Seiko 6217-8001 (62MAS)…

It’s been a while since I’ve written about a Seiko on the blog, but here’s one of their iconic vintage divers, a “62MAS”.

(Click pictures to enlarge)\

I’ve written about a good few Seiko divers in the past, but this one is historically significant to the brand as it was their first model made specifically for scuba divers.

First released in 1965, the 62MAS was a significant change to the majority of Seiko’s output. It was the first diver to feature an external rotating bezel, and a water resistance of 150 meters. Prior to the 62MAS, the only watch with similar leanings was the Seiko Sportsmatic SilverWave, with an internal rotating bezel and a water resistance of 30 meters.

Although the watch arrived in good cosmetic condition, it had already been on quite a restoration journey. As you can see in the picture below, when the owner bought the watch it wasn’t in good shape at all, missing its external bezel, and having an inscription on the case side.

Having sourced all the missing parts, the owner sent the watch to two other craftsmen to have the dial and hands relumed, and the case refinished before it landed on my bench. My job was to make sure everything was mechanically sound.

Opening the caseback revealed a relatively clean and tidy Seiko Cal. 6217A, though it did have underlying problems. There was a distinct click in the keyless works when setting the time, and the date quickset was very hit and miss, both common problems to Seiko 62xx calibres when wear starts to set in.

This watch has a quickset date, which means that when the crown is pulled out to the first position, it is then possible to cycle through the dates until the right date is showing in the aperture. In watches with significant wear, the mechanism can skip or in extreme cases, the quickset doesn’t work at all.

Looking closely at the date corrector on the left in the picture above, you can see that there is wear on the underside of the teeth. Wear eats away at the teeth until they no longer have sufficient contact to push the date ring forward. Instead, the corrector tooth just skips over the top of the date ring tooth, increasing the wear on both parts. When this starts to happen, the only option is to replace the part with one in better condition, often acquired from a donor movement as new parts are no longer available.

It’s a similar story for the clutch wheel, pictured above right. When viewed with a microscope, you can see that the teeth are severely worn and one of them had chipped off at the end which was causing the clicking in the mechanism when setting the time. Again, the only option is a replacement part.

With the parts replaced and the rest of the movement serviced, things went smoothly from there on. Here’s the watch re-assembled and ready for action once again.

Like several other Seiko watches from this period, the caseback detail has often worn smooth after 40+ years of wear. It was great to see that wasn’t the case with this watch, the dolphin is still crisp and all the print legible.

For more information about the features and history of the 62MAS, check out this excellent collector’s/buying guide.

Rich.

** Many thanks to Duncan Hewitt for letting me feature his watch on the blog. **