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I am needing some help on Multiple Quench...I am trying to learn this technique, but I don't know the step by step process. Can someone please give me advice or the know how on this process?

Linda, how many blades do you intend on quenching at once? There are probably fixtures that can be made to hold several blades at one time, I have consulted for operations that used automated heat treating facilities that could quench dozens or even hundreds of blades in one fell swoop but that is beyond the scope of most bladesmith shops. You would want a kiln with around a 12" internal space to accommodate several blades without a heavy gradient from the elements to the center and it would probably be best to make your holder from a material that could handle repeated heating cycles. I would also suggest a wider horizontally oriented quench tank over a vertical configuration to handle the blades side by side. Industrial applications use impellers or circulating pumps to handle large part volumes by moving the oil around the parts while most bladesmiths can simply move the singular blade in the oil. And circulation would be very important since the side by side blades would heat the oil much more than one, especially the blades in the middle of line up. I have thought about the possibilities before but with the volume I work with I decided that quenching each blade individually would work better with my salts, this gives me the time to work with each blade from beginning to end.

Hello Linda and welcome. Are you asking about quenching one blade multiple times? Such as Ed Fowler does with 52100. I will let others add to this one as I am not well versed on that subject. I know that Ed Fowler does have a dvd of his process, perhaps Kevin will add his thoughts on multiple quenching and it's effects.

Brion

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Hello Linda and welcome. Are you asking about quenching one blade multiple times? Such as Ed Fowler does with 52100. I will let others add to this one as I am not well versed on that subject. I know that Ed Fowler does have a dvd of his process, perhaps Kevin will add his thoughts on multiple quenching and it's effects.

Brion

Oh, now I see. I most often hear those methods referred to as “triple quenching”. Linda, what steels do you prefer to work with, and what tools do you have to heat it? Depending on your choice you may or may not need to go to many extra lengths to accomplish your goals.

Bladesmiths are an industrious lot and will work out many clever ways to over come adversity and problems. The forge and anvil are the tools of the bladesmith that date back almost to prehistory and for over 2,000 years they were perfectly matched for the simple iron-carbon steel that was available. Then in the first parts of the 19th century intentional alloying was introduced to literally change everything and while all new more sophisticated tools and methods were developed to handle these new and more complex steels the simple coal forge sort of got left behind by industry and its new steels.

For the most part bladesmiths do quite well with modern steels since there are many still around that are simple enough to respond to our methods and still produce excellent results. 1070, 1075, 1080, 1084, 1095, W1, W2 are all examples of modern steels that are still one or two alloying additions away from the simple steels of the past and these will respond very well to heat treatment with forges without much extra maneuvering to accommodate more complex issues. However many bladesmiths like to experiment with other steels that offer a new set of challenges to simpler heating equipment, steels that have added elements or higher carbon levels which will throw some nasty curveballs at you if you treat them like 1084. Some require much tighter temperature controls and will not tolerate overheating at all, and probably need a longer time at a precise temperature to avoid little annoying problems. In this case the forge, magnet and eyeball can be treacherous enough to make erring in the side of caution the best route, this is often in the form of keeping the temperature low and getting out of the fire as soon as possible.

This leaves a steel requiring a precise time and temperature soak with a lack of carbon in solution to maximize its properties and here is where some clever smiths developed some methods to get this unsatisfactory condition up to acceptable levels. Instead of risking an over heated condition, they instead stay in the safe temperature ranges and put a percentage of the carbon into solution and then quench to trap it there. Then on the next heat this carbon will not need to be put into solution since it is already there and they can take another bite out of the undissolved carbon stash and do the same again. By the time they get to the third go around they may very well have as much carbon into solution as the steel needs without having to use more sophisticated equipment. It is actually pretty clever when you think about it.

Smiths using this method will often say they saw noticeable improvements in blades previously done using the same simple equipment on a particularly finicky steel. Often folks who favor lower temperatures and simpler equipment (such as torches or simple forge setups) using steels with high alloying contents (such as chrome) and high carbon contents (over .8%) will have some extra hurdles to overcome and this method is a rather ingenious way around having to invest a fortune in the precise equipment the steel would normally require.

However if your interests are in trouble free steel and heat treating, careful selection can give you wonderful results without added steps to overcome unintentionally self imposed hurdles. As I type this I am waiting to fly home from the Intro class I just taught here in Maine, and my students, (some had never heated steel before), produced some fantastic blades with just a forge and good oil, due to a steel well matched to the methods available. We used 1084 and I am confident that I couldn’t have produced much better results than if I had used my salt baths back home. So if you have good proven simple steels well matched to your methods you may be just fine with your current approach.

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Oh, now I see. I most often hear those methods referred to as “triple quenching”. Linda, what steels do you prefer to work with, and what tools do you have to heat it? Depending on your choice you may or may not need to go to many extra lengths to accomplish your goals.

