Is it possible to recognise hardware (router or network card) just by its MAC address?

You can find the manufacturer of the device.

The first 6 hex digits of a MAC address contains the ID number of the adapter manufacturer. you can look the manufacturer here

some what older documentation here

Nmap contains an extensive file with this table aswell

The first 6 characters of a MAC address identify it's the manifacturer of the NIC (the lan adapter). So by finding the NIC's manifacturer you could possibly identify the brand of the device, but it's not a 100 % because the Device could be assembled fromvarious parts , produced by other companies.

You can easily identify it by using some free software. TMAC is pretty cool. It allows you to change your MAC address as well, so it exemplifies why you can't always rely on the MAC address for deducing what is the device containing it.