Part 5 What they don't tell you when you buy a 2015 Seiko Prospex Marinemaster Professional 600m Spring Drive SBDB011 JDM

Part 5...habitual now

Continuing from Part 4,


12)

What grade of titanium does Seiko use for the SBDB001(SBDB011) watch case? Does it use grade 5 titanium or the softer, easier to machine grade 2 titanium? Of course, there would be in addition surface hardening technology(Brightz) and hard coating(Diashield for SBDB011) that would be further applied to the base material.

1. Grade 5 titanium consists of an additional 6% aluminium and 4% vanadium.
2. Grade 5 titanium has considerably higher strength than grade 2 titanium or 316L stainless steel.
3. Grade 5 titanium has excellent strength and corrosion-resistance.
4. Grade 5 titanium is much more difficult and costly to machine than grade 2 titanium.
5. Most European watchmakers will specifically make a point to mention grade 5 titanium if they were using it else it would just be 'titanium' if it was an inferior grade. See the CX Swiss Military 20,000ft Diver or the Tudor Pelagos.

Seiko never mention specifically on the web AFAIK but I've found documentation in Tokunaga's book indicating grade 5 titanium being used as the base material for the watch case and bracelet.

Grade 5 Titanium mentioned for the SBDB001. See the green highlight. For the Japanese reader, if a mistake was made please comment that I may correct it. Thanks in advance.

Only one point...this time round...