I just fired off an email to KAI USA for an official answer, but I was curious what you guys though.

My favorite daily carry has been the 0804CF, since its release. When I recently discovered that the knife had been discontinued, I jumped on picking up a spare. Because I bought my first one right when it was released, my serial numbers (probably) represent the beginning, and end, of the production run.

Here's a pic...



Note the markings indicating blade material. Is it common for this to occur over a production run?

Yes, they will change to equivalent steels through a run depending on who has the availability.

They've done it with Elmax and S35VN

They've done it with 204p, 20cv and M390.

After reading this I checked mine. My serial number is in the the 40XX range and it is still the CTS-204P.

That's not a super substantive change, either, since CTS-204P, 20CV, and M390 are all basically the same steels. I think the important thing is that they're all marked. I wouldn't want to buy knives where I knew the blades were of varying material but there was no way to tell.

Thanks, guys. Here;s the official word from ZT -

"The ZT 0804CF original had the CTS-204P steel in 2016 and then changed to CPM 20CV in 2017. It was then discontinued in 2018."

I don't know how common it is, but there is certainly nothing improper about it.

I don't think there are any knife-steel labeling requirements, either. Many do label their knives because they use the steel as a selling point. But they don't have to.

It wouldn't be right to mislabel a knife, but no label or a change in the steel used are not problems.