Chisels

[titan]

Hello all,

My first post although I have been reading the forum for a while. I am building my own house ( for some time : )
it is an Oak frame and I am now moving on to second fix and beyond. I have a fair amount of Oak sticked drying some of it six years old so I expect the 6 x 6 beams will be air dried by now. I have just bought a bandsaw and planer thicknesser and recently re-sawed and prepared some Oak for a frame and doors for an external meter box. I am ready for making the joints and realise the cheap chisels I have are not really the required quality. I have searched the forum and investigated the popularity of Japanese chisels but find a lot of conflicting information reading the various sites. I like the idea of a harder steel especially for Oak but am put off a little by the possible fragility of the edge due to the brittleness. I have a couple of Sorby heavy duty chisels which have been great on green Oak but don't know whether to stick with Sorby for the finer work or get some Japanese chisels or even two cherries. I am happy to pay for quality tools but the work I have planned is not cabinet work. Any comments welcome.

thanks

Ian

 

[Karl]

Ian

I have the heavy duty Japanese Chu-usu Nomi chisels for larger scale work - see here http://www.axminster.co.uk/product-Iyoroi-Japanese-Chu-usu-Nomi-Chisels-21854.htm

I haven't had any problems with them to date, and I have been extremely pleased with them. I have the 18mm, 24mm and 36mm. No broken edges to date.

Cheers

Karl

 

[matthewwh]

Hi Ian,

I can't be too specific in terms of brands etc as I run a tool business, but hopefully I can clear up the whole hard vs brittle thing for you and help you make a more informed choice.

Pure carbon steel, be it Japanese or Sheffield O1 used by most English makers, becomes brittle when it is hardened. Taken straight from the quench it would shatter if you hit it with a hammer. To exchange some of the hardness for toughness it must be tempered by heating it gently to around 200 degrees, cooler tempering temperatures remove less of the hardness, warmer ones remove more.

RC60 - 61 is approximately the point at which the hardness and toughness balance is optimised and it is this point that most good quality English toolmakers aim for. If you think of it in terms of toffee, there are hard ones that snap like a werthers original, others are really chewy like a toffo and then just occasionally theres one that is right on the sweet spot between the two and will break your teeth and rip your fillings out - this last one is properly forged carbon steel at RC60 - 61. Very easy to sharpen, takes a superb edge and is tough as old boots.

The Japanese laminate their blades with iron, which is largely unaffected by the heat treatment process (in toffee terms it's always chewy). Because of this reinforcing / supporting layer, they can temper at cooler temperatures, leaving the steel layer at RC62 - 63 and still produce a strong blade. It doesn't sound like a lot but it does significantly increase the ability of the steel to resist abrasion, therefore making a very durable edge in terms of wear.

In terms of impact resistance, because the steel is more brittle (like a werthers original) the Japanese use steeper bevel angles to avoid chipping, typically around 33 degrees for the main bevel; English chisels tend to have the main bevels ground at 25 to 30.

At the end of the day, good quality English and Japanese Chisels are both highly evolved solutions to the hard / tough / brittle problem and will knock anything made from spanner metal into a cocked hat. For your selection criteria I would put far more importance on the right blade shape for your work and what feels right and comfortable in your hand than on the internal composition of the blade.

Hope this helps!

 

[WellsWood]

Beautifully descriptive and highly educational Mathew, thank you.

Baby keeping you up then? :wink: :lol:

 

[matthewwh]

Baby keeping you up then? :wink: :lol:

Hi Mark,

How's it going?

The little man has been fantastic so far, bottle of milk and a story at seven o'clock and he's asleep right through 'til seven the next morning. Touch wood! (if you'll pardon the expression).

 

[WellsWood]

Fine Matt, thanks.

PM sent.

 

[Paul Kierstead]

Lovely explanation!

And ...

... and will knock anything made from spanner metal into a cocked hat.

Will get used. Awesome turn of a phrase!

For your selection criteria I would put far more importance on the right blade shape for your work and what feels right and comfortable in your hand than on the internal composition of the blade.

The single thing that seems to be missed the most. Very astute advice, I'd be trying to buy stuff from you if I was on the right side of the pond.

 

[titan]

I have the heavy duty Japanese Chu-usu Nomi chisels for larger scale work I have the 18mm, 24mm and 36mm. No broken edges to date.

Thanks for the feedback Karl.

Ian

 

[titan]

hopefully I can clear up the whole hard vs brittle thing for you and help you make a more informed choice.


At the end of the day, good quality English and Japanese Chisels are both highly evolved solutions to the hard / tough / brittle problem . For your selection criteria I would put far more importance on the right blade shape for your work and what feels right and comfortable in your hand than on the internal composition of the blade.

Matthew,

Thanks for the explanation although I am quite happy with the metallurgy and manufacturing process, my background is engineering but I have read several articles mentioning the real possibility of blade chipping with the Japanese chisels when used for anything other than fine cabinet making. You would think if the best European chisels are using the same steel at a finer bevel they would be more prone to chipping but I have not seen that mentioned anywhere. I was just asking if anyone out there in the real world has seen this problem. I see also some Japanese chisels are now being made from a version of HSS.

Ian

 

[Taffy Turner]

Ian,

FWIW I have the Two Cherries set which I bought from Axminster. I use these a lot in Oak and find them to be excellent. They hold their edge really well. I have never used Japanese chisels so can't offer an opinion there.

