AAA and Parks 50 data sheets

BossDog & Owner
Staff member
USAknifemaker is adding a couple quench oils to our listings.

Parks 50 and AAA quench oils.

attached are info sheets about both as a place to put them until I can find somewhere better.

From the Heatbath site:
#50 QUENCH OIL Low viscosity quench oil that approaches water in quench speed, yet gives a more uniform, less severe quench than water. Recommended for open quench system operating below 120°F.

AAA QUENCH OIL The most popular, widely used quench oil. This patented accelerated quench oil provides a maximum, uniform cooling rate for austenitized steels, as well as clean, easily washed work when properly maintained.

It would be nice to get some feedback on which oils work "best" for which steels.


  • 50 Quench Oil.pdf
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  • 50 QUENCHOIL_EN.pdf
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  • AAAQuenchOilRev2(TD).pdf
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BossDog & Owner
Staff member
Which oil should I use for which steel?

Generally, some steels require a fast "water - like" (Parks 50) quench. Steels like W1, W2, 1095 come to mind
Some steels don't handle a "fast" quench and will do better with something slower (Parks AAA). Steels like 1080/1084, 5160

Generally, Parks 50 is considered a "fast" quench, what ever that is, with a Nickel Ball Time (standard test) of 7-9 seconds
Generally, Parks AAA is a "medium fast" quench, what ever medium fast is, with a Nickel Ball Time of 9-11 seconds.

The industry settled on a test using a Nickel Ball heated to a certain temp and then quenched. Measurements on the temp reduction were taken to determine quench speed of the oil being tested.

Can you use one quench oil for everything? Sure but it will impact the results you get and probably not in a good way. If you use an oil that is "too fast", you might get excess warping or cracking. If you use an oil that is "too slow", you may not achieve the hardness the steel is capable of.


Is the viscosity of the oil the determining factor that makes the oil "fast" or "medium fast?" If Parks 50 is high viscosity and is a fast quech, is AAA a slower quenchant because it has a lower viscosity?



"The Montana Bladesmith"
I think something worth mentioning, that not many realize/understand. There are few, if any heat treating standards out there for steels in the dimensions found in knife blades. For years I have seen many refer to various heat treating manuals as the "go to" source for "how to" heat treat blades. Early in my career, I tried to use common heat treat manuals as definitive sources for how to heat treat blades....and constantly had problems. That is until I noticed that ALL the heat treat manuals contain either a "foot note" somewhere in the first couple of pages, or a "post script" somewhere in the last couple of pages that states..... "All information contained in this manual are based on a 1" cross section of the specified material". What that means is a 1" x 1" x 1" cube of a given steel type. This got me to thinking..... does the size/shape make a difference? After years of experimenting, the answer is a resounding YES. Based on all of that experimenting, and subsequent testing I've had done, the general rule for heat treating blades steels that are commonly used when forging (the quenching portion) is that in order to achieve full hardness, the steel must cool from it's austinizing temp, to 400F or less, in 6 seconds or less.

The take away here is it use the information presented in heat treat manuals as a STARTING POINT. Not as an absolute.

Another detail that I've found many miss is..... whatever operation is being performed, the steel must be at a given temp WHEN the action takes place....... the best example I can offer is quenching. I have fielded many questions from folks who have troubles getting steel to harden. In many cases I have discovered that once a person gets a blade to temp, then remove it from the heat source, and "walk" to the quench tank.....meaning that the steel has cooled well below the austinizing temp before it hits the quenchant. If your quench tank is more than a "turn" away from your heat source, either move it closer to the heat source, or move the heat source closer to it. Sound simple, but you'd be surprised at how many never think about heating a blade to temp, then walk "across the shop" to quench it.

As a side note, for years I used only Vet Grade Mineral oil as a qenchant. While it may not have been "the best", it got me through both my ABS Journeyman Smith, and Mastersmith testing. Not long after achieving my Mastersmith rating, I started trying various commercial quench oils. Each had/has it's own unique characteristics..... some good, some not so much. In the end I decided to stick with Parks 50, and learned the "work arounds" for using it on steels that might do better in a different quenchant. Sure, I've wrecked a LOT of blades, but I've also gained a lot of valuable insight in the process. Whatever an individual chooses to use, understand that it's going to require that you put in some work, and wreck some blades before you get all figured out.....even then there's always more to learn. That's what I love about what we do.....every single day that I walk into the shop.... I learn something new! :)
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There are few, if any heat treating standards out there for steels in the dimensions found in knife blades.

This is exactly where I'm at - building the shape I want to experiment with heat treating. I've found you and others write not to go to thin. So that's what I'm doing right now, grinding out a set of blades of known steel (80crV2) for HT'ing while leaving them thick enough not to give me any other trouble in order to rule out variables. I want to just see if I can get it right.

Good to hear about your success with vet oil. My quenching options are vegetable oil, two stroke oil, motor oil, or rendered animal fat with viscosity similar to vegetable oil.

Another detail that I've found many miss is..... whatever operation is being performed, the steel must be at a given temp WHEN the action takes place....... the best example I can offer is quenching.

Being brand new to the HT'ing arena I can see this being an issue for blade failure even if I do get the Quench and Tempering temperature variations right. It will be difficult for me to tell how much the blade cools before going into quench.

Does a full quench help beat the time as opposed to edge quench? .

I wonder if 8 blades is even enough? I have six more thick bars I wonder if I should turn them into 12 knives instead of only trying with six? That would give me 14 total blades of 80crV2. I'll be breaking and abusing them. But from what you've said it sounds like I'm at a good starting point.

I'll research more and post questions more on what I'm looking for with each blade when I'm finished. Right now I'm shaping and grinding.

Hey thanks again for the detailed answer, Ed!