Shock Protection Symbol — What This Mark Means
A marking indicating the movement incorporates a shock protection system for the balance wheel. Common systems include Incabloc, Diashock, and Parashock.
What This Usually Means
Shock protection systems use spring-loaded jewel settings to absorb impacts and protect the delicate balance wheel pivots from breaking. Without shock protection, dropping a mechanical watch could shatter these pivots, resulting in an expensive repair. This feature became standard on quality movements from the mid-20th century onward.
Where to Find It
Typically engraved or printed on the movement, visible through an exhibition case back or when opened. It may appear as a brand name (Incabloc, Diashock, Parashock) or a generic symbol. Some case backs also mention it.
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Common Variations
Incabloc is the most widely used system, appearing across many Swiss and third-party movements. Seiko uses Diashock, while others use Parashock, KIF, or proprietary systems. The markings vary from text names to stylized symbols or logos.
Common Misconceptions
Shock protection doesn't make a watch indestructible. It protects the balance pivots from moderate impacts but won't save the movement from severe abuse. Also, the presence of shock protection doesn't indicate overall movement quality.
What to Do Next
If your watch was subjected to a significant impact and is no longer running or keeping poor time, the shock protection may have reached its limits. Have a watchmaker inspect the balance pivots and shock system.
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Frequently asked questions
What does shock protection actually protect?
It protects the balance wheel's delicate pivot points from breaking during impacts by using spring-loaded jewel settings that absorb shock.
Does shock protection make my watch shockproof?
No. It provides reasonable protection against moderate impacts but isn't designed for extreme abuse or repeated heavy shocks.
What's the difference between Incabloc and Diashock?
They're different manufacturers' implementations of the same concept. Incabloc is Swiss-made and widely used; Diashock is Seiko's proprietary system.
Do quartz watches need shock protection?
Quartz movements are inherently less fragile than mechanical ones in this regard, though some still include shock protection for the quartz crystal.
When did shock protection become standard?
It became widespread from the 1950s onward. Watches made before this era are significantly more vulnerable to impact damage.
Can shock protection wear out?
The springs can fatigue over decades but are typically checked and replaced during standard movement servicing.