that's an interesting idea. If the carbon content is there - maybe a good brine quench would sort it out...Originally Posted by Jim Koepke
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Member
that's an interesting idea. If the carbon content is there - maybe a good brine quench would sort it out...
Contributor
Why bother. They are basically junk when you buy them. I think better to spend time doing something useful.
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Member
So.. Not being the sort to leave well enough alone - I gave rehardening one a crack.... It didn't want to behave nicely like a good high carbon steel does... It needed to get a lot hotter than I am used to and then it took quenching really really hard (a small bucket full of crushed ice wet down by brine + dish soap + jet dry) to get it to harden up to where a file would mostly skate... The W1 I have fooled with in the past didn't need any of that.... I had no trouble getting it screaming hard without any of these gyrations....
Yeah, so probably the best course of action is to just say this trial has come to an end...
Aldi chisels are what they are.
You can get a lot of work out of them.
But what they are is what you can get out of them....
It's not a bad thing - it's just what it is.. And if it works for you - awesome.
Contributor
My wife shops at Aldi and has been looking for the fabled chisels for years. None to be had. If anyone has a set they can part with, I’d love to do some hardness testing to see what I can learn about them. Part of the testing would be destructive. Based on comments in this thread, I’d mill a slot into the back and test the interior hardness as well as on the surface.
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I would really be interested in a test of retained austenite.... Based on their behavior - there may be no shortage......
Contributor
Pete,
They are only available around Father's Day from what I've seen.
Fred
"All that is necessary for the triumph of evil is that good men do nothing."
“If you want to know what a man's like, take a good look at how he treats his inferiors, not his equals.”
Member
I have a set I've never opened. If I can get them to fit in a flat rate box, I'll be glad to donate them to be tested.
FWIW, I have another set, and use them pretty regularly. I'm a newby to traditional wood working, but I get good service from them. I am not a good judge of edge retention, ie; judging by how long they keep an edge, as I really don't have a lot to compare to. An old Marples, old 750 and a couple of Fulton vintage, but mine all stay at 25 degrees except the Marples, which is at 30. I cannot tell any difference in the actual working time between them, but they all sharpen up really fast with a good stropping.
Shoot me a PM and I'll get them in the mail to you.
Incidentally, no they are not very pretty chisels. But they are long compared to my others, and they are thinner and lighter, which I tend to like most times.
Contributor
Aldi's ads come out on wednesdays.....check out the ads the week before fathers Day.....in fact, start two weeks before. Be there when the sale starts,,otherwise the 12 packages will be gone.
Contributor
It would be interesting to know the chemical composition of the Aldi chisels.
Personally, I would never heat treat something well above the desired temperature and then severely quench. You are asking for bitterness issues and potential fracture issues. The high Temperatures can cause blown grain and poor properties. Using the chisel with no tempering is risking problems. However, without the chemical composition all of the conjecture is just that.
As to retained austenite, I really doubt that it is a problem. Typically, more of an issue in high carbon and higher alloy steels.
Contributor
Today I made the dumb mistake of using an Aldi chisel bevelled at 20* to square up (chop) the shoulder of a tenon. Shouldn't have used a mallet with a bevel angle that low, no matter how lightly I tapped - even 6-8 taps chipped the edge badly. Some of it might have been the steel, but I havent seen chipping before, when I used them only for paring. I gotta believe the bevel angle was the main culprit.
Fred
"All that is necessary for the triumph of evil is that good men do nothing."
“If you want to know what a man's like, take a good look at how he treats his inferiors, not his equals.”
Contributor
Next time, just rest your chin on the end of the chisel, and use that to "pare" the tenon with.....that is how I do mine.
Member
I don't have a set of the Aldi chisels, but if we have an old time machinist here that does, he/she may be able to provide some guidance by taking one to a grinding wheel and "reading" the sparks, for a basic understanding of the steel's composition.
If the thunder don't get you, the lightning will.
Contributor
Spark testing may give you a basic understanding of carbon but not much else. The other elements make a big difference such as Mn, Cr and others you will not know.
I worked in a steel mill and we had professional spark testers and am very familiar with what they can and cannot do. Most spark testers were replaced with portable spectrometers that give pretty good results. If I was still working, it would be so easy to get a full analysis but retirement is great.
Contributor
Good tip. Thank you Steve.
"All that is necessary for the triumph of evil is that good men do nothing."
“If you want to know what a man's like, take a good look at how he treats his inferiors, not his equals.”
[OP]
Member
Arc spark machines do quite a good job when they are properly maintained.... Not an inexpensive proposition...
I did grind on it a bit to look at the sparks... It doesn't spark like an old chisel or a decent file..... It definately has "less" carbon - but how much? No idea...
Larry, I didn't start off with a high temperature and very aggressive hard quench - that's where I ended up.... I tried non-magntic + oil quench - nothing useful.. Then non-magnetic and a gentle brine... Better but very shallow. Non-magnetic + harder quench - better... Then finally quite a bit hotter + very hard quench... Seemed to mostly thru-harden ... Based on the results with different files I own - I would estimate Rc64 range..
By that point - it was badly warped and had a small crack in it.... I broke it to look inside... Very fine grained crystal structure even with all my ham-fisted abuse.... Very much unlike a Harbor Freight chisel - which had grains that looked like beach sand... So that's a huge positive... The grain structure was beautiful on the Aldi chisel...
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