How to Measure a Coupling Pad Before Ordering a Replacement

Ordering the wrong coupling pad can lead to poor installation, excessive clearance, vibration or premature wear.

Before ordering a replacement coupling pad or coupling spider, it is important to identify the correct coupling model and verify the dimensions.

This guide explains what information you should collect before contacting a coupling manufacturer.

1. Identify the Coupling Type

First determine what type of coupling you have.

For example:

• MT
• GS
• GR
• HRC
• Other jaw coupling designs

If a model number is marked on the coupling or existing component, record it.

The model number can often make replacement identification much easier.

2. Measure the Coupling Pad Outside Diameter

Use a caliper to measure the outside diameter of the coupling pad.

Record the measurement in millimeters.

For greater accuracy:

1. Clean the component.
2. Place the caliper across the widest part.
3. Measure several times.
4. Record the most consistent measurement.

If the old coupling pad is heavily worn or deformed, the original dimension may be different from the current measurement.

3. Measure the Thickness

Measure the thickness of the flexible element.

Depending on the design, there may be more than one important thickness dimension.

If the coupling pad has an irregular shape, provide several measurements and photographs.

4. Count the Lobes or Pads

Many jaw coupling spiders have multiple lobes or flexible sections.

Count the number carefully.

Different coupling models can have different geometries, so the number and shape of the lobes are useful for identification.

5. Check the Coupling Hubs

If possible, also measure the metal coupling hubs.

Useful dimensions may include:

• Hub outside diameter
• Shaft bore
• Hub width
• Jaw dimensions
• Overall coupling diameter
• Overall coupling length

The hub information can help the manufacturer confirm the correct coupling pad.

6. Measure the Shaft Bore

If you are purchasing the complete coupling rather than only the flexible pad, provide the shaft bore dimensions.

Measure:

Shaft 1 + Shaft 2

because the two shafts may not necessarily have the same diameter.

7. Take Clear Photos

Photographs are extremely useful when identifying an unknown coupling pad.

We recommend sending:

Photo 1

The complete coupling.

Photo 2

The flexible coupling pad.

Photo 3

The metal hubs.

Photo 4

A close-up showing any model number or marking.

8. Provide the Application

Dimensions alone may not be enough for selecting the correct material.

Also provide:

• Motor power
• Operating speed
• Approximate torque
• Operating temperature
• Working environment
• Oil or chemical exposure
• Required quantity

This information helps the manufacturer evaluate the appropriate material and coupling configuration.

Coupling Pad Measurement Checklist

Before requesting a quotation, prepare:

What If You Don’t Know the Coupling Model?

Don’t worry.

If you cannot identify the model, send the manufacturer:

Photos + Dimensions + Existing Sample

A manufacturer may be able to identify the coupling pad based on these details.

For OEM production, a physical sample or engineering drawing can provide even more accurate information.

Custom Coupling Pad Manufacturing

Apex Coupling supports OEM and ODM production for flexible coupling components.

If your coupling pad is a non-standard size, we can evaluate production based on:

• Customer drawings
• Existing samples
• Dimensions
• Material requirements
• Hardness
• Application conditions

This is particularly useful for machinery manufacturers, distributors and replacement-parts suppliers.

Need Help Identifying Your Coupling Pad?

Send us a photo or drawing.

Email: ella@apexcoupling.com
WhatsApp: +86 13437856962

We can evaluate your requirements for an MT coupling pad, jaw coupling spider or other flexible coupling element.