A fuerza de alisar, logramos el mismo grosor.

A fuerza de is an idiomatic expression meaning something like:

• by dint of
• through repeated effort
• by doing something over and over
• as a result of insisting on something

So a fuerza de alisar suggests that the result was achieved through repeated smoothing/flattening.

It often carries the idea of persistence, effort, or repetition:

• A fuerza de practicar, mejoró mucho.
  = By practising a lot / Through sheer practice, he improved a lot.

After a fuerza de, Spanish normally uses an infinitive when talking about an action in a general way.

So:

• a fuerza de alisar
• a fuerza de repetir
• a fuerza de intentarlo

This is very similar to English structures like by smoothing, by repeating, through trying.

You would not normally use a conjugated verb here.

Alisar means to smooth, to flatten, or to make even/smooth.

The most natural English translation depends on the context. It could refer to:

• smoothing dough, clay, wood, fabric, etc.
• making a surface more even
• reducing irregularities

So in this sentence, it suggests that by repeatedly smoothing or flattening something, the same thickness was achieved.

The comma separates the introductory phrase a fuerza de alisar from the main clause logramos el mismo grosor.

So the structure is:

• A fuerza de alisar, = introductory adverbial phrase
• logramos el mismo grosor. = main statement

In English, this is similar to writing:

• By smoothing it repeatedly, we achieved the same thickness.

The comma helps readability. In short sentences, punctuation can vary a bit, but this comma is perfectly normal.

It can be either one, because logramos has the same form in:

• present tense: we achieve
• preterite: we achieved / we managed

So the sentence is ambiguous by form alone.

How do you know which it is?
You need context.

• If the speaker is describing a general process, it could be present.
• If the speaker is talking about a completed result, it could be preterite.

In many contexts, with a sentence like this, learners often interpret it as preterite:
By repeated smoothing, we managed to get the same thickness.

Lograr means to achieve, to manage to, or to succeed in getting.

It often implies that the result took effort or was not automatic. That fits well with a fuerza de, which already suggests persistence and effort.

So logramos el mismo grosor is not just we got the same thickness. It has more of a sense of:

• we managed to achieve the same thickness
• we succeeded in getting the same thickness

Grosor is a noun meaning thickness.

• el grosor = the thickness

Grueso is usually an adjective meaning thick:

• una capa gruesa = a thick layer

So:

• el mismo grosor = the same thickness
• igual de grueso = equally thick

Both can relate to thickness, but they are different parts of speech:

• grosor = noun
• grueso = adjective

Because grosor is a masculine noun:

• el grosor

So mismo must agree with it:

• el mismo grosor

If the noun were feminine, you would use la misma:

• la misma textura
• la misma forma

Agreement in Spanish follows the noun, not the English translation.

It means the same thickness.

Here, mismo means same, and it is used with the definite article:

• el mismo grosor = the same thickness

This is a very common structure in Spanish:

• la misma idea = the same idea
• el mismo tamaño = the same size
• la misma cantidad = the same amount

Because Spanish often omits subject pronouns when the verb ending already shows who the subject is.

• logramos already tells you the subject is we

So nosotros logramos is possible, but usually unnecessary unless you want emphasis or contrast.

For example:

• Nosotros logramos el mismo grosor, pero ellos no.
  = We achieved the same thickness, but they didn’t.

In the original sentence, leaving out nosotros sounds natural.

Yes, it is fairly common and natural, though it sounds a bit more expressive than a plain neutral alternative.

It is often used to emphasise persistence or repetition:

• A fuerza de insistir, consiguió entrar.
• A fuerza de practicar, aprendió muchísimo.

So it is not strange or literary, but it does add a flavour of effort, insistence, or repetition.

Yes. Depending on tone and context, Spanish offers several alternatives:

• De tanto alisar, logramos el mismo grosor.
  = By smoothing it so much / After so much smoothing, we achieved the same thickness.

• Alisando una y otra vez, logramos el mismo grosor.
  = By smoothing again and again, we achieved the same thickness.

• Después de alisar mucho, logramos el mismo grosor.
  = After smoothing a lot, we achieved the same thickness.

Compared with these, a fuerza de alisar sounds especially good when you want to stress effort and persistence.

The sentence itself is not strongly regional. A speaker in Spain would understand and use it naturally, and so would many speakers elsewhere.

What matters more is that:

• a fuerza de is standard Spanish
• alisar is standard Spanish
• grosor is standard Spanish

So this is not a specifically Spain-only sentence, but it fits Spain Spanish perfectly well.