Parks 50

Randy Lucius

Well-Known Member
I'm using 1084 and 1075. Heating in a mini-forge to non-magnetic and quenching in Canola oil. Would there be any advantage in switching to Parks 50?
 
Thanks Jason! So there wouldn't be an increase in edge hardness or edge retention moving to the Parks 50? That has more to do with the properties of the steel itself rather than the quench. Correct?
 
Thanks Jason! So there wouldn't be an increase in edge hardness or edge retention moving to the Parks 50? That has more to do with the properties of the steel itself rather than the quench. Correct?

Possibly! Just because you can do a quench with Canola, does not mean your are getting the full potential of the steel!

The man that can best answer that would Kevin Cashen!! Here is a couple of links to his info. If you can't figure it out in there, contact him on the forum!!
http://www.cashenblades.com/heattreatment.html
https://knifesteelnerds.com/2018/06/25/review-kevin-cashens-guide-to-1084/

He has never balked at any stupid question I threw at him but he has enlightened me many times!!
 
I'm not a expert so not sure about the retention or hardness but I know to get a good Hamon you want something fast like water for the best hamon activity. But with water your going to break like every other Blade. P50 is engineered to be fast like water but not break blades like water if you get what I mean
 
The problem here is that you have 2 different types of steel. 1084 is deep hardening, which is fine with canola or would be even better with parks AAA, 1075 is shallow hardening which would benefit from using parks 50.
 
The problem here is that you have 2 different types of steel. 1084 is deep hardening, which is fine with canola or would be even better with parks AAA, 1075 is shallow hardening which would benefit from using parks 50.
Thanks Jeremy. Can I use Parks 50 for 1084 and 1075? Or should I use Parks AAA on 1084 and Parks 50 on 1075?
 
Hmmm, I hope I don't step on too many toes here, but I would like to give a little input on a few bits of info here. What I am putting forth will only be what is recommended by the manufacturers, industry and what I have confirmed with years of experience and testing in my own shop. I have seen the 1084 labeled deep hardening before, and this is a misconception that needs to be cleared up (sorry Jeremy, no disrespect intended). The concepts and terms of "deep" or "shallow" hardening is based upon the Jominy end quench method of describing the hardenability of a given steel. 1084 is a 10XX Series steel and, along with all other 10XX steels is very much a shallow hardener. Any oil not in the 7 to 10 second range, like Parks AAA (11-14 second) will leave plenty of pearlite colonies in any piece of 1084 that is much over .187" in cross section, or even less. I have seen 1084 referred to as deep hardening several times before, and I am not sure where this idea originated considering the chemistry and behavior of the steel. Park Metallurgical/Heatbath #50 is matched with any steel with a 10 as the first two numbers (simple carbon steels) and the W (or water hardening) series.

Parks #50 was developed as a much better alternative to the treacherous nature of water for steels that were initially designated as "water hardening", or ones that would be shallow hardened in the Jominy test which actually used a water jet/spray as its coolant. Alloy steels that easily hardened to full depth were deemed deeper hardening and were designated "oil hardening".

Which brings me to the next point, (sorry John, but you know we are cool, and I know you get it) that #50 is definitely designed to replace water, and not oil, in hardening steel. Using Park#50 on deep hardening steel is a serious mismatch despite how lucky many folks have gotten. I too have used Parks #50 on deeper hardening alloys and managed to survive the ordeal. But this is like the folks who say they have smoked their entire lives with no ill effects- all this means is that they have been lucky, it does not change the fact that smoking is an incredibly hazardous habit that has killed thousands.

I am only pointing this out because I have seen a trend in our business to use Parks #50 as a panacea to avoid buying another quenchant when working with a steel that is ill suited for water type quenching, this is not the best approach and there is a reason that different speed quenchants were developed for different steels. Using the same quenchant for a vast array of alloys, from very shallow to very deep hardening, is like keeping your drill press on the same speed regardless of what size bit you are using, or what material you are drilling. You can do it, but expect to buy a whole lot of drill bits in your career. I would say that if any makers are set on using Parks #50 on any steel from 1095 to O-1 that it would be cheaper just to get a gallon of canola and call it good. After all, one doesn't need the expense of a Bridgeport mill if they will never change the speed of cut.

Luciusx5, in my experience, Parks #50 is ideal for both of your steels, i.e. 1075 and 1084, I spent a good six months last year looking at 1084 under a microscope and #50 yielded optimum results. If you want to work with hamons, 1075 in Parks #50 will allow you to be a Rembrandt in selective hardening. With either of these steels, if you find the hamon working under the clay, keep that oil and just adjust your pre-hardening thermal treatments and hardening temp to affect the responsiveness to the clay.
 
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Oh heck, since I have inserted myself in the discussion now (sorry, I don't mean to hog the bandwidth), about that canola...

Canola is a fairly fast quenching oil, but these are the advantages of springing for the engineered quenchant-

Canola can come close to the #50 in the upper range of the curve, i.e. the area around 1,000°F where it needs to cool as fast as possible to avoid making pearlite in the blade, but in the lower range it is just as fast, and this is not desirable. From about 600°F to ambient the ideal quenchant will slow down and allow the incredibly stressful process of martensite formation to occur with as little added stress as possible. This is one of the critical features that are added to proper quenching oils. Their cooling curves look like a backwards "S" so that while the blade is actually hardening it is done in a gentler fashion that reduces chances of warpage or cracking.

But the bigger advantage that you are investing in with a proper quench oil is consistent results due to overall chemical stability. Canola is an organic oil and will start changing as soon as you open the bottle. Over time it will literally go rancid, it is after all "vegetable" oil. But when you start plunging 1475°F steel into it is going to chemically change on every quench. Your 5th blade will not get the exact same treatment as your first. A whole lot of science and engineering has gone into a proper quench oil to insure that it will produce the exact same results in the thousands of parts that will be quenched in it. I have been using the same 5 galllons of #50 for many years now with the same consistent results (the same with my AAA and Houghton products).

That is not to say that there are not times when it could just be a waste of money to upgrade from canola. If one is planning on edge quenching, (I wish they wouldn't but if they are), then the canola is the better route as the overheating and flashing will just ruin the Parks #50 in a couple of quenches anyhow. If you have no means of housing the oil in a container that will allow you to maintain it, it may be better just to rotate out the inexpensive canola. Moisture, dust, dirt and other gunk will ruin the investment in a good oil, so you really want to keep it in a large metal container that can be sealed up when not in use. And if a person only wants to make a couple of knives and is not looking to pursue it on a larger scale or profession, the canola will make your two or three family heirlooms well enough.
 
Kevin thanks for those couple of posts.....fantastic info.

Your examples of getting lucky using a less than optimal oil really drove it home for me. I never really liked quenching 80crv2 in parks 50 from our previous conversations bit did it exactly for the reason you highlighted......it was the only steel I used occasionally that wasn't ideally suited to parks 50 but thought I'd use what I had rather than buy a new oil.

Due to seeking a new steel supplier, I'm certain some 01 is in my future and I will be definitely ordering some medium speed oil to accompany it. Thanks for weighing in on these threads.
 
@Kevin R. Cashen Thanks for correcting me and giving everyone the information they need! You'd think after sitting in TWO of your heat treating seminars at Hammer ins I would have learned something haha!
 
1084 referred to as deep hardening several times before, and I am not sure where this idea originated
I believe people think that it is a deep hardening steel because you can not get a good Hamon with 1084. In fact I have read on a few different forums
"1084 does not get a good Hamon because the amount of Mn in it makes it deep hardening and that is why its a bad choice for a hamon".
 
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