# O1 or A2?



## BZawat (Sep 21, 2012)

I just picked up a type 9 no 5 1/2 that's a total rust bucket for like 25 bucks. The iron only has about 1/4" of life left in it, and I got it cheap enough to warrant a good replacement blade. 

Decided to go with a Hock iron, which they offer in high-carbon O1 tool steel, or cryo treated A2 tool steel. According to hock's site, the O1 sharpens better & easier, and the A2 has better edge retention but is harder to sharpen. 

I'm leaning toward the O1, as I usually do a touch up honing before starting a project anyway, but I thought I'd get some opinions. Anyone have a preference?


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## tc65 (Jan 9, 2012)

Most of my planes have old steel, but I do have a Veritas low angle smoother with an A2 blade and I just bought a replacement blade for my jointer with the PM-V11 metal. I haven't done any direct comparison between the different metals on the same plane, but my impression is that the A2 edge does last longer than my older steel.

The A2 does take a little longer to sharpen/hone, but it is not a big deal for me. If you had a number of them to sharpen all at once you might get tired of the extra time, but otherwise sharpening is not a factor in my mind. 

The better edge retention is a big deal to me. On some projects, I'd need to touch up blade in middle of job. I've not had to do this with the A2 blade. Maybe it's perception because I know it's an A2 blade, and maybe it's because the low angle smoother is such a joy to use. I don't know for sure......

Bottom line - Have you ever needed to touch up a blade in the middle of a project? If so, the A2 blade may be the way to go. 

If you touch up before the start of projects anyway and usually don't feel the need to sharpen before project is done then O1 should be just fine.


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## acowboy (Nov 20, 2013)

I was considering a hock blade set-up myself for a older Stanley myself,
this might interest you.
http://www.pm-v11.com/Story.aspx
PM-V11 looks interesting for a replacement.


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## BZawat (Sep 21, 2012)

I looked at the PM-V11 blades, but the 5 1/2 that its going on is an old one & needs a 2 1/4" iron, which lee valley doesn't offer.


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## MarkE (Jan 29, 2014)

You really can't go wrong with either O1 or A2. 

The O1 irons seem to keep their edge longer than the old steel irons, IME. They are very quick to sharpen and you can get a razor edge on them pretty quickly.

The A2 hold the edge a lot longer. They take a couple of minutes more to get sharp, and don't seem to get to that razor sharp sharpness.

My take on it is this. The O1 irons will get razor sharp, but start to dull after several strokes and continue to dull until it is time to re-hone. The A2 start off not quite as sharp, but they don't dull as quickly. The advantage of the O1 sharpness quickly goes away as the edge gets rounded over until it is less sharp than the A2, which continues to be sharp enough for a lot more strokes.

In case it isn't clear, I prefer the A2 over the O1. I actually prefer the PM-V11 over both, but that does not seem to be an option for you with this particular plane.


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## Dave Paine (May 30, 2012)

I do not have any O2 blades so I am not able to compare.

For my new planes and replacement blades I purchase A2. I wanted the potential for longer edge life. The blades all perform well, although I do not do a lot of hand planing on a given project.

I recently purchased a PM-V11 blade just so I could compare. Works well, but I read not an option for you.

I think the Hock and Veritas blades are very good. I think you will be happy with any decision.


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## Gilgaron (Mar 16, 2012)

I had the Veritas pullshave on my birthday wishlist and my wife asked which blade type I would prefer if someone were to want to get me such a thing... (ended up being my mom, my wife got me the router plane  )

So... to answer her question I did some light googling, and near as I can tell from what I read, there won't be much of a different noticeable to most people. So while academically there's a difference, the fellows on some knife making forum I read (grain size of the steel etc was discussed) seemed to think it was all splitting hairs; some picked based on liking the sound one or the other made while being sharpened better. I used that I sharpen by hand to lean me towards O1, semi-arbitrarily. From what I read you should be happy with any of the premium metals.


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## Priusjames (Jan 13, 2014)

Just wanted to mention that this thread is timely for me...I'm currently waiting for a package with several presumably older planes (and other contemporary goodies) from Vermont. I'm trying to remain optimistic they will be complete and ready to work with a little sharpening. A guy can dream...

Questions I won't have until next week have just been addressed, and I've added to my knowledge base. 

Thanks!

Nice day for it, should be nearly 80 degrees out today.


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## BZawat (Sep 21, 2012)

Thanks for all the input, guys. I decided to go with the O1, because I do 90% of my sharpening freehand on sandpaper and I figured ease of sharpening would be a good benefit. I enjoy honing, and if it keeps an edge longer than the old steel I'm used to it will be a bonus anyway. I'll be sure to report back once the plane is restored & cutting.


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## Wema826 (Jul 22, 2012)

Here are links to Mr Cohen's site, he did a heads up comparison of different metals. he used chisels but im sure it would have the same results in plane blades as well.

http://www.inthewoodshop.com/ToolReviews/ChiselBladeTesting-5Steels.html

http://www.inthewoodshop.com/ToolReviews/ChiselParing.html

http://www.inthewoodshop.com/ToolReviews/FourChiselSteelsCompared.html
Interesting results I think.


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## BZawat (Sep 21, 2012)

Awesome thanks for the links John. Great info


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## Tom King (Nov 22, 2013)

I think Derek's test was using some sort of abrasive wood that I've never even seen. O1 and I are old friends. not exactly an abrasive wood, but we recently planed a set of steps with a number three. eight steps, eight feet wide with risers. I sharpened before we started, and didn't have to stop to hone. they were on an old house, and the iron was ground to match other plane marks used in that house. the pine was treated that I had drying for a couple of years.


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## Tilaran (Dec 22, 2012)

My shop is filled of A2 and 52100.
Use D2 for your project.


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## tc65 (Jan 9, 2012)

I know you've made your decision on blade type, but I remembered this link from Veritas which details the testing they did when they were developing the PM-V11 metal that they offer in addition to the O1 and A2 blades. Not meant to sway anyone, I just thought including it in this thread would provide more resources for anyone looking at blade decisions in the future.

http://www.pm-v11.com/#


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