Seiko SLT019P1

cal. 8F56

Factory Spec. 20 SPY

Thermoinsensitive: High Frequency (196 kHz)

User Adjustable: No (pattern cutting may be possible)


I bought this watch for an example of an 8F movement. It is a movement that is no longer made and which has come in for quite a bit of stick for failing to live up to its 20 SPY accuracy claim. I haven't got a manual for the 8F56, but the manual for other 8F movements suggests that adjusting the rate may be possible by pattern cutting. Pattern cutting involves an irreversible snipping of tiny wires. The rate can be changed only by rather limited amounts, and the pattern can be cut only twice. As I am timing this watch, I haven't yet taken out the battery to see whether the pattern wires exist in this movement.

UPDATE - I have sold this watch (and was rather sorry to see it go).

Some data for this watch is missing because it was not subjected to comprehensive tests.

Parent Company Seiko Holdings Corporation
Brand Seiko
Model Series unknown
Model Name unknown
Model Number SLT019P1
Case Number 0030
Serial Number 930216
Approx. Date of Manufacture March 1999 (or 2009?)
Calibre (mvt maker) 8F56
Calibre (brand) 8F56
Factory SPY 20
TC Appproach Thermoinsensitive: HF
Frequency (XO 1) 196 kHz
Frequency (XO 2) n/a
Rate Adjustment none
Major Inhibition Period n/a
Minor Inhibition Period unknown
Power Disposable cell
Cell Number BR2412
Case Back Screw
Water Resistance 10 bar
Features 4-hand, Arabic numerals at 12, 6, 9
  24hr GMT hand
  Rotating bezel
  Date (perpetual)
  Independently adjustable hour hand
Timing Results Basic data  &  Further details
Images Photos - Large File Sizes!