original height. At 100%, it equals the spacer height. These describe recovery of the imposed height deflection under the stated test conditions.

02Calculator guidanceDoes 20% compression set mean 80% sealing force remains?

No. Height recovery and retained force are different measurements. Force relaxation requires a suitable force-based test, and complete-gland sealing performance requires product-specific evidence.

03Calculator guidanceWhy can compression set be negative or exceed 100%?

Swelling can produce a recovered height above the original; shrinkage can produce a height below the spacer. Check specimen dimensions, conditioning, recovery procedure and the applicable reporting rules. The calculator preserves the measured arithmetic instead of hiding it.

Product selection support

Connect the calculation with cable-entry product options.

Bepto Cable Glands can help relate a preliminary result to the product family and current model information for your application. You can start with the details you have; a complete drawing package is not needed to ask a question.

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