Is his strength level 20 tons?

About 40 tons minimum currently. Upwards of 75+ tons if angry, adrenaline driven or determined.

About 20-40 tons based on consistent feats. Spidey also once managed to hold up the weight and safely land a small private jet in Slott's first Amazing Spider-Man during the Alpha story arc I believe. Those things are supposed to weigh over 60 tons or something, can't remember the exact figures. Oh and he's also held up a building supported by his webbing so take that high end feat for what you will.

according to his feats. he is more of a 40 toner. he has landed a 75 ton jet on his back, lifted a huge portion of the daily bugle, took down a train cartage in one flick, knocks out humans with the tap of his head, shattered the 3rd hardest metal and broke scorpions jaw in 1 punch. he has also went thousands of tonnes up in occasions. he has effortlessly defeated hulk once or twice. his leg muscles allow him to jump 3 stories high. spider-man shouldn't be a 20 toner. he should be a 40 toner. his maximum strength allowed him to lift many heavy objects that were thousands of tonnes. i think his strength level is beyond 20 tons. like it should be 40 tones or 50 tones. he knocked out thor and rhino with his bare hands. he even knocked out the hulk, i'd say he is at 40 tonnes.

25 tons but he has higher end feats. On average I'd say 25 tons, only more when under duress