Two feats from the original 1933 King Kong.
Kong snaps chains[]
The iconic scene in which Kong escapes. The chains are said to be made of chrome steel, which has a tensile strength of 325000 psi. Now, Kong's size shifts all throughout the movie, but for these feats I will give him the height he was advertised at, 50 feet. Gonna use this as an example.
Kong = 15.24 m / 396 px
Chain thickness = 7 px / 0.269393939 m
Chain opening thickness = 8 px / 0.307878787 m
Chain opening length = 8 px / 0.307878787 m (More or less the same)
Chain volume (now all in cm) = 30.7878787 x 26.9393939^2 x 2 + 30.7878787^3 x 6 = 219789.208471 cc
Fragmentation of steel = 208 J/cc x 219789.208471 = 45716155.362 J (10.92642336568 kg, Small Building level) and 4.57161554 × 1013 pascals (45716155.4 megapascals or 4661750485.6398 tonnes per square meter)
Lifting strength: Area of the chain - formula = π / 4 x diameter (of the bar) ^2 = π / 4 x 26.9393939^2 = 569.987750302 square cm
Class G lifting strength... yeah probably not lol
Kong bends a metal door[]
After escaping, Kong busts down a metal door, bending it in the process.
Using his body's width in the standard posture he walks in, I was able to find the width of the door, and the thickness and height were easy enough, then I converted the numbers in meters to inches for the calculator. I used stainless steel (Ultimate tensile strength: 73200 psi) for the material used.
Class M, somewhat casually as well. Using this model as example, assuming Kong pushes it down 1 meter (though what he does is more impressive), we find that all those tons turns into 502867752.29599994 N or 502867752.29599994 J which equals 120.1882773174 kg of TNT (Small Building level)
Ugarik's calc[]
The width is 0.347 m and the length is 12.8 m.
Plastic section modulus: (12.8*0.342^2)/4 =0.374 m^3 or 374284.8 cc
73200 psi is 505 MPa
374284.8 * 505 = 189013824 Nm
Force: 4*189013824/15.24 = 49609927.6 N or 5058804.75 kgf (Class M)
As for work: 5058804.75 N * 2.31 m = 11685839 J (2.792982552581 kg of TNT, Wall level+)
Bonus: 2005 Kong lifts a stone house[]
We have nothing for 2005 Kong's lifting strength, but via the calculations of this house Kong lifts here, I can find the weight to be...
In the Class 25 territory. It makes sense considering Kong can lift and throw a V-Rex (which dwarfs its 10-ton T-Rex ancestor) with one arm.
And yes, the house is evidently made of stone, even if it's hard to see in the video.