Correct selection of belts for various knife making and sharpening purposes

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kevinmacdonald

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I bought a Burr King 960-272 knife grinder several years ago, but never quite kicked off my custom knife making endeavors as yet. I have all or most of the belt types below. Does anyone have informed opinions on what purposes they might apply these belts to? For starters, what's the best belt for sharpening existing kitchen knives? Would you go for the very finest grit? Or perhaps I am missing one or more designations I should have in my set?

2 x 72 - 50 XK760X Ceramic
2 x 72 - 120 XK760X Ceramic
2 x 72 - 220 707JE Regalite Ceramic
2 x 72 - 320 RB346MJ Aluminum Oxide
2 x 72 - 400 347FC A45CF Trizact Aluminum Oxide
2 x 72 - 600 347FC A30 Trizact Aluminum Oxide
2 x 72 - 320 X45 U254 Norax Pyramid Aluminum Oxide
2 x 72 - 600 X30 U254 Norax Pyramid Aluminum Oxide
2 x 72 - 800 X22 U254 Norax Pyramid Aluminum Oxide
2 x 72 - 1200 X16 U254 Norax Pyramid Aluminum Oxide

The Burr King has very fine variable speed control. I'd also like to figure out appropriate speeds for different purposes.

Thanks for any tips.
 
For general grinding, you really don't need all those steps. A good rule of thumb is to double your grit for each step.

So maybe a good progression would be 36, 80, 120, 220, 400, 800.

But really going above 400 on the belt grind is probably a waste of time, and certainly a pretty high risk of generating way to much to heat.

Anyway just my opinion!
 
I don't suggest sharpening any knives on your 2x72 unless you have water coolant, angle control, and experience. Powered sharpening can easily affect the temper of your blade.

I use 36 grit for profiling and hogging. 50 grit is good to clean up and get most of the bevel. You can start at 50 on small knives. I'll go to 120 ceramic, then a flexible 120 to smooth the bevels and clean the plunges. I rarely go past 120 on the grinder, so from there it's hand sanding.

The more skill you have, the higher you can go on the grinder. Folks generally dial back the speed the higher the grit. At 50 grit, you want pretty high speed and a light touch.

There's a difference between using a 220 grit belt for a few minutes, and achieving a truly clean 220 finish. When I hand sand after 120, I still often find some 50 grit scratches under there.

In short, I'd put aside all but the first two you listed for now. Everyone does things differently, so I'm sure you'll get some completely different opinions.
 
Regalite are nice for cleaning the plunge cut. They cut well and form to the corner of the platen.

347FC can be used wet, no question or debate. They don’t like single point grinding (drill bit sharpening for example), work better when grinding across a wide area.

Beware of grit numbering vs trizact numbering.
K

Thread 'The Grand Unified Grit Chart'

EDIT: Since creating this chart, it has gone through many revisions and has become far too unwieldy to keep saving as a JPG. Mainly, because it won't fit on one *screen* any more. So, the latest version will now be kept HERE!

Well, I've seen a lot of charts comparing various grit sizes in different systems out there, and at the behest of a friend on another forum, I've started somewhat of an ongoing project. None of this data is mine, it has been compiled from internet sources, and cross-checked where possible. If you spot an error, or have additional data that...
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I started out using those Norax U254 belts, don’t rate them. Cannot be used wet, glaze and lose cut. I do use cork belts with green chrome up to 800 grit, but would not mess with those Norax beyond 400.

I would possibly use all of the belts for sharpening kitchen knives, except for the 50, but which and how would depend on the knife and what was needed. Edge thinning and blending can be done on a belt and the blending can be good with finer grit. Resetting the edges on very blunt knives can be done with 120. I unwisely offered to sharpen a work colleague’s kitchen knives, he said he had “good” knives, but the were 420 rubbish with edges so rounded that there was little to choose between spine and “edge”. I attacked some with a 60 grit just to save time.
 
Richard338 said:
I don't suggest sharpening any knives on your 2x72 unless you have water coolant, angle control, and experience. Powered sharpening can easily affect the temper of your blade.

I use 36 grit for profiling and hogging. 50 grit is good to clean up and get most of the bevel. You can start at 50 on small knives. I'll go to 120 ceramic, then a flexible 120 to smooth the bevels and clean the plunges. I rarely go past 120 on the grinder, so from there it's hand sanding.

