How to Polish a Knife Blade

Polishing out scratches in a steel knife blade just takes some sandpaper, Simichrome, and elbow grease.  I experimented with polishing by hand and came up with some simple recommendations.

There are usually 2 obstacles to getting any task done.  Not knowing where to start and worrying about “ruining” whatever it is you are working on.  I know how to sharpen a knife with a file and with a stone.  But I have not done much cosmetic work on knives.  So I decided to venture into knife repair, and learn how to remove scratches from a knife.  I started with a badly scratched kitchen knife because I didn’t care if I ruined the way it looked.  It was just a kitchen knife, not a rare collectible Bowie.  And also, this particular kitchen knife was really messed up.  It is a Gerber Balance Plus 1401 10” Cooks knife made of high carbon stainless steel.


A knife blade that has been badly scratched

More Scratches than Blade

This knife blade is badly scratched by bad sharpening technique.

Very badly scratched blade, probably from terrible sharpening technique.

Scratches cover this Gerber Chef's Knife

Scratches Scratches Everywhere

Please note, I did not scratch the bejesus out of this knife.   I got it second hand.  It is hard for me to imagine how a kitchen knife could become so damaged.  Pretty much every bit of the blade was criss crossed with big and little scratches.  But that made it a good place to practice.

Let’s review the rules of every DIY project:
Rule #1, get started.
Rule #2, don’t ruin it.

In the spirit of getting started without ruining it, I began my knife polishing project by trying Simichrome metal polish first.  I recently discovered Simichrome polish, which is a metal polish that also works on a variety of other hard surfaces.  It does a good job at really bringing out a shine, and it is very mild.  I thought I would try the mildest polishing technique in my arsenal first because that would have the least chance of damaging my blade.

Simichrome polish for polishing metal

Simichrome Polish is great for finishing the job, but don’t be afraid to start with something a little rougher to finish the job more quickly.

Though I could not feel the scratches on the blade with my finger, it soon became obvious that the scratches were too deep for Simichrome.

My next blade polishing technique was to use sandpaper.  I started out with 400 grit sandpaper.  That too turned out to be too mild to make rapid progress.  From there I moved down to 240 grit sandpaper.  The 240 grit did a nice job of removing about 80% of the scratches.  But many of the scratches didn’t seem to be much phased.

I then started working on the knife with 150 grit.  I really thought 150 grit would be too coarse, and that it might put deep scratches of its own in the blade.  But it worked nicely.  And if I had any 100 grit, I would have given that a try to speed things along.

After working for a while with 150 grit, I then moved back up through 240 grit, 400 grit, and then up to 1500 grit.  After the sandpaper I went back to the Simichrome polish.  The result is that the knife looks much much better than it did before.

Shiny knife blade after polishing to remove scratches

This knife is much more shiny and smooth after polishing.

This knife has been polished and shined.

With most of the scratches removed, this is now a nice looking knife.

Polished knife blade reflects like a mirror.

The knife has gone from scratched embarrassment to mirror shine.

As you can see, I did not take out every scratch, mainly because I wasted so much time experimenting with added steps that I didn’t really want to back up to heavier grit and remove the last of the scratches.  But most of what remains is only visible in a very high contrast environment.  The knife looks almost new now, and I actually enjoy using it more now.  I didn’t realize that the ugliness of the blade bothered me before, but it did.

Here are my recommendations for polishing a knife blade that is badly scratched:
Don’t worry about causing more damage by using too coarse of a sandpaper.  Next time I will start the process by sanding with 100 grit sandpaper to remove the heavy damage quickly.  The way I did it, starting with the mildest, working all the way through to the roughest, and then back through to the mildest was very tiring, and ended up taking about 2 ½ hours.  Starting out with 100 grit and going up as needed would probably only take 1 hour or less.

Simichrome works well as a polish on metal and micarta.  The only problem I had was where to buy Simichrome polish?  Orchard Hardware (OSH) did not have it.  O’Reilly Auto Supply did not have it.  I finally found it at Ace Hardware, locked in a case.  The Ace guy, who uses Simichrome himself, told me that the company that makes it doesn not have a distributor, so stores need to order it directly from the manufacturer.  If your normal hardware store doesn’t have it, I would order it from Amazon (always support your local hardware store, or one day it will vanish, and your house will fall down for lack of one damn bolt on a Saturday afternoon).

Knife Polishing and Scratch Removal Supplies:
– 100 Grit Sandpaper
– 220 Grit Sandpaper
– 400 or 600 Grit Sandpaper
– 1000 to 1500 Grit Sandpaper
– Simichrome metal polish
– cloth diaper, old washcloth, or similar cloth for applying Simichrome
– disposable rubber gloves – optional but probably good to use when generating metal dust and using things like Simichrome.


  1. Can you do a video?

  2. lee holseberg says:

    As a motorcyclist since 1963, I’ve been using Semichrome for nearly 50 years. It’s always been readily available at most motorcycle shops, and works like nothing else to turn the aluminum look of brake and clutch levers into the mirror reflection of chrome. Never used it for scratch removal, seems much to fine to do the trick. Jewelers rouge in one of the numerous colors applied to a firm cloth polishing wheel on a grinder works pretty well on scratches, but stainless is a bitch to polish out no matter what you use. Good luck!

  3. Anonymous says:

    How much time do you recommend spending on each grit of sand paper? Is there some type of finish on the blade that you should look for to know when to switch to a milder grit? Thanks for this post, very helpful.

    • There are many variables in polishing a knife. The type of steel is going to influence how quickly blemishes can be removed. Hard steel is really hard to polish, and can take a lot of work. The only answer is that you need to experiment. See what works on your knife. If you can’t get a scratch out, move to coarser paper. If the blade is not getting any shinier, switch to finer paper. Let me know how it works.

