A581
The A581 is a 17 jewel, manual wind watch movement which was designed and manufactured by the Shanghai Watch Factory . Its design is very closely based on that of the Swiss AS 1187 movement, but it is not an exact clone. The A581 was Shanghai Watch Factory's first mass-produced watch movement, and was manufactured from 1958 to 1967. Together with its derivative movements, the A581 was the mainstay movement of Shanghai branded watches until the introduction of the SS1 movement.
Design
The A581 has 17 jewels and an 18,000 bph escapement. The balance wheel has poising screws and the balance cock does not feature any shock-resistance. The mainspring provides a 40 hour power reserve.
