1075 crack...

funkyjedi

funkyjedi

Well-Known Member
11825113_503291769828538_3941414534360921475_n.jpgHey guys (and gals)!

Well, I made (what would have been) a gorgeous bowie/fighter for my best friend out of a piece of .25 x 2: 1075 I got from Jantz years ago. I read that 1075 can also be made to have a hamon. I decided to give it a shot. I read for days, checked the fung shui in my shop, gathered the proper equipment and went to town.

I used rutland fire mortar for my clay, put it in the ht oven and took it to 1500 for about 10 minutes. I read that a shorter blade like a small bowie would be fine water quenching. I don't have parks 50, or any other kind of quench specific oil, as I typically just use canola, so I got the tap water as hot as I could and once the blade was ready, dropped it in and agitated it in short slicing movements to (hopefully) minimize the vapor jacket.

After about 20 seconds in the water, I heard and felt two distinct cracks. Kind of like an ice cube in a fresh glass of water.
Sure enough, I ground off the scale, and there staring me straight in the face were 3 ugly little splits. The blade also warped slightly to one side.

My guess is I should have used the oil? I've put 20+ hours into this thing and my heart broke. I almost swore off making knives.

I decided, what the heck and semi-polished and etched one side of the blade to see what the hamon would have looked like.... Ill post that here. It was there alright, much to my chagrin.

If you've gotten this far, maybe you can give me some advice. I am at a loss. According to MULTIPLE threads I read, hot water should have been fine for a smaller (11" over all, 6" blade) knife.

thanks in advance.

chrisfailed bowie.jpg
 
Last edited:
I can't honestly say. I've never used water. I've heard brine is a safer bet. Personally I think they are both too risky. I use only oil. Parks 50 for hamons. I have gotten some amazing results with W2, 1095 and 1075. It's just not worth the risk for me to use water or brine. Parks 50 can be purchased from Heatbath in Texas. It's around $120 for 5 gallons if I remember correctly. Worth every penny. Here is an example with the Parks and W2uploadfromtaptalk1438308326357.jpg
 
Yeah, I was crushed.
My dad actually was here on vacation and watched me make the whole thing, and I honestly think he took it harder than me when it popped. We video taped (think the kids know what video tapes are?) the whole thing and you can hear it ping on the video...
He said I should cut it all down past the cracks, but I think the cracks might have migrated beyond what I can see.
What a drag.
Good news is I can move on to a different knife to get my mojo back.
 
taylormadeknives said:
I can't honestly say. I've never used water. I've heard brine is a safer bet. Personally I think they are both too risky. I use only oil. Parks 50 for hamons. I have gotten some amazing results with W2, 1095 and 1075. It's just not worth the risk for me to use water or brine. Parks 50 can be purchased from Heatbath in Texas. It's around $120 for 5 gallons if I remember correctly. Worth every penny. Here is an example with the Parks and W2View attachment 55820
Click to expand...
This week I will look them up. You said you use it for hamons, what other steels do you use the park?
Thanks!
 
Not all 1075 is created equal. Other than the carbon content, we knifemakers need to know the manganese levels, as this has a bearing on how fast a quench is needed to reach full hardness. Aldo's 1075 has about .3%, so is very shallow hardening, and I've been told Admiral's 1075 has almost .8%.... this is a huge difference! Without knowing the manganese content is is hard to say what type of quench it needs.
After about 20 seconds in the water, I heard and felt two distinct cracks.
Click to expand...
Once the steel hit 800 degrees, it will become martensite once it reaches 400 degrees as long as you missed the nose of the curve. There is nothing to gain and much to loose if the blade remains in the rapidly cooling quench past this point. Once the blade is no longer glowing at all, it is safe to let it air cool, and it will be much less likely to crack.
 
Thanks! I will definitely make sure that I take it out earlier next time. It was well beyond glowing when it popped. I am glad you mentioned that. I also will use the correct oil on the next attempt, as I realize now how much time and effort went into a charred hunk of steel that is now hanging over the bench instead of finding its way into a sheath.
 
Its always a big let down when you're cruising along nicely on a blade.....then something you never expected goes terribly wrong. On the up side, the mistakes we make are often our greatest learning tools. At the time its a tough pill to swallow, but I know when I make a major blunder, it sticks with me, and I rarely repeat it.

