Seiko 6T63A,8T63A Technical Manual

PARTS CATALOGUE / TECHNICAL GUIDE

Cal. 6T63A

[SPECIFICATIONS]

Cal. No.

Item

Interval of hands movement

Driving system

Additional function

Loss/gain

Regulation system

Gate time for rate measurement

Power

supply

Battery No.

Battery voltage

Battery life

Number of jewels

1/19

Crown

operation

Normal position

1st click position

2nd click position

Current consumption

Coil resistance

1 second

0 jewel

Stepping motor, 2 pieces

• Stopwatch function

60-minute stopwatch in one second increments.

• Second hand stop function

4002054 (COIL BLOCK A)

1.45 - 1.65 K

Ω

Use 10-second gate.

SEIKO SR936SW

Nil

1.55 V

Approx. 3 years

6T63A

• 3 hands (hour, minute, and

small second hand)

• 24 -hour indicator

• Date indicator

4002055 (COIL BLOCK B)

1.65 - 1.85 K

Ω

Free

Date setting(clockwise)

Time setting, hand position adjustment / resetting the circuit

Monthly rate: Less than 20 seconds (worn on the wrist at the tempera-

ture between 5 and 35)

• Diameter

Outside: Ø 30.8 mm Casing: Ø 29.0 mm

• Height: 5.1 mm

Movement : Less than 2.70 μA
Circuit block: Less than 0.70 μA

SPECIFICATIONS

2/19

Cal. 6T63A

Cal. 6T63A has a new structure employing one crown and two buttons. The construction of chronograph
mechanism is based on Cal. 8R28 mechanical chronograph watch by using the one-piece 3 pointed reset
hammer. While other Swiss-made watches are using separate hammers which require an assembly and
adjustment of the hammers, the one-piece hammer design realizes maximum durability and stability of
the component and easier maintenance. It is also equipped with the self-alignment function for all counting
hands to return to zero positions instantaneously.

This is the multi-display analogue watch featuring a stopwatch function.

●

The time is indicated by the 24-hour, hour and minute hands, and a small second hand.

●

The stop watch can measure up to 60 minutes in one second increments. After 60 minutes,

it will stop automatically.

● Measurement performance

Displays the elapsed time with the 2 designated STOPWATCH hands.

Measures up to 60 minutes in one second increments.

● Button operation (Crown position: Normal position)

Button A: START/STOP
Button B: RESET

1. STOPWATCH FUNCTION

Cal . 6T63A

a b c

Hour hand

Minute hand

STOPWATCH 1/5-second hand

STOPWATCH minute

hand

Small second hand

a: Normal position
b: First click
c: Second click

24-hour hand

A

B

CROWN

When pushin g th e re se t bu tton

the HAMMER OPERATING LEVER

B moves automatically to
ke ep ap propr iate bal ance of th e

HAMMER position.

CHRONOGRAPH

COUPLING LEVER

HAMMER OPERATING

LEVER A

HAMMER OPERATING

LEVER B

HAMMER HAMMER

HAMMER OPERATING

LEVER B

FE ATUR ES

START

RESET

SPECIFICATIONS

3/19

Cal. 6T63A

After installing the battery, pull out the crown to the second click position. And then follow the
instructions below to correct the hand positions and set the time.

NECESSARY PROCEDURE AFTER BATTERY CHANGE

Pull out to the second click position when the small second hand is at
the 60 seconds position. The small second hand stops on the spot.

Crown

Push back in to the normal position in accordance with a time signal.

Crown

Watch starts moving with 2-second interval for 10 seconds. Wait until it moves with
1-second interval.*
* Do not move the crown before it ends.

Button B

Press Button B for longer than 2 seconds.
The STOPWATCH minute hand turns a full circle.

● Standard measurement

Button A

START

→

Button A

STOP

→

Button B

RESET

● A ccumulated elapsed time measurement

Button A

START

→

Button A

STOP

Button A

STOP

→

Button B

RESET

→

Button A

RESTART

…→

Restart and stop of the stopwatch can be repeated by pressing button A.

●

Measurement functions

Accumulated elapsed time measurement and split time measurement are available.

Cal. 6T63A

PARTS LIST

4/19

DAT E I NDI CATOR
MAINTAINING
PL AT E SC REW
0012354

1

2

3

4

5

6

7

DAT E I NDI CATOR
MAINTAINING
PL AT E
0808052

DATE DIAL
0878***

DAT E J UM PER
0810019

DATE CORRECTOR

WHEEL

0806002

INTERMEDIATE

SMALL HOUR HAND WHEEL

AND PINION
0817048

SMALL HOUR HAND WHEEL

0157***

[ Cross section ]

7

3

For parts and , please refer to the page 10.

Disassembling procedures Figs. : 1 61

Reassembling procedures Figs. : 61 1

AO-2

Type of oil Oil quantity mark

NORMAL QUANTITY

AO-3

S-6

LIBERAL QUANTITY

SMALL QUANTIT Y

Cal. 6T63A

PARTS LIST

5/19

HOUR WHEEL

0273***

8

9

SWITCH LEVER
HOLDER SCREW

012354

10

11

12

14

13

SWITCH LEVER
HOLDER

0837005

SWITCH LEVER A

4450017

SWITCH LEVER B

4450018

DATE CORRECTOR
SETTING
TRANSMISSION

WHEEL B

0962013

DATE CORRECTOR
SETTING TRANSMISSION

WHEEL C

0962891

For parts , please refer to the page 10.

8

Cal. 6T63A

PARTS LIST

6/19

*1

*1

*2

*2

15

SWITCH SPRING SCREW

0016121

17

SECOND COUNTING

WHEEL FRICTION

SPRING
0353018

18

CHRONOGRAPH

BRIDGE
0190007

16

SWITCH SPRING

4250***

19

CHRONOGRAPH

COUPLING LEVER
0581007

25

TRAIN WHEEL

STOP LEVER
0894002

26

HAMMER OPERATING

LEVER A
0587004

20

HAMMER OPERATING

LEVER B
0587006

HAMMER

0585013**

15

SWITCH SPRING SCREW

0016121

21

SECOND
COUNTING

WHEEL

0888***

22

POSITIONING
ARBOR
0685002

23

MINUTE
COUNTING

WHEEL

0740***

24

For parts , please refer to the page 10 and 11.

For parts and , please refer to the page 10.

For parts , , , , and , please refer to the page 12 and 13.

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16

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