Very important warning: when punching the 4 letters of each word on each of the washers, make sure you also punch the seed index of each word/washer (i.e., its order position in the seed). If you don't, and you just rely on the washers being arranged in proper order in the screw, you may mess things up if you or someone else unscrews it and the washers fall off. If the order is lost, the seed is also effectively lost.
If the seed phrase averages 64 characters, that's 16 washers. The number of permutations is n!, which is 20,922,789,888,000 - about 21 trillion.
This guy cracked 1 trillion seeds in 30 hours using cloud computing, so while it could take a month, the seed should be recoverable.