Blanchard Ground vs Precision Ground + other questions on steel

G

GrizzlyBear

Joined
Dec 5, 2009
Messages
1,528
I was perusing sites this morning for steel (Jantz, TKS, Alpha, Aldo's site, Niagra, etc). Just looking at prices and what not.

I've noticed several "versions" of steel that affect price and I'm curious on what a stock removal maker should get.

Jantz has blanchard ground and precision ground...what are the differences?

Other sites, Niagra in this case, has steels that are saw cut and shear cut...belt ground or simply descaled.

I just noticed that these variances can drastically change the pricing...can anyone give me a little info?

Thanks!
 
Precision ground means it is surface grinded flat.

From what I gather there is steel which is not precision ground and then there is steel that is. Us as stock removal makers can use either, though precision ground saves some time since it is already flat. If you get non precision ground you need to grind it flat yourself. I have gotten some advice on doing this with a welders magnet on the sander though I still don't understand how exactly. I have a big bar of steel waiting to be made knives once I figure out how to get it flat.
 
Not too sure on blanchard ground a quick google search says it involves grinding the surface of the material with a grinding wheel on a vertical chuck. I take this to mean it is similar to face milling, just on a larger scale... but precision ground will definitely be your most expensive. It means your steel will come with a uniform thickness, no scale (smooth ground surface), straight and squared along the edges.

I think it's up to preference and how much prep you want to put into your steel before working with it. PG makes the most sense for me because I don't have the proper tools to surface grind or square stock effectively. It costs a bit more, but I also start off with a piece of steel that is 100% ready to be cut out and ground on.

Edit: Blandies, using a welders magnet on a belt sander is another way to "surface grind" the poor mans way. I do this to knock off burrs from drilling my stock... I just tape over the face of the magnet, attach the blade flat and parallel to the magnets face and hold it down on my 4x36s platen. As long as you are careful and put it down flat, you won't encounter too many issues with rounding off the tip or butt of your profiled blade. If you are planning to grind off mill scale though I'd suggest soaking in vinegar overnight though... scale eats belts. Jonnymac does this: http://www.bladeforums.com/forums/showthread.php/828239-WIP-Starting-a-new-batch-all-D2-Updated-4-25-11-New-Progress?p=9377730#post9377730 6th picture in that post :thumbup:
 
Last edited:
wolffbite said:
Not too sure on blanchard ground a quick google search says it involves grinding the surface of the material with a grinding wheel on a vertical chuck. I take this to mean it is similar to face milling, just on a larger scale... :
Click to expand...


Thats pretty much exactly what it is, picture it as a few stones rotating in a circular motion over the stock held in palce on a magnetic chuck. Blachard grinding is for quick and heavy stock removal. Unlike conventional surface grinding which can leave a nice finish at a precision thickness.


Shawn
 
I thought I read somewhere that Blanchard ground is actually more precise than surface ground

I use rolled annealed because I'm just gonna heat it up and bash it with a hammer anyways
 
wolffbite said:
Edit: Blandies, using a welders magnet on a belt sander is another way to "surface grind" the poor mans way. I do this to knock off burrs from drilling my stock... I just tape over the face of the magnet, attach the blade flat and parallel to the magnets face and hold it down on my 4x36s platen. As long as you are careful and put it down flat, you won't encounter too many issues with rounding off the tip or butt of your profiled blade. If you are planning to grind off mill scale though I'd suggest soaking in vinegar overnight though... scale eats belts. Jonnymac does this: http://www.bladeforums.com/forums/showthread.php/828239-WIP-Starting-a-new-batch-all-D2-Updated-4-25-11-New-Progress?p=9377730#post9377730 6th picture in that post :thumbup:
Click to expand...

This is why I like to clarify on things I'm not 100% sure about,which may come off as me ignoring advice but I may be making mistakes that lead to safety problems. From what I gathered you put a huge welders magnet on the very back of the platen and put the knife on the front of the belt and the magnet goes through the platen and everything in between all the way to the knife and holds it in place...in other words you could just turn the sander on and walk away while the knife is getting ground.
I didn't think that sounded right so I'm glad you cleared that up for me. Pictures are worth 1000 words.
 
stephanfowler said:
I thought I read somewhere that Blanchard ground is actually more precise than surface ground

I use rolled annealed because I'm just gonna heat it up and bash it with a hammer anyways
Click to expand...

