Our chisels are lapped flat to .00005" variance per inch.... you should not have to flatten them. You will have to dress or stone the bevels if you find them sharp.
Great specs,
@Rob Lee. I have several LV chisels and plane blades and I've never had an issue with out of flat. The question that I have is, what is the equivalent Waterstone grit to which the backs are smoothed at the factory? They kind of look grayish out of the box, so I'm always tempted to smooth out the backs with waterstones starting at maybe 1000 grit. However, I suspect that would just ruin the finish that you've already put on them, because it -feels- like they are smoother than that, even though it doesn't look like it.
The reason that I'm concerned is that the final finish on the back should match the final finish on the bevel. Otherwise one of the two planes (back and bevel) that meet at the edge is rougher than the other, and the edge will only be as sharp as the roughest of the two. If I hone the bevel to 8000 grit, but the back is only smoothed to 2000 grit, the edge will only cut and last as well as if both were only sharpened to 2000 grit. So if LV is smoothing the backs to 8000 grit and I'm honing the bevel to 4000, I'm wasting the nice polishing job that you've done on the back. On the other hand, if LV is smoothing the back to 2000 and I'm honing the bevel to 8000, I'm wasting my time.
Even worse, if LV polishes the backs to 4000, and I try to polish the backs starting with a 1000 grit stone, I'm just making a huge amount of rework for myself, and probably destroying the 0.00005" spec on flatness in the process. On the other hand, if LV is polishing the back to 1000 grit, and I start trying to polish it at 8000 grit, I will be polishing a very long time before I get the back polished to 8000.
I've ordered an endoscope to check out my edges, but haven't used it yet. That's the only way I can think of to check for myself.