Le pastiglie del freno stringono il rotore.

Because pastiglie is plural. The singular is la pastiglia.

• la pastiglia = the pad
• le pastiglie = the pads

The verb also matches this plural subject:

• la pastiglia stringe
• le pastiglie stringono

Del is a contraction of di + il.

• di = of
• il = the
• del = of the

So le pastiglie del freno literally means the pads of the brake.

This is a very common Italian structure for showing a relationship between two nouns.

Because Italian is referring to the brake as a unit or system: the brake. The sentence is saying that the brake pads belong to or are part of that brake.

So even though there are multiple pads, they are still the pads of the brake, not of the brakes.

Stringono is the 3rd person plural present indicative of stringere.

So:

• stringere = to squeeze / tighten / grip / clamp
• stringono = they squeeze / they grip / they clamp

It agrees with le pastiglie, which is plural.

Because stringere is an -ere verb, and in the present tense its they form ends in -ono.

For example:

• io stringo = I squeeze
• tu stringi = you squeeze
• lui/lei stringe = he/she squeezes
• noi stringiamo = we squeeze
• voi stringete = you all squeeze
• loro stringono = they squeeze

So stringono tells you the subject is plural.

Literally, yes, stringere often means to squeeze, to tighten, or to grip. In a mechanical context like this, English might naturally say:

• grip
• clamp
• press against

So even if the literal idea is squeeze, the best English translation depends on context.

Because rotore is a masculine singular noun, so it takes il.

• il rotore = the rotor

It is also the direct object of the sentence: the thing the pads are gripping.

Italian usually uses definite articles more regularly than English. So il rotore is completely normal Italian.

Even when English drops the in technical labels or headlines, Italian often keeps it:

• Le pastiglie stringono il rotore not usually
• Le pastiglie stringono rotore

There are two main clues:

1. Verb agreement

   • stringono is plural
   • le pastiglie is plural
   • so le pastiglie is the subject

2. Meaning and structure

   • il rotore comes after the verb and is what receives the action

So the sentence structure is:

• Le pastiglie = subject
• stringono = verb
• il rotore = direct object

This sentence uses the most neutral word order in Italian:

Subject + Verb + Object

• Le pastiglie
  • stringono
    • il rotore

Italian can change word order for emphasis, but this version is the standard, clear one. For a learner, this is the safest pattern to use.

Yes, but the meaning would change.

• le pastiglie del freno = the pads of the brake
• le pastiglie dei freni = the pads of the brakes

And:

• il rotore = the rotor
• i rotori = the rotors

So the original sentence is about one brake and one rotor, at least grammatically.

The singular version would be:

La pastiglia del freno stringe il rotore.

Changes:

• le → la
• pastiglie → pastiglia
• stringono → stringe

Everything else stays the same.