Water quenching any knife steel if very risky proposition. Personally, in my own experience, its been about a 1 in 3 succuss rate. I rarely do it anymore.

These days you have to be carefull about trusting the info you find on the internet..... there's a whole lot of folks out there who give advice based on either what they've heard somewhere, or something they've read, with little or no experince backing it up.

As an example, I tell my students..... "This is how I do it" or "This is what I would recommend". I always add that whatever you hear concerning knifemaking technique (myself included), should be taken with a grain of salt until you either prove or disprove it for yourself. I've come to understand over the years that there is no absolute "right" or "wrong" way(s) when it comes to knifemaking...... only succcussful or unsuccussful. You always have to break a few eggs to make a cake, so just tuck this situation away for future reference, and give it another try! :)
 
Keeping the blade 20 seconds in the water, as it has been pointed out, is kind of begging for the "ping" sound....i've been through it :(
But with hypoeutectoid carbon amount in solution there is also the risk of interrupting too soon and having too much autotempering effect during the martensite transformation; in fact the martensite start temperature during cooling is inversely proportional to the carbon % in solution.
If 1075 is not fully austenitized, chances are that the Ms begins too high in temperature, while on the contrary you have the start of the transformation around 400 °F and an interrupted quenching may be succesfully done.

On a last note (should have been the first), i don't know if you did so, but it is advisable preceeding the final austenitization with a normalization followed by grain refinement cycling...that is of help with avoiding warps and cracks.
 
EdCaffreyMS said:
Its always a big let down when you're cruising along nicely on a blade.....then something you never expected goes terribly wrong. On the up side, the mistakes we make are often our greatest learning tools. At the time its a tough pill to swallow, but I know when I make a major blunder, it sticks with me, and I rarely repeat it.

Water quenching any knife steel if very risky proposition. Personally, in my own experience, its been about a 1 in 3 succuss rate. I rarely do it anymore.

These days you have to be carefull about trusting the info you find on the internet..... there's a whole lot of folks out there who give advice based on either what they've heard somewhere, or something they've read, with little or no experince backing it up.

As an example, I tell my students..... "This is how I do it" or "This is what I would recommend". I always add that whatever you hear concerning knifemaking technique (myself included), should be taken with a grain of salt until you either prove or disprove it for yourself. I've come to understand over the years that there is no absolute "right" or "wrong" way(s) when it comes to knifemaking...... only succcussful or unsuccussful. You always have to break a few eggs to make a cake, so just tuck this situation away for future reference, and give it another try! :)
Click to expand...

Mr. Caffry, it means a lot that you and ALL the people on here took time to respond. Thank you so much.

As a parent/teacher/coach, I have said many of the same thing to my kids/students/players about the gifts of mistakes. In fact, in my classroom I often do not let students erase their work when they make a mistake, so they can reference it and not repeat it. That is the reason that knife is dangling from a pegboard hook above my workstation.

This forum is full of awesome people and I probably sound like a broken record, but thanks again for your time and input. The next one will be awesome... and speaking of..

I ordered some more 1075 last night. As soon as it gets here, Ill give it a go. One question though, if it sold as annealed, should I still normalize it as Stezann mentioned? With my oven, it shouldn't be a problem, just checking.

Thanks again all!
 
It depends, both on the mill job and on your grinding attitude.
If it is coarsely spheroidized from the mill, normalizing will help redistributing the carbon quicker, allowing a shorter final soak, after the grain refining cycles.
if it came finely spheroidized, and you provide to grind it avoiding overheating, you should be ready, and could skip the normalizing+refining cycles.
Be aware that grinding hard will likely introducing uneven stresses, leading to warps, as it does uneven heating up during HT.
But for these latter issues just a distension treatment at 1270-1300 °F will help.
 
Well, thats the plan for the next one. I just hung up the phone and a pail of Parks is on the way. Between a better quenchant and proper steps for heat treat, I have a much better feeling about the next one.

I wanted to share this as well, I made this little straight razor out of a scrap from the 1075 I cut off of the first blank. I quenched in canola, and it came out pretty well. you can see a slight hamon appearing. Being my first one, I got antsy and probably could have sanded down farther, but I went to 1200 and then hand polished with flitz.straight.jpg
 
it is a nice hamon.
Someday if you will you could still keep polishing it. Nice job, and good to you for getting the P#50
 
You must log in or register to reply here.
Back
Top