  4. Did you use the polish while sanding or not till the end?

  5. A very interesting tutorial mate,
    Every knife user knows the important of keeping his knives sharp and clean though, polishing a knife is very different from sharpening but, its very important.

    Having a knife is not always the main thing, the main thing is to know how best to maintain your knives.

    Thanks for sharing.

  6. Bill McDaniel says:

    Thanks for the Post. I’ve got a Jungle knife, Phllippine Bolo Knife to be exact, that I’ve wanted to work on for years and your post gives me the courage that I need to just go do it. The knife has a great “balance” for me and I’ve used it in the jungles of SEA and know it’s worth keeping as a memento and a work horse.

  7. malcolm says:

    Hallo my grandfather made his own carving knife from stainless steel but he cant get the deep scrathes out and we tried to do it your way but failed any other ideas?

  8. I always wonder how people scratch up their knives this much. In any case you did a damn good job, never heard of simichrome before- I assume its like Brasso for steel?

  9. you are correct on the sandpaper method. normally if there are no scratches, 220 is fine – the main thing is to get out the pits, scratches, and grind lines. That example was bad, so 100-150 is good. It depends on the knife, but here are a few examples of what i have done with a few. A normal new knife from say spyderco, i just went right to the buffer – you can see the results on the photo bucket link posted. The same can go with an already mirror polished blade, like the shun in the pics i’m working on now (may need to sand it but haven’t started it yet so idk).
    However those are powder steels, and you will get a great nice mirror not perfect with just a belt grinder buffing wheel set and compound set. On a harder steel or carbon blade like a cold steel trail master here is what i do – btw on ebay you can buy packs of all the grits for a lot cheaper.
    Use a small piece of wood, and glue an old piece of leather from a belt or strop, on it to the exact same size. only make it like the size of your pointer finger but wider. This will give it some give, so it rides the convex nature of the natural grind, but allow you to take out what you don’t want the above things. Also, when sanding by hand it will create a slurry, clean that off when changing grits, but leave it on when on the same one, it helps to smooth things out even better!
    So, on say a busse or CS TM – i would start with wet always and go 220, 300, 400, 600,800, 1k, 1500k, 2k, 2500k, 3k, and then 5k. It will look satin finish at about 1,500 and almost or mirror at 3-5k.
    Then after the sanding, keeping in mind as you go toward the finer grits of 1k and more, use a lot less pressure, and allow the sandpaper to smooth over the scratches, and pours of the steel.
    After that, i take it to the buffer. You can use 2 or 3 wheels for this part. Use a harder wheel and start with emery, or yellow/green, and finish with a soft wheel with white jewelers rouge.
    After all of that, it will be a perfect mirror. Next just sharpen the same way, moving from 220-5k, strop and you are done!! But do not go too low on the sharpening, and scratch your awesome mirror finish, it is easier to do than you think. It takes about 1 day for the sanding, and another for the sharpening, maybe 2 for the sharpening, and like 1 or 2 for the buffing, depending on where you stopped.
    My project now is tricky, as the blade is already mirror polished, but has some pits and surface scratches, and some minor pitting – it also has a really nice logo. I recommend regular micro fiber tape for the logo and handles if its full tang. If the handle needs a buff, just using the light wheel with white rouge will be fine to mirror the rivets. The back pommel will need all 3 wheels maybe.
    The main thing will be the logos. I usually tape those and dance around them and just buff. However, you can acid etch any logo you want back onto a blade, but it will not be factory perfect!!
    So what i plan to do is buff everything, and then lightly go over the logos with the soft wheel and white rouge. this will blend everything back together and the whole knife will look awesome. If some of the paint comes off, it can be gently repainted, or if its too bad, a new acid etch and painting will need to be done. Thanks mike, hope that helps and i hope this new project goes well!

  10. Also, a great when everything is done polish is flitz, its even better than that other kind imo. But its just for cleaning off any black stuff left behind, and getting to that perfect mirror and cleaning. After that, i usually use tuf glide to oil the knife, before selling or putting it away!! thanks again mike

  11. if you can’t find that polish, flitz will work the same!!

  12. I followed your recommendations and I’m amazed with the results! I did it on an old kitchen knife that I value very much.
    The only different thing I did was using Brasso instead of Simichrome due to availability.
    Thanks a lot!

  13. THANK YOU!!!

    Searching for a missing knife (think it went to San Francisco with the former roommate…), I realized most of my knives are shamefully scratched up, thanks to long-ago amateur attempts at sharpening on the stone my father left after he passed. (As an aside: when you don’t know what you’re doing, don’t. 😉 )

    When I came across your post, I thought, “I wonder what this would actually do?” In the garage I managed to unearth 120, 220, and 320 grit sandpaper and decided to test your strategy on a boning knife that I do value but whose destruction will not end my life. Used Barkeeper’s Helper to polish.

    Darned it if didn’t work! The knife isn’t perfect (yet), but it’s a long sight better than it was. The knife had to be resharpened (these days I use one of those Wusthof manual sharpeners, which keeps a nice edge on the kitchen knives and doesn’t ding them up). The result was a far more aesthetically pleasing knife.

    When I’m up in the direction of the Ace, I’ll buy the sandpaper grades you recommend and go to work on the rest of the cutlery. Also found some grade 0000 steel wool out in the garage. I’ll bet this would also be good for the polishing phase. Don’t know if our Ace carries the Simichrome, but there’s a Harley shop right up the road — many thanks, too, to the reader who pointed out its popularity among bikers.

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