Quantcast

Cutting knife blanks from a sheet

Kitchen Knife Forums

Help Support Kitchen Knife Forums:

Marko Tsourkan

Senior Member
Joined
Mar 1, 2011
Messages
4,964
Reaction score
29
How do you guys go about cutting knife blanks (for stock removal) from a sheet? I have a Milwaukee Deep Cut portable band saw that I am to use for some cutting, but I don't think it will allow me to cut a strip from a sheet.

If using an angle grinder with a cutoff wheel, does the cut generate a lot of heat so that might affect the straightness of the blank? The steel I have is oversize 5/32 52100. Pretty thick stuff.

Thanks,

Marko
 

El Pescador

Engorged Member
Founding Member
Joined
Mar 2, 2011
Messages
2,225
Reaction score
1
Never cut knife blanks but angle grinder with the hose running on the sheet gets me through 3/8 plate just fine...just know that you go through discs faster than you can change them.

Pesky
 

SpikeC

Senior Member
Joined
Mar 1, 2011
Messages
3,717
Reaction score
2
Diamond coated discs are available for angle grinders, I wonder how one of those would work?
 

Bill T

Impressively pointed
Joined
Apr 11, 2011
Messages
34
Reaction score
0
It's tedious , but drilling holes then playing connect the dots works for some .
 

El Pescador

Engorged Member
Founding Member
Joined
Mar 2, 2011
Messages
2,225
Reaction score
1
Duct tape the end of the hose so the water runs across the sheet of steel. I set this up outside clamped to a table. Use a carbide cutting wheel. This isn't something I do very often. Most of the time just the wheel w/o the water.

Pesky
 

l r harner

Banned
Joined
Mar 6, 2011
Messages
548
Reaction score
0
i had a little HF 4x6 saw and killed it then got a clark 4x6 (they are all about the same) after finding a new way to brake that saw i bucked up and found a used roll n saw
800LB of killer band saw with self feed
 

El Pescador

Engorged Member
Founding Member
Joined
Mar 2, 2011
Messages
2,225
Reaction score
1
Water and electricity don't mix...unless you're kinda stupid like me! The big thing is you're not cutting through a stream of water...you're using it as heat sink close to the cut.

Pesky
 

Marko Tsourkan

Senior Member
Joined
Mar 1, 2011
Messages
4,964
Reaction score
29
i had a little HF 4x6 saw and killed it then got a clark 4x6 (they are all about the same) after finding a new way to brake that saw i bucked up and found a used roll n saw
800LB of killer band saw with self feed
Yeah, I would love to get a rollnsaw, but not in the plans for a while. So, angle grinder with a cutoff wheel and clean up on a Milwaukee hand held band saw.

:)
 

Delbert Ealy

Founding Member
Joined
Feb 28, 2011
Messages
1,152
Reaction score
0
I don't,
Now I know that may not sound very helpful, but I just don't buy stock larger than I can cut with the tools I already have. I don't buy plate, I buy strip. The only real reason to buy plate is for waterjet cutting blanks, where the cost/benifit is on your side. On the other hand, if you got the material at substantial savings or it was the only way to get that thickness, than I understand. In that case, find a local fab shop with a shear. Tell them what you need and if they can do it. Shear to a width that you can cut blanks out of and you are all set. In a pinch call Aldo Bruno, I think he has a shear that can handle that stuff.
Del
 

watercrawl

Well-Known Member
Joined
May 4, 2011
Messages
199
Reaction score
0
I have a HF 4x6 that cost me all of $180 with their sale and a coupon. You can set it vertically and put a work table on it turning it into a vertical band saw which is something not really clear or at least wasn't to me until I saw one in the store. Works good, but cutting metal with a bandsaw is tediously slow. An angle grinder is faster but not nearly as accurate and throws sparks all over the place and makes the steel red hot and throws tiny shards of steel all over and is generally far more not good IMHO. I started with the angle grinder, but quickly bought the metal cutting bandsaw and am far happier with it.
 

Marko Tsourkan

Senior Member
Joined
Mar 1, 2011
Messages
4,964
Reaction score
29
...In a pinch call Aldo Bruno, I think he has a shear that can handle that stuff.
Del
Damn, that is where I go the steel from. Should have asked him to shear it.

Is there any risk to cut the blank with a grinder? Heat build up, warping, etc?

Any of you guys use Milwaukee hand held band saw mounted vertically? I think I saw it in Stefan's video.
I have one but need to build a custom table for it.

M
 

watercrawl

Well-Known Member
Joined
May 4, 2011
Messages
199
Reaction score
0
There is a guy that makes stands for the Milwaukee band saw that look real nice and aren't too spendy.
 

RRLOVER

Senior Member
Joined
Mar 10, 2011
Messages
1,137
Reaction score
10
I have an angle grinder in my right hand and a spray bottle to keep things cool in my left hand.A welding jacket is a must unless you want to put holes in your cloths.
 

watercrawl

Well-Known Member
Joined
May 4, 2011
Messages
199
Reaction score
0
I have an angle grinder in my right hand and a spray bottle to keep things cool in my left hand.A welding jacket is a must unless you want to put holes in your cloths.
Speaking of that kind of thing, I don't wear anything but cotton when I'm working with things that make sparks.
 

