Rolex 4130 hairspring protection block

[timuS]

Hello friends,

Recently in an article where the author mentions of an upgrade to the caliber 4130. I have quoted the relevant portion verbatim:

"A more notable upgrade that they introduced is a hairspring protection block, which eliminates any possible risk of the lower coils of the hairspring tangling in the hairspring's overcoil when the watch endures a hard blow."

Here is the article link:

https://www.hodinkee.com/articles/inside-rolex

I searched the web, but not much is available on this. Would you have any more data on what this really is?

Thanks!

[sheldonsmith]

I recall reading that as well and, like you, I have not seen it referenced anywhere else, including Rolex's press materials.

[Ironstark]

It is a metal block shaped and designed to fit inside the overcoil and between the main (flat section) of the hairspring and the underside of the balance bridge.
It almost completely eliminates the possibility of the hairspring becoming entangled should the watch receive a heavy blow.
As with all such upgrades it is not usually referred to or charged for but is applied during a routine service to ensure the watch is even more reliable and accurate after the service.