I am amazed at this one...you will be too...

[kootenay joe]

I think it is a marketing term and each USA knife company uses it as they wish, but always for a big & strong knife, as has been pointed out already.
kj

[knife7knut]

Ray i think the upper knife is a 5 blade Cattle but what is bottom picture ? a 4 blade Jack ??
How would you define "Railsplitter" ? i have never known what it meant other than usually see a serpentine frame.
kj

The lower one is a 5 blade;here is a picture with all the blades open. You have to look really close in the original pic to see the other two blades.

[kootenay joe]

Thanks Ray. I can easily see the other 2 blades now that i know they are there. I have or maybe had, the same Sears/Camillus 5 blade Cattle knife, at least 2 examples, but used, have never seen an unused one.
kj