A quick search revealed just that... it can be more precise. I had some stuff blanchard ground and was just relaying what the shop told me. See that I dont post in like a year and m allready spewing misinformation.

Shawn
 
From what I gathered you put a huge welders magnet on the very back of the platen
Click to expand...

I'm no expert, but envisioning what you are describing is terrifying me.

In my experience, the magnet attaches to the knife stock, and you press the exposed side of the stock against the moving belt.

The stack of components could be viewed as:
platen->belt->steel/knife->tape->magnet

I'm not certain why the tape is necessary unless you're trying to protect an already fancified surface, but by that time you're usually done with the flattening anyway and are just doing finish work.

-Daizee
 
I have used both for surfacing my damascus.
Surface grinding is usually more precise, and with a finer finish and usually guarenteed flat. It is also labor intensive and therefore expensive.
Blanchard grinding is a bit less precise, holding tolerances to .001" with a surface finish close to that of a 60 grit belt. It is done on larger machine so more can be done at one time. The magnets on a blanchard grinder are huge and powerful. The stock is usually guarnteed to have paralell faces, but not always perfectly flat, because the magnets pull the stock flat and it snaps back after the magnet is off. This is not common, but I have run across a few pieces and a minute or two of tweeking in the vise and they are flat.

Saw cut steel will have nice precise cut edges, shearing will not be as clean and the ends may be slightly bent.
Del
 
daizee said:
I'm no expert, but envisioning what you are describing is terrifying me.
Click to expand...

See? Good thing I like to be 110% sure on things! I've never been tool savvy or brought up around them,everything I'm learning each tool and operation is something new I have to learn. 20 years of my life raised with city folk....this is what I get!
 
I don't buy precision ground or blanchard ground, but it can save you some belts. On ats-34 and CPM-154CM, the scale can eat belts pretty fast.
 
Whether precision ground or blanchard ground in order to keep the stock flat the same amount of material must be removed from both sides. That darn residual stress. :thumbdn:
 
Whatever the method, the ability to start with a flat piece of steel is worth the cost.
 
So as a beginner knife making enthusiast with not a lot of tools I should opt for the precision ground??
 
Of course. Else you will be sitting on the couch with your finished blank, fondling it and suddenly notice it has dips and bumps in the reflection. Then you will run to the grinder trying to get it flat and screw up your left to right centering and most of all the bevel grind lines.
 
Last edited:
Okay cool, thankyou very much, I'm still waiting on goddards $50 knife book to arrive so hopefully that will help answer a lot of my questions
 
Cubroast said:
So as a beginner knife making enthusiast with not a lot of tools I should opt for the precision ground??
Click to expand...

Depends on what you're doing and now hard the mill scale is on the unground stock. I flat grind (and have a KMG) so the only part of a fixed blade knife where the precision ground helps is the ricasso. That still requires significant hand finishing with precision ground because it starts out flat and parallel but not with a fine grit finish.

The AEB-L and 52100 I get have light scale that is easily removed as part of the grinding and cost a lot less. I still get A2 as precision ground because that's what's available but it's a good deal more expensive. On the other hand, the very thin (.048) 3V I got a while ago had really hard, stubborn scale that was a real pain to remove. I probably won't work with it again.
 
Cubroast said:
Okay cool, thankyou very much, I'm still waiting on goddards $50 knife book to arrive so hopefully that will help answer a lot of my questions
Click to expand...

If you are using files, you flatten your stock by draw filing. It is difficult to flatten stock with a belt grinder. I enjoyed Wayne Goddard's books. A lot will depend on which direction you decide to go with your knife making on how useful it will be for you.
 
Blanchard ground can be just as flat and precise as surface grinding. I spent 2 years on one. A good operatror can get them smack dead on!!! A blanchard grinder has a rotary table that spins and a circular grinding wheel is brought down on the part. Ever seen the swirl marks in big plates then youve seen what a Blanchard grinder can do. Blanchard grinders are typically used on larger plates and Id assume strips of material for knives would be cout out of the larger plate.

Jay
 
You must log in or register to reply here.
Back
Top