Marko Tsourkan

Senior Member
Joined
Mar 1, 2011
Messages
4,964
Reaction score
29
Speaking of that kind of thing, I don't wear anything but cotton when I'm working with things that make sparks.
I have a 46" welder's leather apron (inspired by Bob Kramer video, though he has a blacksmith apron :) ). It comes very handy in metal working as well as wood working.

I am mostly concerned about whether I need to normalize steel after cutting out the blank.This is a thick steel, so there will be heat created by cutting and possible warping.

Looks pretty good (the table for Milwaukee) Adam. I might get one after all.

M
 

JohnnyChance

Founding Member
Joined
Feb 28, 2011
Messages
3,418
Reaction score
14
Cutting strips with a shear is more likely to give you warping than any angle grinder could produce.
Not a giant stomp shear. Handheld shears on thin sheet metal yes, but a stomp shear or break will cut them cleanly.
 

Michael Rader

Banned
Joined
Apr 14, 2011
Messages
285
Reaction score
0
Know anyone with a plasma cutter? Cut it 3/16" over-sized and grind out the heated zone. Shouldn't warp much. Plan on doing more of these? Definitely water/laser cut next time. Or get your own Plasma cutter. I use mine a lot.
-M
 

JohnnyChance

Founding Member
Joined
Feb 28, 2011
Messages
3,418
Reaction score
14
I dont have a plasma, just a torch. Much bigger heated zone I am sure. But 5/32" is pretty thin, it would cut pretty quick.

2 saw horses, a couple of clamps, and a sawzall?
 

Rottman

Hobbyist Craftsman
Joined
Feb 28, 2011
Messages
355
Reaction score
0
Not a giant stomp shear. Handheld shears on thin sheet metal yes, but a stomp shear or break will cut them cleanly.
I was talking about a stomp shear. It will cut cleanly but thinner strips tend to corkscrew.
 

l r harner

Banned
Joined
Mar 6, 2011
Messages
548
Reaction score
0
if you shear cpm steels at room temp you risk shattering the sheet (ask aldo about that or carpenter for that matter)

sawzalls seem to move the blade too fast for a a nice cut and blade life is jsut plain bad

safest way tho a bit slow depending on the settings is that little 4x6 tupe saw witha big thick table put o it and a seat in the vice part you jsut have to know how to mark the steel so as to deal with ath only 4 inch wide max cut

i did get lucky and picked up my "new" saw used and for about half price (USA built tools are not cheap)
 

Marko Tsourkan

Senior Member
Joined
Mar 1, 2011
Messages
4,964
Reaction score
29
Thanks everybody. Just one more question.
If there is warping after cutting steel with an angle grinder, can it be straightened by hand (and later ground flat after HT), or other steps are required to relieve stress before HT.

M
 

rockbox

Senior Member
Joined
Mar 1, 2011
Messages
395
Reaction score
2
I use an angle grinder now. It does create a lot of sparks but I have no problems with warping. Heat is not a problem since you are going to heat treat afterwards anyway. However I was thinking of using a jig saw or a reciprocating saw. Jigsaw would be better since I could actually steer the it.

[video=youtube;fWpHzf1I0BI]http://www.youtube.com/watch?v=fWpHzf1I0BI[/video]
 

Marko Tsourkan

Senior Member
Joined
Mar 1, 2011
Messages
4,964
Reaction score
29
Sparks don't bother me as much, my concern is warping that needs to be dealt with through stress relieving, hand straightening, or grinding off.

M
 

PierreRodrigue

Founding Member
Joined
Mar 1, 2011
Messages
1,847
Reaction score
1
An angle grinder, with a good quality thin zip wheel, leave a wheels width of metal outside your scribe lines, and finish grind to profileafter. On thicher material, I make a few passes along the length of the cut so as not to go full thickness on the first pass. never had any warping, and never had any issues with the heat generated. Very rare to see the steel turn red if you make a couple light passes. I started buying sheets because no matter who cuts it, they want to add cost. I ordered the last sheet from Aldo. the sheet is nice because you can "nest" a few different patterns when laying them out to reduce a large percentage of the wast associated with buying strips of set widths.
 

Marko Tsourkan

Senior Member
Joined
Mar 1, 2011
Messages
4,964
Reaction score
29
Hi Pierre,
I think I have seen your name and a phone # on a sticky pad in Aldo's office. I was wondering if it was you.

I have an angle grinder with a cutoff wheel, so this is how I will proceed for now. No plans for plasma cutter at the moment, have other priorities. Water jet blanking sounds interesting, but I have no companies (that I know of) in the area and schlepping back to NJ sounds like an ordeal. So, I will have to use what I have.

A nice bandsaw would be great down the road, but might take a while, as I would look for a quality saw.

Thanks folks,

M
 

JohnnyChance

Founding Member
Joined
Feb 28, 2011
Messages
3,418
Reaction score
14
i cant recall ever having warping after cutting with an angle grinder. i like the thin discs, and buy them in bulk when possible. i know they are a couple bucks each, but i prefer switching to a fresh disc than trying to squeak every millimeter out of each disc. the sparks dont bother me either.
 
Top