Rolex Datejust 684874F 40 mm: what to check on a used piece

Rolex Datejust 684874F 40 mm is the reference in this note. Lay the watch on a plain cloth under a lamp. Read the case flank before you read the dial, because the flank shows tool marks and a polished edge that a photo crops away. Count the lugs. Note whether they are drilled. A drilled lug means the strap can be changed with a spring bar, and the hole should be round rather than oval from a bar that was forced. Flex the bracelet at the first link. Stretch that does not return is wear, not a style. The clasp should close with one click and sit flat. If it stands proud, the fold has been bent. Look through the crystal at an angle. Dust on the inside of the glass is a different problem from a scratch on the outside. Write which one you see. Then set the hands and watch them for a full minute so you can say whether the seconds hand ticks or sweeps. That single observation tells you the kind of movement in the case. Record it next to the reference engraving. The two notes belong together.

How it differs

Rolex Datejust 684874F 40 mm is a dress case. The checks are the date window if it has one, the thinness of the lugs, and the strap or bracelet that was fitted later. A leather strap is a wearable part, not the watch. Look at the lug gap and the keeper. People change straps, hands, and crystals on dress watches. The case engraving is still the reference.

What to check on a used piece

What to check on a used Rolex Datejust 684874F 40 mm starts with the engraving. The reference to read is 684874F. Measure the case. Listings often say 40 mm, and the ruler is the check. Then check end-link play, clasp fold, and whether the hands pass each other. There is no price in this note.

Common mods

Common changes are a new strap, a replaced crown, and a crystal. The date disk, when there is one, should match the dial in color and in height. A disk that sits high or low is a note for a watchmaker, and it is still the same reference.

What people change

On the Rolex Datejust 684874F 40 mm, people change the bracelet, the case, or the movement.