Bladesmiths are an industrious lot and will work out many clever ways to over come adversity and problems. The forge and anvil are the tools of the bladesmith that date back almost to prehistory and for over 2,000 years they were perfectly matched for the simple iron-carbon steel that was available. Then in the first parts of the 19th century intentional alloying was introduced to literally change everything and while all new more sophisticated tools and methods were developed to handle these new and more complex steels the simple coal forge sort of got left behind by industry and its new steels.

For the most part bladesmiths do quite well with modern steels since there are many still around that are simple enough to respond to our methods and still produce excellent results. 1070, 1075, 1080, 1084, 1095, W1, W2 are all examples of modern steels that are still one or two alloying additions away from the simple steels of the past and these will respond very well to heat treatment with forges without much extra maneuvering to accommodate more complex issues. However many bladesmiths like to experiment with other steels that offer a new set of challenges to simpler heating equipment, steels that have added elements or higher carbon levels which will throw some nasty curveballs at you if you treat them like 1084. Some require much tighter temperature controls and will not tolerate overheating at all, and probably need a longer time at a precise temperature to avoid little annoying problems. In this case the forge, magnet and eyeball can be treacherous enough to make erring in the side of caution the best route, this is often in the form of keeping the temperature low and getting out of the fire as soon as possible.

This leaves a steel requiring a precise time and temperature soak with a lack of carbon in solution to maximize its properties and here is where some clever smiths developed some methods to get this unsatisfactory condition up to acceptable levels. Instead of risking an over heated condition, they instead stay in the safe temperature ranges and put a percentage of the carbon into solution and then quench to trap it there. Then on the next heat this carbon will not need to be put into solution since it is already there and they can take another bite out of the undissolved carbon stash and do the same again. By the time they get to the third go around they may very well have as much carbon into solution as the steel needs without having to use more sophisticated equipment. It is actually pretty clever when you think about it.

Smiths using this method will often say they saw noticeable improvements in blades previously done using the same simple equipment on a particularly finicky steel. Often folks who favor lower temperatures and simpler equipment (such as torches or simple forge setups) using steels with high alloying contents (such as chrome) and high carbon contents (over .8%) will have some extra hurdles to overcome and this method is a rather ingenious way around having to invest a fortune in the precise equipment the steel would normally require.

However if your interests are in trouble free steel and heat treating, careful selection can give you wonderful results without added steps to overcome unintentionally self imposed hurdles. As I type this I am waiting to fly home from the Intro class I just taught here in Maine, and my students, (some had never heated steel before), produced some fantastic blades with just a forge and good oil, due to a steel well matched to the methods available. We used 1084 and I am confident that I couldn’t have produced much better results than if I had used my salt baths back home. So if you have good proven simple steels well matched to your methods you may be just fine with your current approach.

|quoted:

Oh, now I see. I most often hear those methods referred to as “triple quenching”. Linda, what steels do you prefer to work with, and what tools do you have to heat it? Depending on your choice you may or may not need to go to many extra lengths to accomplish your goals.

Bladesmiths are an industrious lot and will work out many clever ways to over come adversity and problems. The forge and anvil are the tools of the bladesmith that date back almost to prehistory and for over 2,000 years they were perfectly matched for the simple iron-carbon steel that was available. Then in the first parts of the 19th century intentional alloying was introduced to literally change everything and while all new more sophisticated tools and methods were developed to handle these new and more complex steels the simple coal forge sort of got left behind by industry and its new steels.

For the most part bladesmiths do quite well with modern steels since there are many still around that are simple enough to respond to our methods and still produce excellent results. 1070, 1075, 1080, 1084, 1095, W1, W2 are all examples of modern steels that are still one or two alloying additions away from the simple steels of the past and these will respond very well to heat treatment with forges without much extra maneuvering to accommodate more complex issues. However many bladesmiths like to experiment with other steels that offer a new set of challenges to simpler heating equipment, steels that have added elements or higher carbon levels which will throw some nasty curveballs at you if you treat them like 1084. Some require much tighter temperature controls and will not tolerate overheating at all, and probably need a longer time at a precise temperature to avoid little annoying problems. In this case the forge, magnet and eyeball can be treacherous enough to make erring in the side of caution the best route, this is often in the form of keeping the temperature low and getting out of the fire as soon as possible.

This leaves a steel requiring a precise time and temperature soak with a lack of carbon in solution to maximize its properties and here is where some clever smiths developed some methods to get this unsatisfactory condition up to acceptable levels. Instead of risking an over heated condition, they instead stay in the safe temperature ranges and put a percentage of the carbon into solution and then quench to trap it there. Then on the next heat this carbon will not need to be put into solution since it is already there and they can take another bite out of the undissolved carbon stash and do the same again. By the time they get to the third go around they may very well have as much carbon into solution as the steel needs without having to use more sophisticated equipment. It is actually pretty clever when you think about it.

Smiths using this method will often say they saw noticeable improvements in blades previously done using the same simple equipment on a particularly finicky steel. Often folks who favor lower temperatures and simpler equipment (such as torches or simple forge setups) using steels with high alloying contents (such as chrome) and high carbon contents (over .8%) will have some extra hurdles to overcome and this method is a rather ingenious way around having to invest a fortune in the precise equipment the steel would normally require.

