Surface grinding sucks

Bill Thomas

Bill Thomas

Joined
Jul 7, 2013
Messages
64
My first batch a knives were from 52100. I'm working on my second batch using 440c. I started with 60 cubetron and I don't remember it being such a arduous task taking the profile down to a 120 surface grind. Is it the 440c that is such a pain? I had a lot more scale on this stock than I remember my 52100 having. I seem to be going through a lot of belts to get a good 120 finish. Do you surface grind to 120 before heat treat? Any tips?
Thanks
Bill
 
If you don't have a dedicated surface grinder, I recommend you do all your other grinding first. Trying to surface finish the entire blank is really a pain to do well.

Bob
 
I don't have a dedicated surface grinder. I'm using a 100lb Magnate on a flat platen. I was just tring to get a more precise center line by doing the entire surface. But I think I'll take your advice and do the bevels and worry about the flats later so there is less surface to finish. Thanks
 
Try going to a 34 or thereabouts ceramic belt if you are using a finer grit. I use one similar just to remove even less than .010. It helps to keep the bar level. As well if you have bark on your steel get rid of it first by soaking in vinegar or a weak solution of ferric chloride. Frank
 
You can also get "surface ground" which means the heavy scale is off of there. Precision ground is nice, but I only get it for smaller stainless blades on which the bevels are ground after HT, since they come out pretty clean and straight.
My first time working with 440c it had that heavy scale on it, and I ended up using hand held angle grinders to chew through it- like you say, it's murder on your belts.
When you do go to mark center for the bevels, the flatter your steel is the better they'll come out.. took me a while to realize how important that is.
Next time you order, you can be sure it doesn't have that heavy scale on it.
 
Thanks for all the replies, they are very helpfull! Not that this has anything to do with surface grinding but I'll share this recent experience with you anyway. This week I was drilling thong holes and burned up two 1/4 dewalt bits on three holes. The next day I got a cheap jobber ($3.25) bit and some cutting fluid and drilled 10 thong holes with no problem. It's always good to find a solution to a problem.
 
Frank Niro said:
Try going to a 34 or thereabouts ceramic belt if you are using a finer grit. I use one similar just to remove even less than .010. It helps to keep the bar level. As well if you have bark on your steel get rid of it first by soaking in vinegar or a weak solution of ferric chloride. Frank
Click to expand...


Frank,

Do you mean a 34 grit ceramic belt?

Jantz has some really nice precision ground A2 and 0-1 that I like using. Not to bad of a price either.

Nick

Nick
 
Yes, I do mean a ceramic belt. I have a black one made by Norton but only sold in certain locations. I can buy it in Canada. It has really helped me out. I don't have a surface grinder and have been making liner locks only for the last 15 or so years. I was using 60 grit to help get me there and then lots of sanding on a granite plate. I now get close with the 36 and then go to a variable speed magnetic disc grinder. It sure helps out this old guy. Frank
 
Frank Niro said:
Yes, I do mean a ceramic belt. I have a black one made by Norton but only sold in certain locations. I can buy it in Canada. It has really helped me out. I don't have a surface grinder and have been making liner locks only for the last 15 or so years. I was using 60 grit to help get me there and then lots of sanding on a granite plate. I now get close with the 36 and then go to a variable speed magnetic disc grinder. It sure helps out this old guy. Frank
Click to expand...
Tapered disc or flat ?

Don't you do a lot of finishing on a surface block, sandpaper and elbow grease? Can you explain your process for that?

Nick
 
You can also soak your blanks in vinegar overnight and remove just about all the scale then surface grind them.
 
You must log in or register to reply here.
Back
Top