SEIKO S-916 Silicone Grease Applicator (Silicon Greaser) – Gasket Grease for Watch Cases | Original SEIKO Japan

Original SEIKO service tool, directly imported from Japan – rarely available outside of Japan.

The Silicon Greaser S-916 from the official SEIKO service program is the tool for the crucial step in waterproofing a watch: the even greasing of the gaskets. The container holds a sponge pad soaked in silicone grease – the gasket is briefly placed between the halves of the pad and pressed, and when removed, it carries a wafer-thin, uniformly even film of silicone all around. Precisely this uniformity is the key: it maintains the water and gas tightness of the screw connection and keeps the gasket permanently pliable.

In contrast, manual greasing with a finger or directly from the container can easily lead to uneven application – too much grease in one spot (which can migrate into the movement), too little in another (where the gasket remains dry). In Japanese workshops, the Greaser is therefore used with every battery change and every service before the case back is closed. If grease delivery decreases, the pad is simply refilled with SEIKO silicone grease A-MY451 (TSF-451, available separately in our shop) – making the Greaser a tool for decades.

What distinguishes this tool from European counterparts:

Gasket greasers based on the sponge pad principle are also available from Swiss manufacturers – however, the Horotec/Bergeon variants are significantly higher in price, while simple Far Eastern imitations compromise on pad quality and grease specifications. The S-916 comes from SEIKO's own service program (SEIKO Service Center Co., Ltd., Made in Japan) and is pre-filled from the factory with the silicone grease that SEIKO specifies for its case gaskets. Those who maintain Japanese watches to factory standards work with precisely this tool – not regularly available in Europe.

Specifications:
Container with silicone-soaked sponge pad, refillable (with SEIKO A-MY451/TSF-451)
Reference: SEIKO S-916

Condition:
New, originally packaged

Note
Improper use can damage watches. Use at your own risk.