I have often told my wife that if she needs to defend herself the RI 3/8 is the one to grab
I have often told my wife that if she needs to defend herself the RI 3/8 is the one to grab
Ken, I was not referring to your post. A2 comes in for a bashing a great deal for its use in plane blades and chisels. LN and Veritas both use it in their mortice chisels. My comment was simply to let others know that I consider it to be good steel for this purpose, and not to baulk at the offerings from these two companies based on talk on forums.
Regards from Perth
Derek
Ken,
My read of Derek's post made me think not of this thread, but all the other times, in other threads, people talk about A2 steel being a bit chippy at lower angles.
Of course a mortise chisel, no matter what steel of which it is made, shouldn't have a bevel at a paring angle.
A mortise chisel may actually be one tool that works best with a "Paul Sellers" rounded bevel.
My recently acquired 1/4" Narex mortisse chisel seems to be working fine with a flat bevel. It will likely be a few years of use and honing before it gets a bit of a round to it.
jtk
"A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
- Sir Winston Churchill (1874-1965)
That only works if the attacker holds still long enough for her find a 32 oz mallet to drive it in.
Seriously, you want something that will slice what it can and fit into gaps between stuff it can't (trying to avoid being overly explicit). I'd probably reach for one of my skews. There's no need to get fancy.
Pig sticker? What I would use is measured at .45. YMMV.
Mortise chisels 1.jpg
These are my Mortise Chisels, have no idea what steel is in any of them.....not really a concern to me, anyway.
One Japanese, a British Zone German, a New Haven Edge Tool Co. couple of Butchers..and the older, pre Home Despot ones.
another view.jpg
Have since added a 3/8" Witherby to this mess. As long as they do the job I ask of them, fine with me.
Brass!.jpgStarting to get a "collection" of Brass....
Sane opinion here FWIW. A2's limitation is its grain/carbide size, which is larger than either O1 or PM-V11 (but quite a bit smaller than D2). For a mortise chisel we simply shouldn't care about that. A2 is a perfectly sensible choice for that use, as is D2.
Given that you like the D2 RIs I think that you would find PM-V11 to deliver similar performance in that application (though far better performance in other uses that require good edge-taking and chip-resistance). Its composition is broadly similar to D2's, and its maker states that it "can be described as ... a corrosion resistant D2 tool steel". The key difference between the two is that PM-V11 has far finer grain structure than D2 due to PM processing, but that doesn't matter as much for mortising as noted above.
Last edited by Patrick Chase; 02-18-2018 at 4:38 PM.
Jim,
As I posted, a mortise chisel is nothing but a wedge without need for a super keen edge, I agree A2 would be/is a good steel for mortise chisels, I read once why RI picked D2 for his chisels but do not remember why D2 over A2. BTW, I sharpen my mortise chisels with a rounded bevel, gives a natural lever action.
ken
You can very roughly think of D2 as A2 turned up to 11 (or maybe higher). They both derive their wear resistance largely from Chromium and Chromium carbides. A2 has ~5% Cr, while D2 has ~12%. D2 is therefore quite a bit more wear- and abrasion-resistant than A2, but can still be sharpened on the same media because it just contains more carbides rather than harder ones as in M4 HSS or CPM-3V.
Conventionally processed D2 also has much larger grain and worse edge-taking than A2, which is why we don't see it used much in paring chisels or plane irons, but that downside doesn't really matter for a "brute force oriented" tool like a mortise chisel. It has often been said that D2 "takes a crappy edge and holds it forever", and that's more or less what you want in this application. I also read the TFWW article that explained why Ray Iles chose D2, and IIRC it basically came down to that.
Last edited by Patrick Chase; 02-18-2018 at 5:38 PM.
Patrick,
A curiosity question. Do or would you recommend a hollow ground primary bevel on a D2 RI mortise chisel? If so approximately how close to the edge would you get? I realize that depth of cut and choice of wood would probably come into play but just generally speaking.
Chet
I don't put hollow grinds on any thick-section mortise chisels. While my cuts always "ride the back" when mortising, the bevel plays a huge role in ejecting waste out of the cut and also in levering. It seems to me that a straight profile is less likely to cause problems with those functions than one with curvature, so I use a belt- or disc-grinder when I need to do serious work on my mortise chisels.
Note that I am *not* saying: I haven't tried hollow-grinding those chisels, so I don't know that there's a problem. I simply decided that I didn't want to have to worry about that variable.
With that said I don't see any reason why the D2 RI would be unusually problematic for hollow grinding.
Chet, I would not recommend a hollow grind on any mortice chisel, regardless of steel ... well pehaps green kryptonite. A hollow grind will weaken an edge since inevitably the chisel will be used to lever chips. I prefer to use a rounded bevel - easier to freehand.
Regards from Perth
Derek
Thanks Patrick, it make sense about the role a flat bevel will play in ejecting waste. I was just curious, that's all.
Chet
Derek, Thank you, that's why I asked. I thought about trying it but a little voice inside me kept saying "not a good idea"
Chet