Most likely carbon steel. It won't rust, but it can discolor if you let acidic foods stay on it too long. So give them a quick wipe or rinse not too long after you've cut your lemons and tomatoes and you'll be fine. Check the instructions but they may tell you to avoid the dishwasher. And I recommend towel drying to keep from getting water spots, though these do come off.

Thanks. Although I have only owned the knives for a week, the instructions are long gone. Personal bad habit. Now have to fix the bad habit of letting the knives sit too long before washing them.

With carbon steel knives I keep a towel (actually an old diaper---one of the best kitchen cloths you can find, in my opinion) handy, and the blades are wiped after every use while working. Then they are washed and dried immediately.

I tell myself I should be doing that with the stainless blades as well, but am more often remiss than not.

The discoloration on my carbon steel paring knife and DW's carbon steel Chinese chef's knife comes right off with Barkeeper's Friend.

I have a few Sabatier carbon steel knives purchased in France in 1975. They're pretty ugly, but they sharpen up beautifully. When someone (no names) carelessly leaves them wet after use, I clean them up with a little thing called a "Handblock." It's a very, very, gentle abrasive block. I got it years ago at a hardware store that no longer has any recollection of having sold it. However, you can find them online, I believe.

cookie8,

You either probably have high carbon steel or high carbon stainless steel knives. There is a big difference so find out. If you have high carbon you should have noticed some discoloration by now. If it's high carbon stainless you shouldn't have.

In the absence of a patina, or some other rust protectant like oil, high carbon steel will indeed rust unless you subject it to moisture for only short periods of time and then keep it very dry. For this reason I like to have a patina on all my high carbon steel knives. It makes care a lot easier. You still have to worry about the edge though because steeling and sharpening will remove the patina.

A good patina is an excellent rust protectant. It will also make the knive blade look very dark so if you want shiny knives you can use BarKeeper's Friend and it will remove the patina but your knives will require a lot more maintenance.

In the normal course of using a knife it may take years to get a really good patina. I learned this trick for obtaining a deep patina almost instantly on a high carbon blade:

1.) Make sure the knife is VERY clean and dry.
2.) Submerge the knife blade in white wine vinegar for 10-20 minutes, or until the desired patina is achieved.
3.) Wash the knife in warm soapy water and dry immediately.