# Mortise chisel angles.



## garywayne (23 Oct 2006)

I picked up a mortise chisel at the car boot sale.

Do I sharpen it with the same angles as other chisels, or, do they have an angle all there own?


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## Philly (23 Oct 2006)

Gary
Normally you grind them at a higher bevel angle-try 30 degrees or higher.
Hope this helps
Philly


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## garywayne (24 Oct 2006)

Thanks Philly.

That is a big help.

I didn't want to go by the angle already on the chisel, because you don't know if who had it new what they where up to.

Also, I have never seen anything regarding the grinding angle of mortise chisels.

Thanks again.


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## Anonymous (25 Oct 2006)

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## Joel Moskowitz (26 Oct 2006)

THe historical standard on Ehglish oval bolstered mortice chisels is to grind the primary bevel at 20 degrees - this gives you penetration. Then put a small secondary bevel at 35 or so degrees. This gives you strength. 

A single bevel at either will either not have the penetration or be too weak. 

TYpcially the primary bevel was hollow ground on very large diameter wheels - but I have done it on regular 6" wheels. it all works but of course without the secondary bevel the chisel will bend or snap.

- I should mention that sash mortise chisels - which are considerable lighter in duty are mostly sharpened with a single bevel at about 35 degrees. But being sash mortise chisels they originally were designed for chopping mortises in window sashes -(shallow and softwood) - the the penetration angle isn't needed.


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## Philly (26 Oct 2006)

Joel
Welcome to the Forum!
Philly


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## Alf (26 Oct 2006)

Welcome, Joel. Good to see you here. 

Cheers, Alf


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## Anonymous (26 Oct 2006)

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## garywayne (26 Oct 2006)

Thank you people, for your response.

Joel, (welcome to the forum), and Jacob, I think that I will give both of your ways a try, and see which one feels right for me, and go from there.

Thank you all again for your input.


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## bugbear (26 Oct 2006)

A rounded bevel all the way from shaft to edge is discussed in reasoned detail in Leonard Lee's book (IIRC)

BugBear


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## Joel Moskowitz (26 Oct 2006)

Mr_Grimsdale":1zozpy8e said:


> I was taught to hone at 30 deg (on an oil stone) ......
> I always assumed "sash" mortice chisel meant a 1/2inch chisel, this being the most common size of a sash mortice and hence the one most used mortice chisel in general. . I wonder if they were termed "sash" chisels and intended for mortices in glazing bars, where a heavy firmer chisel is better for the job - the OBM being too thick for the hole.
> 
> cheers
> Jacob



I think 30 degrees is way to high a primary bevel - but many people do use the rounding motion you describe ona much lower primary bevel. Sash Mortice chisels were specfically designed for shallower mortices in windows and have usually a single bevel and parellel sides. THe window making market was huge and much bigger than the cabinetmaking market


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## Anonymous (26 Oct 2006)

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## Joel Moskowitz (26 Oct 2006)

Mr_Grimsdale":3pt8raxy said:


> This would be the answer to the question of why tool makers make heavyish firmer chisels and call them "mortice" chisels; they are actually "sash" mortice chisels designed for the smaller mortices i.e. not always shallower, but smaller cross- section. Just an idea.
> 
> cheers
> Jacob



It's not the tool makers who mis-name the chisels. As far as I know every maker of registered chisels calls them just that. Sash Mortise chisels look different. It's the tool retailers some of them mis-label registered chisels as "registered mortise chisels" so they have a cheaper lighter duty thingie that people can sort of use for mortising. But it' s a recent phenomena - you don't see it in pre-1970 or 80 catalogs. 

Sorby I tihnk is the only current maker of real sash mortise chisels. They also make registered chisels, and heavy duty sash mortise chisels. They got the names all right in their catalog. It's some retailers who cause the confusion. Heavy duty sash mortise chisels are used for regular mortising but really come from the European tradition, not the English tradition which use Oval Bolster chisels for the purpose.


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## Anonymous (26 Oct 2006)

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## JesseM (26 Oct 2006)

Joel Moskowitz":3jyzi4gs said:


> Sorby I tihnk is the only current maker of real sash mortise chisels. They also make registered chisels, and heavy duty sash mortise chisels. They got the names all right in their catalog. It's some retailers who cause the confusion. Heavy duty sash mortise chisels are used for regular mortising but really come from the European tradition, not the English tradition which use Oval Bolster chisels for the purpose.


So I have a set of Sorby mortise chisels with the boxwood handles. I looked at the website I ordered them from a long time ago, and they still have them, but they are not labeled registered or sash. Are these the heavy duty sash mortise chisels?


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## Joel Moskowitz (26 Oct 2006)

Boxwood handles means that they are probably the sash mortise chisels. 

the Sorby heavy duty mortise and their registered chisels have ash handles.


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## Frank D. (26 Oct 2006)

In France mortise chisels are usually ferruled. Bolstered chisels are typically English. Here's a typical French mortise chisel, quite like German pattern chisels:


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## JesseM (26 Oct 2006)

The Sorby's don't have ferrules which would make think they are not heavy duty, but the LNs don't have them either. Would the LNs be considered sash mortise chisels?


