Is Parks 50 too fast for 1080/1085 steel

C Craft

Well-Known Member
I have some new quench oil on the way and mentioned to someone on another forum about using Parks50 on 1080/1804 and they made the comment it was too fast for those particular steels. Anyone want to share some knowledge on that subject? :les:


"The Montana Bladesmith"
Parks 50 is what I'm using......1080, 5160, 52100, etc. I did find that it is too fast for 52100 if pre-heated.....I use it on everything at room temp.

Kevin R. Cashen

Super Moderator
This bit of misinformation from elsewhere is problematic enough to cause me to take a moment to leave the sidelines as referee and to add some words. No oil is too fast for shallow hardening steels such as 10XX or W series, which were suited for water quenches in thicker sections but can be hardened quite well in oil in thinner sections. I have been doing this whole knifemaking thing for over 30 years now and have yet to crack a blade in oil. Not that it can't be done if you blow the heating badly enough. I have tried to intentionally cause problems for metallography samples and the only way I could get even a fast oil to stress the steel to that level is to overheat it, also leaving it in an as-quenched condition without tempering. Every such argument I have seen thus far about #50 is pure sour grapes and intellectual dishonesty from people bent on never using it, and wanting to feel less alone by talking others out of trying it.

For what it is worth, not only do I do my own testing and analysis of the effects of heat treatment, I have also consulted for companies developing their own heat treating methods and materials. My tests consist of standardized samples replicating blade cross sections hardened using salt baths and the subject oil in a heated bath monitored for exact temperature. The samples are then cross sectioned on a water cooled sectioning saw and mounted for metallographic examination and millimeter by millimeter hardness testing on the Rockwell "C" scale, I can also have them microhardness tested when need be. I have found excellent fast oils like Parks #50 capable of thoroughly hardening (65 HRC+) 1095 in sections approaching 5/16" in the right heat ranges (85F-108F), with no cracking. But along with the Rc numbers is the amount of residual pearlite left in the sample as revealed by metallography, and a good oil can reduce it to inconsequential amounts in thicker sections and completely eliminate it in sections under 1/4".

The vast majority of problems in the hardening operation are the result of improper soak heat or quenching practices. The oil just does what it does, but it needs a piece of steel prepared to fully harden, and then the maker needs to do his part in proper agitation and maintenance. Peoples assessment of the results are completely subjective and that is why so many quenchants work so well for so many people. I decided not to listen to people but to look to the steel itself for the answers, what the actual hardness level is and what structures are inside the steel are not subjective, they just are, and there is no spinning it as they have no agenda.

I do always point out that Parks #50 is all the craze these days (perhaps partly my doing from years ago), and one can get the impression that it is the only quench oil to use- that is nonsense, there are many excellent quench oils out there that can do the job and are much easier to get. I cannot recommend Houghton International enough for having the largest line of quality quenchants that they are willing to sell to even little guys like us.

Now as a moderator I mentioned recently in another thread- we have free will and the right to heat treat any way we like, if we like water we can use it, if we like 10w30 we can use it, if we like our favorite brand of quench oil, by all means use it! But allow others the same freedom and leave the personal agendas out of it, when giving helpful facts we should keep it confined to the facts. I have seen a great disservice to factual information done in other venues due to personal axes to grind, we can help remedy that misinformation here if we we help each other with facts, and that is why I felt the need give some of my own input here.


I have been using Parks 50 on 1084, 1095, 15N20, and 5160 with great results. Any time I have observed people having issues it has been found when we went through their methodology that they were way off on their heating/soaking procedures



Well-Known Member
Okay, I've gone back and re-read this post about a dozen times, and I guess I'll try 1084 & 5160 in Parks 50 since I have both laying around. For these two steels is there a favorite tempurature for the quench? Room temp. seems a little vague. I like a little more control for consistancy. Parks 50 at 108 degrees just seems crazy fast. Would 75 degrees be a good place to start? Just want to reduce the learning curve here.

Karl B. Andersen

Well-Known Member
Except that when it's been 100 for a week, "75 degree" oil just ain't possible.
The other day I checked my thermometer on my oil tank and it was 98 degrees. With my laser thermometer, I went all around the forge area in my shop and the thermal mass temp of all the objects in the room was 100 degrees in the afternoon.
In the summer, your oil may be well above 75 degrees for two months, depending upon where you live.
For this reason, to have the same results year 'round, I heat my #50 to 100 degrees every time as a constant, and try to deal with consistent austenizing and tempering times and temps as the variable for the individual steels.

I would think that 75 degrees would be fine.