Grinding Bevels and Flats

William Schrade

William Schrade

Joined
Jul 30, 2012
Messages
632
Good Morning Guys,

I just bought a cream puff Boyer Schultz surface grinder. It sat in a shop unused for 12 years and runs like a top.

My question is grinding the bevels or flats last.

How do y'all do it.

Thanks
 
It will be interesting this thread - I don't have a surface grinder, and was not aware anyone using a surface grinder to grind bevels on blades. Allow me to think a bit here about process if a person decided to grind bevels.

Would you not grind flat first to get final thickness and both sides perfectly parallel for first step. This would allow scribing center line for edge. If you ground bevels first, then ground flats, what if it took more material removed to clean up on one side than other - wouldn't this put the edge off center?

While bevels could be ground first, allowing enough metal to make sure both sides cleaned up good leaving edge in center, it just seems simpler to grind bevel last.

Looking forward to an educational thread.

Ken H>
 
Hi Ken,

I only grind flats with the surface grinder. And yes I grind flats first to make them parallel then grind bevels. My question was geared more toward post HT. I should have clarified that.

I used to grind flats by hand on flat platen and would sometimes wash out the grind lines. It's still easy to do when grinding bevels last.

Thanks
Bill
 
I don't have a surface grinder yet but I rough grind my bevels before HT. Then post HT I finish the flats completely and then grind my bevels. This helps me to keep my grind line crisp.
 
Get the flats first.

Then do the bevels

You want to start off with a constant to refer to and that is the ricasso.

If you grind gets wonky at the top of the plunge line you then go back and touch up the flats and try again :)
 
Bill, I think I understand your OP a bit better now. For some reason I was thinking you were talking about taking a "rough" bar of steel of steel and completely grinding on surface grinder.

I do the flats first, then hand grind bevels, then I usually wind up going between flats 'n bevel a couple of times to "clean up" grind lines. Not removing any metal to speak of, just "cleaning" up.

I envy your surface grinder.

Ken H>
 
William Schrade said:
You can't. I only grind the flats on the SG and bevels freehand. I was just wondering how others chase the grind line between bevels and flats.
Click to expand...

"Can't" seems like a challenge? lol... i have thought about this as well when i had the chance to pick up a surface grinder second hand at one point but lost out to someone quicker on the draw. In my head there seems to be a way to do it if you make a jig for your blade and run it that way. I think you "may" be able to if you do it right... could be wrong.
 
Food for thought and a little off topic but you "can" grind bevels in with a surface grinder or mill. Takes a little trig and or shims but very doable.
 
Ok, now i get it! :)
I would start with the flats on the SG to have a sound reference, then grind the bevels, and if the bevels are well done and regular (some passage on the disk grinder helps a lot), another quick touch of the flats on the SG will definitely make that line crisp!!

Tin.man: you can mill the bevels, though they are seldom flat in a nice blade geometry...ask Nathan (the machinist) about helical surfaces ;) On the other hand a surface grinder is supposed to do shallow and precise surface work, if there is something resembling bulk removal the SG is not the spot on machine to be used...not that anyone can't do his experiments of course :)
 
On the other hand a surface grinder is supposed to do shallow and precise surface work, if there is something resembling bulk removal the SG is not the spot on machine to be used
Click to expand...

That's exactly what I have used surface grinders for back so many years ago it's hard to remember. I worked in a machine shop where one of my jobs was using a surface grinder. They are "precision grinders", not "stock removal" grinders.

Ken H>
 
For fixed blades, I surface grind after heat treating then grind in the bevels to completion. On folders, I thickness the blade to within .020" of finished spec before HT using a belt on my SG. After HT, I bring the blade to finished thickness using a vitrified stone wheel then grind my bevels.

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