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## Anonymous (26 Oct 2006)

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## Scrit (26 Oct 2006)

Mr_Grimsdale":1qy7xlf2 said:


> The ones I saw in a market in Vaison la Romaine were most definitely the ordinary OB or pig sticker pattern. Of course I don't know how they got there - could have been abandoned by a wandering Brit joiner but they sort of looked local.


The Sheffield firms were early off the mark in the export market (Mathiesons, for example, was very active in South America of all places according to some of their catalogues), so they might have been Sheffield-made, or local copies of Sheffield-style tools. The "English" pattern hand saw, for example, has become pervasive in many parts of the world (or at least Europe), after all, and many European firms copied later American designs such as the Stanley Bailey plane. Or was it perhaps "war booty" from the 1940s?

Scrit


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## Joel Moskowitz (27 Oct 2006)

Frank D.":1at1zatf said:


> In France mortise chisels are usually ferruled. Bolstered chisels are typically English. Here's a typical French mortise chisel, quite like German pattern chisels:



THese would be considered heady duty sash mortise chisels in English terminolgy


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## Joel Moskowitz (27 Oct 2006)

JesseM":1w10rse0 said:


> The Sorby's don't have ferrules which would make think they are not heavy duty, but the LNs don't have them either. Would the LNs be considered sash mortise chisels?



I think you mean hoops - not ferrules. Ferrules are the thing next to the bolster near the chisel blade. 

Sorby sash mortise chisels has bolsters no hoop.

Almost all H. D. Sash mortise chisels have ferrules and hoops - meant for rough work with steel hammers.

But cabinetmakers used Oval bolstered mortise chisels which are by far the strongest and have neither ferrule or hoop - but you must use a wooden mallet. They are also trapaziodald in section for fast deep chopping without getting stuck.

secret: always use a mallet that is softer than the handle of the chisel (any style chisel). It's easierand cheaper to replace a mallet than replace a chisel handle. 

the LN "mortise chisels" are versions of American Millwright and mortise chisels and are parallel ground like sash mortise chisels.


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## Frank D. (27 Oct 2006)

Joel,
I know the hoop is at the striking end of the handle, but on the chisel I showed I thought that the blade was braced by a ferrule, not a bolster. I could be wrong...
Here's a pic of a few mortise chisels; the top one has a ferrule, the next one down has a bolster, and the bottom 2 (which I bought in France) have a ferrule that mate with the wide shoulder of the blade. Aren't bolsters usually forge welded or fitted on to the shoulders of the blade like in the second chisel down? I thought ferrules are a thin sleeve that go up and around part of the handle, unlike bolsters. At least that's my understanding. In France the bottom two are called "bédane à double virole": double ferruled mortise chisels (one of the ferrules being the hoop). I'm not trying to prove anything here, just throwing this out for discussion...


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## Joel Moskowitz (27 Oct 2006)

Both of the french chisels have bolsters - just not hulking big welded on ones like an Oval bolstered English mortise chisel. Actually almost all chisels have bolsters of various sizes or over time the chisel will be driven up and split the handle. These particular chisels look more like sash mortise chisels to me than full sized mortise chisels designed for furntiture or more commonly doors. But I know very little about Continental tool evolution so I can't be certain that actual application or nominclature.


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## bugbear (27 Oct 2006)

Mr_Grimsdale":jpk1vh10 said:


> Should have checked whether or metric or imperial.



I don't think mortise chisels are ever accurate enough for to use that to tell.

e.g. telling the difference between an 18mm chisel and a 3/4" chisel requires better accuracy than mortice chisels (IME) are made to.

I have marked mortice chisels that show a healthy disparity between marked (norminal) size and measured size.

BugBear


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## garywayne (27 Oct 2006)

You have totally lost me, but I have got this one:-
















Sorry about the picture quality. (Cheap camera).

It has been ground to a straight 24deg.

What I don't understand, is that it's measurements are in imperial exept the width of the blade, which is metric.


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## MikeW (27 Oct 2006)

Hi Gary,

Is it 10 mm at the tip of the blade?

In any case, I think that's making BB's point. Other than one or two mortice chisels, I have yet to use a micrometer--even ones which read in imperial or metric units--and arrive at the stated width. 

In the scheme of things, "nominal" width mortice chisels are fine as the gauge is set from the chisel and the tenon marked from either the same gauge or the resultant mortice.

Where it gets to be a slight problem is plowing grooves "needing" to be the same width as the mortice as plow blades seem to be much more accurate in their measurements.

Take care, Mike


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## garywayne (27 Oct 2006)

Sorry Mike.

Yes, 10mm at the tip of the blade.


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## Alf (27 Oct 2006)

Probably intended to be 3/8"


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## Anonymous (2 Nov 2006)

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## garywayne (3 Nov 2006)

Thanks Jacob.

That was an exelent link.


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