Hardening 1095

Milt

Milt

Joined
Nov 16, 2008
Messages
260
Thanks to all those who took time to help me with the 1095 annealing questions I posted a few days ago. I was able to successfully make the tool (a blade clamp to hold the knife while grinding) and it turned out rather nicely. I did not try to anneal the HR 1095. I bought new bits and tap, and proper cutting oil. It was still a tad tough to tap, but it went well.

I now have to harden it. I plan to heat it to around 1475 degrees then water quench it. I will leave it hard rather than draw it down.

What is the proper procedure for doing this: 1. How long should I take to bring the steel up to 1475? 2. How long to heat soak- 3-5 minutes? 3. Proper water quenching technique? Duration, preheat the water, etc.


Thanks,


Milt
 
If you water quench, be prepared to make another....I'd go with a light, fast oil. In the "stuff you can find locally" pile for this is vet grade mineral oil. Check your local farm supply store, it's about $15/gallon.

-d
 
I have oil. Why are you not in favor of water quench? How about my other questions. Can you help?

Milt
 
A water quench is a tad violent and does not always cool evenly. uneven cooling is the main reason blades crack, and warp in quench. A good brine would be better, but like Dekker said, heated thin oil is a better bet. You cannot leave it hard unless you want it to break. You must give it some temper. 1095 is also a very poor choice for backyard heat treating. To get it right in the quench it needs to cool from around 1500° to under 900° in under one second, or you can end up with a lot of hard pearlite instead of good martensite, and the file test will not show the difference. Mineral oil may work. I don't know. If I were going to HT 1095, I would want Parks #50. It only costs a little more, but is about as good as it gets for oil quenching 1095.
Acually water is not too fast for 1095. Brine is faster than plain water, water just doesn't cool as evenly as brine, or proper oil.
 
I was using a water quench and though that all was well when this happened. You do need a fast quench but I think its more important to keep the blade hot (1475) from the oven to the quench tank than using water for a fast quench. To get a proper quench the diagram I have seen require that the blade go from 1475 to 400 in about a second.

I keep my quench really close to the oven, practice grabbing the blade and dunk right away and make sure to move in the quench to aid cooling. Test with a file, should skate without a mark are you should be good to go. I now use used transmission fluid heated to 125 f.


cokebottle023.jpg
 
Guy's I have to disagree, on a basic file guide type clamp, he should be fine. Milt how thick is the piece your using to make a file guide? (the clamp) say 2 x 2 x 1/4"? or more you shouldnt have any problem with a water or brine quench. Where you run into a problem with water quenches is on thin cross sections 1/16 - 3/32" and under. Then deep scratches or grinding/forging imperfections can cuase stress risers and cracks. To help keep things under controll, normalize atleast 2x and quench on the 3rd heat. Be prepared to go straight to a pre-heated tempering oven to your desired hardness level. double tempering is recommended. (2 hours in / let air cool to ambiant then back in for another 2 hours and air cool.)

Jason
 
Jason-
You seem to corroborate what I intended to do. The clamp is made of 2 pieces of 1/4" thick 1095. The dimensions are 3" long X 1" wide. I can use oil if that is better, but I think water will get it hard enough. I do not intend to temper it.

What I would like to know is- 1. Should I preheat the water or oil and to what temperature? How long do I actually keep the unit in the quench? Is time really that important for what I am hoping to accomplish?

Milt
 
Jason-
You seem to corroborate what I intended to do. The clamp is made of 2 pieces of 1/4" thick 1095. The dimensions are 3" long X 1" wide. I can use oil if that is better, but I think water will get it hard enough. I do not intend to temper it.

What I would like to know is- 1. Should I preheat the water or oil and to what temperature? How long do I actually keep the unit in the quench? Is time really that important for what I am hoping to accomplish?

Milt
 
on something of those diminsions just hold it in till it's cold. YOU MUST TEMPER!
atleast to 400ºF for 2 hours twice. otherwise your 1/4" thick steel will act like 1/4" thick glass and the first good twist or drop and it's toast. (experiance talking here...) the file will still skate it for the most part. just a lil bite.

Pre heat to 125 - 150º f/
 
A wise ABS Mastersmith once told me, "the only thing water is used for in my shop, is for drinking". :D

get yourself some Parks #50. :thumbup:
 
I made a set of file guides out of 1/4" 5160 which is more forgiving than 1095. I did not temper them. I bolted them to a blank and filed away, then set the blank with clamp still attached on the bench and as I walked away, heard a tink and when I looked one of the set had snapped in half. I would do a 400f temper.
 
thats what happened to me IB, mine was made from O1 (2x2x1/4) quenched in oil, but no temper. Used them a few times, and then lightly tossed them onto my steel bench and they snapped. Still need to make me another set... Milt you listenin?
 
A freind of mine had a couple blades Rockwell tested from 1095 quenched in canola oil and came up with:

I measured 3 places on 2 blades with 2 different quench temperatures. I started with the tip, mid blade near the edge, and the spine. With quench from 1550 I measured (RC) 64,63,63. At 1600 I measured 65,64,63.
Click to expand...
 
I am listening as I have no other option because I am a novice, and I have many other questions that need answering. My day job has required me to listen with a discernible ear. As with any such forum there are diverse opinions and levels of expertise.

Oil it will be and I will temper for 2 hours @400 degrees F. If that fails to impress, I'll make another clamp and try again.


A very sincere thanks to all who took time to share your knowledge, experiences, and photos. This is a great forum!


Milt:)
 
I forgot to say that those numbers were without any agitation or circulation. With agitation and/or circulation you could likely squeeze another point or two of hardness out of it with canola...
 
I'd throw them in brine to avoid part distortion. I don't think you need to buy oil for this application.
 
I put test blanks in with my blades just to test. Usually a 1" x 2" piece of the same steel. The fun part is take one right from the quench and throw it on the floor and see how it shatters, fun and you can see the grain. After the first and second temper (400f) I put it in a vise and pound the crap out to try and break or bend. What a difference. Will usually bend quite a bit before it breaks.
 
You must log in or register to reply here.
Back
Top