The more skill you have, the higher you can go on the grinder. Folks generally dial back the speed the higher the grit. At 50 grit, you want pretty high speed and a light touch.

There's a difference between using a 220 grit belt for a few minutes, and achieving a truly clean 220 finish. When I hand sand after 120, I still often find some 50 grit scratches under there.

In short, I'd put aside all but the first two you listed for now. Everyone does things differently, so I'm sure you'll get some completely different opinions.
Click to expand...
I'm originally a machinist, and I have a fairly well equipped shop. Retired now. Knife making could become a hobby. I'm in a great position to make my own precision fixtures for angle control etc. And I have a lot of experience sharpening tool bits for machining operations. So my next questions are going to be about what I need to get started in knife making! I have a small forge and anvil and I've hammered out a simple blade from high carbon steel. But I'd like to figure out what I really need for proper hardening and tempering. I don't know that my forge is well suited for it. It produces very uneven temperature. Do I need a kiln? Do I need a container for oil quenching? I won't be doing any this at a professional scale. Just making gifts for people.

Regarding fixtures, since I have my Burr King 290-272 I imagine I will make grinding/sharpening fixtures designed specifically for it.
 
The list of what you might buy is very long. The list of what you absolutely need is not long at all. Sending blades out for HT is what most new hobby makers do.
You are correct in thinking that a forge is a very uncontrolled HT method compared to a kiln. However, millions of knives have been HTed in a forge.
A forge is nice, but forging still requires final shaping and finishing. Forging vs stock removal is a constant debate, but forging is not necessary for making knives.
A grinder is very nice, but files and sandpaper work fine, too.
A HT kiln is very nice to have, but a couple grand will HT al lot of knives. Most hobby makers never make enough knives to outweigh the cost of a kiln.


In usually recommend people don't buy a lot of specialty tools until they make and finish about 10 knives with simple tools. If it still appeals to them, spend the money. Finding a maker in your area can greatly bhelp you get started and provide access to good equipment before buying what you may not want or need

Most folks use a list like this, in order of purchasing priority:
Good known type and source steel
Hand tools, files, lots of sandpaper
high-tension hacksaw with Lenox blades
Angle grinder with cut off discs
Drill press
Belt grinder (you can start out with a cheap 1X30, but eventually you will want a 2X72)
Portaband saw and SWAG table
A forge, hammer(s), tongs, and anvil (you only need these if you plan on forging knives - none are necessary for stock removal)
HT oven
Kool-Mist clone
Welder (MIG or TIG or stick ... whatever is in your skills) You can get away with a $90 HF welder or use a $3000 Miller Multimatic welder ... both will weld a bar on a billet or a stub tang on a blade.
From here it goes crazy - so many things and so little money
 
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As for the belts - Get a starter set and learn to use them. Then decide if you need any other sizes/types.

2 x 72 - 50 XK760X Ceramic -4pcs
2 x 72 - 120 XK760X Ceramic -4pcs
2 x 72 - 220 707JE Regalite Ceramic -6pcs
2 x 72 - 400 347FC A45CF Trizact Aluminum Oxide -6pcs
2 x 72 - 600 347FC A30 Trizact Aluminum Oxide - 3pcs
A good grade wet-or-dry sandpaper like Regalite or Rynowet - 10 sheets each of 220, 400, 800, 1200


After you get the knack of grinding and hand finishing down (10-20 knives) .... add three pieces each of these
2 x 72 - 320 RB346MJ Aluminum Oxide
2 x 72 - 320 X45 U254 Norax Pyramid Aluminum Oxide
2 x 72 - 600 X30 U254 Norax Pyramid Aluminum Oxide
2 x 72 - 800 X22 U254 Norax Pyramid Aluminum Oxide
3-M flexible polishing papers (400-8000 grit set)
 
I like a 50 grit ceramic for primary bevels, and finish up at 220 prior to heat treatment. I like 36 grit ceramic for initial profiling. I like 200 for secondary bevels, and go straight to bench stones from there. If I'm hand finishing the steel, I'll finish at 320 on the machine apres h/t, and start hand sanding at 220 or 320 if I can get away with it. If I'm leaving the machine finish, I've often finished up with a 600 or 800 Illumeron
 
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