GMT Bezel Insert Sizes - Acrylic and Sapphire Models

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springer
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GMT Bezel Insert Sizes - Acrylic and Sapphire Models

Post by springer »

Below is some info that you might find helpful when attempting to determine the size of a GMT bezel insert - especially if it doesn't fit properly. Additionally, there is another thread here in the Reference Library which identifies the visual differences between the acrylic 1675/16750 inserts and the sapphire model inserts.

I utilized several examples of inserts for the GMT 1675/16750 acrylic and GMT 16700/16760/16710 sapphire inserts which are noted below. One thing that I observed when measuring these inserts was that no two examples measured the exact same size. The measurements below were taken with digital dial calipers:

ACRYLIC CRYSTAL MODELS
New, NOS insert 1675/16750 insert - OD:37.74mm, ID: 30.12
Used insert 1675/16750 - OD: 37.54mm - 37.74mm*, ID: 30.10 - 30.20mm*

* The inner and outer measurements for these inserts will vary due to manufacturing, age, stretch, compression and overall use.

SAPPHIRE CRYSTAL MODELS

New or Used sapphire crystal 16710/16700/16760 insert - OD:37.55mm,* ID:30.67mm**

** * The inner and outer measurements for these inserts will vary slightly due to manufacturing, age, stretch, compression and overall use.

There are also some charts on the internet at various web sites that contain GMT bezel insert measurements that vary somewhat from the measurements I listed above. Several factors can play into the discrepancies, but the measurements should be close.
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