However if your interests are in trouble free steel and heat treating, careful selection can give you wonderful results without added steps to overcome unintentionally self imposed hurdles. As I type this I am waiting to fly home from the Intro class I just taught here in Maine, and my students, (some had never heated steel before), produced some fantastic blades with just a forge and good oil, due to a steel well matched to the methods available. We used 1084 and I am confident that I couldn’t have produced much better results than if I had used my salt baths back home. So if you have good proven simple steels well matched to your methods you may be just fine with your current approach.

Thank You for all this information. I am using 5160 so I was wondering if this steel was good enough for the process. The steps are the inbetween steps of quenching. When I first bring my blade to critical temp and quench it the first time how long should I wait before I quench it the second and third time and what are the steps after you quench it the first time? Should I allow the blade to cool completely or what?

I will tell you how I heat treat 5160. It will give you a starting point for your own experiments. I am assuming you have good temp control.

When you are finished forging the blade, make sure it is scale free. Heat to about 1575, no soak time, just make sure the color is even. Quench the whole blade, using agitation, for about 10-15 seconds. Check for warps, and straighten if needed, while still too hot to handle without heavy gloves. Reheat a second time, but only heat to 1550, soak for about 3 min, quench again, and check for warps. Reheat to between 1525 and 1550, soak for a few minutes, then let air cool in still air.

These steps replace the typical thermal cycles, and will leave the blade soft enough to drill and tap.

Grind the blade to 220grit. Heat to 1525 for a three minute soak, and quench.

Definitely better performance than single quench with 5160.

I passed my Journeymans performance test using this treatment. The final heat treat quench was an edge quench. I drew it to 375 degrees twice for 2 hrs each time. Bent to 90 without any cracks at the edge.

I started experimenting with this on 5160, after MS Howard Clark shared a similar type regiman for the L-6 I was working with at the time. Hope this helps. Dan

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I will tell you how I heat treat 5160. It will give you a starting point for your own experiments. I am assuming you have good temp control.

When you are finished forging the blade, make sure it is scale free. Heat to about 1575, no soak time, just make sure the color is even. Quench the whole blade, using agitation, for about 10-15 seconds. Check for warps, and straighten if needed, while still too hot to handle without heavy gloves. Reheat a second time, but only heat to 1550, soak for about 3 min, quench again, and check for warps. Reheat to between 1525 and 1550, soak for a few minutes, then let air cool in still air.

These steps replace the typical thermal cycles, and will leave the blade soft enough to drill and tap.

Grind the blade to 220grit. Heat to 1525 for a three minute soak, and quench.

Definitely better performance than single quench with 5160.

I passed my Journeymans performance test using this treatment. The final heat treat quench was an edge quench. I drew it to 375 degrees twice for 2 hrs each time. Bent to 90 without any cracks at the edge.

I started experimenting with this on 5160, after MS Howard Clark shared a similar type regiman for the L-6 I was working with at the time. Hope this helps. Dan

Thank You so much.I will try your method this morning. 5160 is the only steel I use, I am just experimenting with different methods. I was told that the multi quenching was the best route to take when I am making my knives for my journeymans...so i will let you know how things turn out. Once again thank you

T

What Dan has outlined is an excellent approach if one wishes to use multiple heat cycles to affect the steel, and the nice thing about it is that it does not interfere with or complicate the hardening operation, since it is actually part of the normalizing process directly following forging. I use very similar methods on my own forgings and then move on with much more hassle free and uninterrupted hardening operations. Using a magnet to check when it is ready to reheat is a handy tip, the magnet will stick again as soon as you are ready to reheat the steel in normalizing.

Repeating the actual hardening operations can give the results I outlined in my previous post, but along with the gains toward a standard outcome one also gets all the things multiplied that make you nervous while hardening; your distortion issues will not just repeat, they will get more intense with every quench not followed by some sort of stress relieving operation. You can clearly see how the cycling in the normalizing process as outlined by Dan will deal with all of that.

On a side note, 5160 is what is known as a hypoeutectoid steel, this means that it has less than .8% carbon so it has the exact opposite characteristics that I outlined about much higher carbon steels, it needs more heat to push that lesser carbon amount through all of the extra iron present this is why you see temps like 1525F in Dan's process, he is aware of this and is addressing the issue accordingly. Do remember however that one must always be careful not to overheat. 5160 is particularly friendly to watching the decalescence for your temperatures if you do not have a pyrometer. Just watch for that tell tale shadow in the steel when it turns red and as soon as that shadow is replaced with a nice even glow you are good to go with 5160.

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I am needing some help on Multiple Quench...I am trying to learn this technique, but I don't know the step by step process. Can someone please give me advice or the know how on this process?

Hi Linda,

Ed Caffery has written an excellent artical on using 5160 for the ABS jouneyman's test, and goes through the heat treat process step by step. Here is the link:

http://www.caffreyknives.net/journeymanarticle.html

Good Luck,

Bob