RuneScape Classic Wiki
The main RuneScape Wiki has an article on: Steel Scimitar
The Old School RuneScape Wiki also has an article on Steel Scimitar.

A steel scimitar is a scimitar that requires level 5 attack to wield. They can be made from two steel bars at level 35 smithing, yielding 75 smithing experience, or purchased from Zeke's Superior Scimitars in Al Kharid, which stocks two at the price of 400 coins each.

For lower levelled players, the Steel 2-handed Sword makes for a more efficient melee weapon.

Dropped by

Monster Combat level Quantity Rarity
Lesser Demon 79 1 3Uncommon