- Kingdom: Animalia
- Phylum: Mollusca
- Class: Bivalvia
- Order: Euheterodonta
- Family: Pharidae
- Scientific name: Ensis magnus
- Norwegian: stort knivskjell
The sword razor is the largest and most common razor shell along the Norwegian coast. It can reach a length of 20 cm. The dorsal margin (the back) is straight while the ventral (front) margin is curved. It can easily be confused with the slightly shorter (15 cm) and more banana shaped (both margins are curved) E. ensis.
It lives buried in the sand, usually just below the subtidal zone. Registrations have been made as deep as 100 meters.
It is registered from Troms, Norway to the west coast of Africa.