Do You Line Your Bucket Or Replace The Bottom?

This CAT 349E Excavator bucket shows extreme wear areas after less than 8 months in service. These waves in the bucket floor are because the steel is not the same hardness all the way through.


The waves appearing in the bottom of this nearly new 5-yard bucket, are from using AR400 that is not the same hardness thru the steel thickness.

What causes this wearing wave pattern? The hard outer surface of the steel has worn through in some areas. This exposes the softer center thickness of the steel plate. The center of most AR steels is much softer than the top and bottom surfaces.

Once the softer center is exposed to the material as you dig, it starts wearing rapidly. The wave appearance now begins to show accelerated wear from the inside out.

This creates a situation where you see the steel wearing quickly. It looked like brand new for a period of time. Then two weeks later, the material looks so worn people often wonder what did we get into that was so hard last couple weeks? The material was exactly the same, but your bucket exposed the lack of hardness in the steel.

We call this phenomenon, the Oreo® cookie effect.
Because all steel is hard to the touch, this often sounds strange and confusing to most people.

Without having the correct alloying elements, in the proper ratios, the steel cannot become hard throughout the thickness of the steel. In reality, the steel surface develops hardness only about 0.030” deep.

This means the hardness at the center of your wear plate is nearly the same as mild steel; between 120 to 180 BHN. And the heavier your plate, the more pronounced is this Oreo cookie effect.


Most wear plate acts like an Oreo® cookie – harder on the outside and much softer in the center of the steel plate.

If you have ever seen wear resistant steel look fine, & suddenly it is almost totally gone, this is exactly what has happened. The center of the steel was much softer than the face. This is exactly what it looks like.

Making wear resistant steel the same hardness all the way through the thickness of the steel is developed with the addition of Nickel, Chromium, Moly and Boron.

Your benefit in using through hardened steel is the even, progressive wear throughout the thickness of the steel.
This allows you to monitor the wear; allowing you to control when to replace the steel. Finally you can determine when it is convenient for your schedule, rather than reacting to yet another breakdown.

How do you combat wear in your bucket floor?

1. Do you put in a wear liner to extend the bucket’s life?

2. Or do you replace the bottom?

With a liner, you often have a lower initial material cost because a liner is thinner than a replacement bottom.

Remember, you already have wear on the bucket. This means what remains at this point is thinner than when the bucket was new.

The purpose of an excavator or a loader bucket is to pry material from the earth. When you wear a hole through the original base metal, fine materials become forced between the bottom and liner.

Realize you are scraping material at very high pressure and packing the material between the new liner and the old base metal.

This serves to continually force more material between the two layers. If your liner is thicker than the remaining bottom on the excavator bucket, what happens is the thin worn exterior base metal becomes forced out and does not remain flat.

This creates hydraulic pressure that will create bulges on the thinner bottom. It can also crack the welds holding your new liner in place, to the point where it may break loose causing even more downtime.

This delivers unacceptable results when excavating a building foundation. Rather than the straight blade of the bucket creating the flat, even foundation plane; now you have to deal with scallops and an uneven surface.

Replacing the bottom after you have worn out your liner, you have to remove both pieces of steel. You will discover the packed sand does not cut away with a torch.

As the gasses escape when you're melting the steel, the moisture from the sand pops and spits. This is a safety hazard as it creates mini explosions, erupting the molten metal all over the worker and the area.

It requires additional labor to remove the liner then remove the base metal in order to install your new replacement bottom.

If you're going to be keeping your equipment for a longer period of time, the smart play is to install a new replacement bottom JADCO’s QT Plus ® that is the same hardness throughout the steel.

Why not invite a JADCO sales professional to review your excavator or loader bucket? We understand what you are doing, so we can help you make real improvements in your equipment; literally for the long haul.

Contact your local JADCO professional by calling us at (724) 452-5252 or email us at:

We look forward to helping you get control of your bucket wear issues.