A2 vs. O1 for high angle blades?

[Mr Brush]

OK - here's one for Rob Lee or Derek.... :rolleyes:

I'm about to buy a couple of extra blades for my Veritas bevel up plane. I've seen a few comments on O1 steel, and understand the differences between A2 and O1 in normal use. By 'normal' I mean bevel angles of 25 or 38 degrees. So far so good.

However, are there any thoughts on the better blade to use for a very high angle bevel (e.g. 50 degrees)?? The force on the cutting edge is higher (judging by the effort required to push the plane.....), so is A2 necessarily the best choice? I've seen another thread here that talked about microscopic chipping of A2 on the cutting edge, so would the high bevel angle make this even worse? I appreciate that O1 requires more frequent sharpening even at lower bevel angles, but would a high angle O1 blade last such a short time (with Aussie timbers) as to be a pain in the rear?

Incidentally, does anyone know if Carbatec keep the Veritas O1 blades yet (not shown in their cattledog), or do they need to be ordered direct from Lee Valley?

Cheers

[Basilg]

I have a Hock A2 blade in my #6 which I have set for a heavier cut, and used to have an 01 blade I used for smoothing, both of which had a bevel of 30 - 35 degrees on the crankier Aussie woods. I have not experienced any problems with the micro cracking on the blade edge on the A2 and it does hold an edge better than 01, but does not cut as finely as the 01 when both are sharp.

I find the M2 blades better than both A2 & 01 but have not tried the high angles that you speak of, I will try a small back bevel on the A2 blade and run this over a piece of Brigalow & see how this works out.

Just to clarify things, when you talk of of a Bevel angle I assume you are speaking of the bevel on the blade, and not the cutting angle, which would be the bed angle plus the bevel angle on the low angle plane.

Regards

[Mr Brush]

Hi David :)

Yup, I'm talking bevel angle on the actual blade. So a 50 degree blade angle, plus the 12 degree bed angle on the plane (bevel up), equals a total cutting angle of 62 degrees.

I have already used A2 blades at this angle, and they seem to cut OK.

I guess my real question is whether O1 blades would cut better/worse under these conditions, and would the high cutting angle increase the rate of wear on the 01 blade to the point that you had to resharpen every 30 minutes ! Obviously this is in the context of local timbers, including the dreaded brushbox.....:oo:

BTW - spoke to Tony this morning. We both agreed that you have a LOT of planes:rolleyes:

[rsser]

A 50* bevel angle puts a lot of meat behind the cutting edge and other things equal that should reduce the rate of wear in harder woods and maybe minimise any concern about A2 blade chipping (assuming any heat treatment softness has been ground away).

And no, tho the ctec website doesn't mention it at least in the case of block plane blades the default appears to be A2.

[Basilg]

John

Hi David :)

[QUOTE]Yup, I'm talking bevel angle on the actual blade. So a 50 degree blade angle, plus the 12 degree bed angle on the plane (bevel up), equals a total cutting angle of 62 degrees.

I just spent a couple of hours playing in the shed. I put a 15 degree back bevel on the A2 blade in my #6, the 01 blade in a wooden plane, and the M2 blade in my 5 1/2 ( increasing the cutting angle to 60 degrees ), and planed a cranky piece of Brigalow, Aussie Cedar, European Oak, Spotted Gum, New Guinea Rosewood, and Kwila. All were set to take a 5 thou cut.

The A2 blade took more effort to push through the timber and cut nicely but not quite as nice as the M2. At first I thought the additional effort was due to the additional width of the blade in the #6. However, I planed a piece of Kwila which was around 45mm or so wide so that both planes were taking a cut of the same thickness and width and the A2 blade still required noticeably more effort. As all blades were sharpened the same, I concluded that the A2 blade was not cutting as well as the M2 or 01 blade
After the initial sharpening all were cutting nicely, and handling the rowed grain in the NGR, the cranky grain in the Spotted Gum, the really hard & cranky Brigalow and the soft & cranky Cedar.


I have already used A2 blades at this angle, and they seem to cut OK.

I guess my real question is whether O1 blades would cut better/worse under these conditions, and would the high cutting angle increase the rate of wear on the 01 blade to the point that you had to resharpen every 30 minutes ! Obviously this is in the context of local timbers, including the dreaded brushbox.....:oo:

At the end of my session the M2 blade was performing as well as when I started, the A2 blade was not quite as good a quality of cut as the M2 but needed more effort to push, the 01 blade was still OK but not as good as when I started, and needed to be sharpened.

