Why Is Only the Edge Rusting on This Stainless Steel Knife?

This Santoku knife combines the best of both worlds: stainless steel for rust resistance and high-carbon steel for exceptional sharpness.

Its blade has a laminated construction, with a core of high-carbon steel sandwiched between softer stainless steel. When used properly, even if the exposed carbon steel edge develops rust, the entire knife will not rust away.

The dark section visible along the edge is the high-carbon steel core. Years of repeated sharpening have gradually worn it down until very little remains.

Think of it like a pencil that has been sharpened so many times that the graphite core is almost gone, leaving mostly the wood behind. At this point, the knife can no longer perform as it was originally designed.

If you seek advice before the edge reaches this condition, simple routine maintenance at home is usually enough to keep the knife performing beautifully for many years.

For this restoration, we carefully removed some of the surrounding stainless steel to expose healthy high-carbon steel once again. The knife was successfully brought back to life.

We also restore well-used knives purchased from other stores. During our sharpening classes, we teach practical maintenance techniques so you can keep your knives in excellent condition for years to come.