If I was buying the Two Cherries set again I would have gone for the un-polished set as advised by others on here (do a search), as flattening the backs was a bit of a marathon on my set.

Regards

Gary

 

[woodbloke]

An excellent analogy of the hardening and tempering process...thanks Matt. Fwiw, I've used the Axminster jap chisels and they've been very good indeed but do need to be honed as Matt has said to a steeper angle like 33deg. I now prefer the A2 LN chisels which also benefit from a higher honing angle of 33deg. The normal 30deg angle that I used to use for conventional English carbon steel edges will simply make an A2 edge crumble...had it happen - Rob

 

[pam niedermayer]

The Atsu and Chutaka are quite strong chisels and intended for carpentry. Couple of other things about Japanese chisels: 1) it's very important to use the proper chisel for the job at hand, not doing so will likely lead to broken chisles and/or wood; and 2) it's a good idea to break in Japanese chisels, take them through a couple of gentle use/sharpening sessions before pounding away, seems that they sometimes need work hardening, tempering, whatever.

Pam

 

[David C]

Pam,

There is a long established consensus in the west, that the best metal is to be found after a few sharpenings or grindings, in all edge tools, as the tip of a bevel cdoes not harden and temper as well as the main bulk.

Toshio Odate's story about sun baking new Japanese plane blades on a hot tin roof is most intrigueing.

I have always found that professional grade Japanese chisels outperform European chisels by a significant margin, but there are some rather nasty cheap ones about which are best avoided.

Matthew,
I have my doubts whether many UK chisels are hardened to Rc 61?

Which ones do you think are please?

best wishes,
David

 

[matthewwh]

Hi David,

I was thinking specifically of Ashley Iles in this case, with RC61 being the aiming point with a slight tolerance below (chewy) but not above (brittle).

The AI ranges that we stock (Bevel Edged, Butt and Dovetail) are all forged O1 and they aim to get as close to RC61 as possible without going over it. In the catalogue they state RC59 - 61 allowing two degrees of tolerance, in practice, when the tools are tested before final grinding they are almost invariably within one degree.

Some makers use slightly different steels which have different optimum hardnesses. The low alloy EN47 that Robert Sorby use in their bevel edged chisels optimises at RC60 so they harden to RC58 - 60 in order to stay just on the tough side of the optimum. Their paring chisels are EN45 because the priority here is to produce a strong springy blade that will hold a very fine edge with the minimal support offered by the 20 degree bevel, hardness is secondary as paring chisels don't generally do enough "wood miles" to suffer from mechanical abrasion. Even so, with the triple tempering they use to achieve the required phenomenally fine grain structure they are still able to achieve a very respectable RC58.

Rockwell hardness merely gives us an indication of resistance to mechanical abrasion, which is only one of many factors to consider in choosing the right chisel. If this is a particular priority, for work in abrasive timbers like Teak, Iroko or Kauri for example, then good Japanese chisels (you're quite right there are some woeful examples out there) and LN's A2 range both score very well in terms of Rockwell hardness, albeit by very different means. In both cases though, this comes at the price of requiring steeper bevel angles to prevent edge failure via chipping or bending respectively. That said, as long as the manufacurers recommended angles are maintained, end users are very unlikely to encounter a problem and with good honing technique both will still take a very useable edge.

 

[newt]

I have read that the Japanese work mainly in softwood, if this is the case does it have any influence on their chisel design?

 

[David C]

Matthew,

Very interesting and in depth answer.

Thank you.

David

 

[MarcW]

Hi all,

I once wrote that Two Cherries are now (then) available only ground and not polished. I bought three of those. I got deceived by flattening the face (side opposite of the bevel) because two of the three had a hollow and were even torn... Other woodworkers confirmed me they too had problems with the ground geometry.

Two Cherry offers an important advantage by producing this unreached range of different sizes, going from 2 mm to 32 mm in 2 mm steps and from 35mm to 50 mm in 5mm steps. If you have imperial sized tools, you could hesitate.

IMHO Two Cherries has an acceptable price-performance ratio. Keeping in mind that they need some fettling. As I don't like the handles, I turned other ones...

For cabinetmaking I'd reach for the LNs or some professional graded japanese chisels.

 

[pam niedermayer]

I bought a small set of 2 Cherries about four years ago from Dieter, when a dollar was worth something , they were only $70 or so, and found them a great bargain. I know nothing about their quality today. Of course, I never really checked for flat backs, simply used them out of the box. Ignorance is truly bliss.

I normally use Japanese chisels for everything, but this set of six allowed me to fill in some blanks on the cheap.

Pam

 

[sparky]

Just a thought here

I thought to to recommend Barr chisels. I have a set of their cabinet makers chisels 1/4"- 1" and they are TOUGH and take an awesome edge very easily and hold it for a long time. Barr makes chisels mainly for timber framing so these cabinet maker chisels are up to any task that your oak would have. They may not be delicate enough to do the finest of cabinet work but from what you describe I thought that I would recommend them. Now with the dollar as weak as it is that might be an advantage but then there are all those taxes that you have for importing. Just a suggestion as I think that you can't beat his quality...he learned metalworking from a japanese sword smith.



http://www.barrtools.com/

sparky

 

[bugbear]

I have read that the Japanese work mainly in softwood, if this is the case does it have any influence on their chisel design?

The Japanese work in a range of woods - their planes are made from very hard (Japanese) Oak.

However, in the west, their Shoji work (in softwood) has achieved disproportionate publicity, leading to a deceptive view.

BugBear