I don't have a bevel up plane ( & really need one :C ) If I was buying I think I would go for the 01 but put an order for a M2 blade with Thumbsucker


BTW - spoke to Tony this morning. We both agreed that you have a LOT of planes:rolleyes

Clearly the small congested cabinet containing my Planes, has confused you into thinking that as the cabinet is full there are a lot of planes, :no:when in fact it is simply the cabinet is way too small :U

Besides I think Tony's arithmetic skills are wanting:;

I would love to hear other opinions on this topic
Regards

[Mr Brush]

David,

Your comments re. pushing a high angle A2 blade are interesting - I've found the same, but unlike you have never had any other steels to compare with. I guess at the time I put it down to the fact that an effective cutting angle of 62 degrees is almost into scraper territory, so I'd expect resistance to be higher. Now that O1 is available from Lee Valley, it set me thinking whether this might be a better choice. If I could get M2 in a pattern to suit Veritas BU planes it sounds like it would be the best all round option.

As long as O1 isn't a silly choice, I guess I'll get an O1 and A2 blade from Lee Valley and experiment before deciding which to use as the low angle and which as the high angle blade in a BU plane. Easy enough to take the O1 back to a shallower angle if it doesn't work well at 50 degree bevel.......but much more work changing the bevel angle on an A2 (reaches for diamond plate.....:()

I might try to contact Rob Lee to see if he has any views on this. I'm surprised that Derek has been able to resist this thread thus far...

I now realise that the plan to extend your workshop is solely (sic) to accommodate more planes. The secret is out :D.

Cheers

[rsser]

Whatever works for folks is fine by me.

Terry Gordon advises that you really only need HSS for scraper planes. 62* is some way off that.

Mr B if you'd like a radical bevel change on an A2 iron I'm happy to do it for you. Using a diamond stone might ruin a Sunday ;-} I do a fair amount of this kind of reshaping with HSS turning tools and use a Tormek BGM on a white wheel and finish with a Tormek at 200g grading.

[Basilg]

John

Like yourself I was anticipating at that angle there would be additional resistance, & given that both the M2 and A2 blades had the same angles I was rather surprised that the A2 took noticeably more effort to push, than the M2.

I have not seen any M2 blades other than those made by Paul Williams and Thumbsucker. As far as I can recall Paul did not do any blades for the Bevel Up planes, but I believe Thumbsucker has had a few enquires on his thread for these blades.

The plan for my workshop is primarily to create a workable machinery area, and clean space to do handwork & assemble pieces. It is pure coincidence that this will create additional space to store tools even if they are totally necessary. :B

I don't think the O1 blade would be wasted as those ( very few ) that I have, work very well except on the very hard and cranky grain stuff.

Incidentally I also tried the Scraper Plane ( which does not really count as a plane :D ), which has a Hock 01 blade, on all the wood species this also worked well with just the 45 degree bevel and no hook burnished on the blade.

Regards

[Mr Brush]

OK - I think I'll get an O1 blade from Veritas, and will PM thumbsucker about an M2 blade to suit the Veritas BU planes in the next batch to be made. A2 I already have a couple of.

I can then play around with bevel angles to find what works best for me, while also giving reasonable edge retention. Since all the Veritas BU planes (jack, jointer, smoother) take the same blade, its worth spending a little time on this.

Ern - thanks for reminding me to take a look at Terry Gordon's views on the subject. He has some interesting thoughts on the effectiveness of the 50 degree bevel:-

HNT Gordon - BLADE ANGLES (http://www.hntgordon.com.au/newsletterbladeangles.htm)

The Steve Elliot stuff he links to also looks interesting, and I'll have a more thorough read of it when I have time. Thanks for the offer re. changing blade angles, but I'm about to bite the bullet and get a new CMT Duosharp (Coarse/Fine) to ease the pain....:-. Hope your damaged paw is progressing well :2tsup:

Cheers

[Mr Brush]

David - interesting that Terry Gordon also suggests reaching for the scraper plane on really tricky timber, rather than going to extreme bevel angles on BU planes (see previous link).

Looks like there IS a place for a Veritas scraper plane in my collection too.......but then I'll have to build a bigger plane cabinet......which will need more planes to fill it up.....and so begins the slippery slope :rolleyes:

[rsser]

Thanks Mr B.

Yeah, I use the DMT Duo coarse/fine for rehabbing.

No drama if you're going from acute to obtuse; cuts quickly.

[Basilg]

John

They are both interesting sites and seem to validate the conclusions I reached despite the somewhat agricultural methodology I used. If you are looking at a diamond stone check out Jim Davey's site Jim Davey - Planes and Sharpening - Home (http://www.jimdavey-planes-sharpening.com/default.htm)
He has very competitive pricing

Ern
Thanks for the prompt on the HNT site, I was not aware that Terry had those notes on the site.

Regards