Sierra vs. serrucho
The Spanish words 'sierra' and 'serrucho' both translate to 'saw' in English, but they refer to different types of tools.
Sierra
'Sierra' is generally used to refer to larger saws and can also mean a mountain range due to the shape resemblance. It includes hand saws, electric saws, and circular saws.
Utiliza una sierra para cortar el tronco.
(Use a saw to cut the log.)
Las herramientas eléctricas incluyen una sierra circular.
(The power tools include a circular saw.)
La Sierra Madre está cubierta de nieve.
(The Sierra Madre is covered with snow.)
Serrucho
'Serrucho' specifically refers to a hand saw, usually of manageable size for manual cutting.
Necesitas un serrucho para cortar las ramas del árbol.
(You need a handsaw to cut the tree branches.)
El carpintero afiló su serrucho antes de empezar el trabajo.
(The carpenter sharpened his handsaw before starting the job.)
Encontré un serrucho viejo en el garaje de mi abuelo.
(I found an old handsaw in my grandfather's garage.)
Summary
While both words translate as 'saw', 'sierra' refers to various kinds of saws, including electric and circular saws, as well as mountain ranges due to their shape. 'Serrucho', on the other hand, is specifically a handsaw used manually for cutting wood or branches.