Mortise Chisel Brand

[fritz eng]

Looking for a brand(s) of mortise chisel where its sides are perpendicular to the back. Most mortise chisels i have seen have its sides tapered. Thanks

[Joe Bailey]

Looking for a brand(s) of mortise chisel where its sides are perpendicular to the back. Most mortise chisels i have seen have its sides tapered. Thanks

I understand what you're looking for, but wonder if you're aware of the fact that the old pigstickers were made trapezoidal in cross-section for a reason -- if the chisel was not perfectly perpendicular to the mortise, there was less chance of damaging the wall.

You're much more likely to find a sash chisel ground in the way you've specified, but those are for a different and lighter sort of work.

All that having been said, I seem to recall that Two Cherries brand mortise chisels were made per your spec.

[Marty Gulseth]

I have some Two Cherries chisels, I went out and checked. Sides on those are very slightly beveled - maybe a couple of degrees. OTOH, I have some "Stormont" (Oxley?) chisels, sides on those are as perpendicular as I can tell with my tiny square.

Marty

[Derek Cohen]

Looking for a brand(s) of mortise chisel where its sides are perpendicular to the back. Most mortise chisels i have seen have its sides tapered. Thanks

LN and IBC have parallel sides.

Regards from Perth

Derek

[Mike Allen1010]

I understand what you're looking for, but wonder if you're aware of the fact that the old pigstickers were made trapezoidal in cross-section for a reason -- if the chisel was not perfectly perpendicular to the mortise, there was less chance of damaging the wall.

You're much more likely to find a sash chisel ground in the way you've specified, but those are for a different and lighter sort of work.

All that having been said, I seem to recall that Two Cherries brand mortise chisels were made per your spec.

+1 , well said Joe

[fritz eng]

Thanks for all of this good info guys! Best wishes.............

[Warren Mickley]

One of the reasons for the front to back taper is to ensure that bevel side is not wider than the cutting edge. If the bevel side is wider the chisel will get wedged in and bind. If one can only grind the sides to within say two degrees, then you need to build in a taper to make sure that is not a problem. Some of today's mortise chisels are machined to rather good tolerance, so taper is less necessary. And most woods have some bit of sponginess, so that there is some leeway there also.

The sides of the chisel keep the chisel jigged in the cut, so the taper ought to be as small as possible so that works well. If the four edges along the sides of the chisel are sharp, they scrape the sides of the mortise, and also help to keep things true. This action works best with little or no taper.

[Assaf Oppenheimer]

I recently saw a video by Rob Cosman where he demonstrated the benefit of a square chisel.
you can use a fence to guide it in perpendicular to the work piece and prevent crooked placement of the chisel in the mortise.

seems like a great benefit if you are jig orientated, but only in areas clamps can reach

[steven c newman]

Have 4 from Narex. Have one 3/8" by Witherby, and have 1 from Okinawa/Japan, 12mm.

Plus a couple OLD Buck Bros. Sash Mortise chisels..along with a Butcher, or two. Shop is an EOE.

[J. Greg Jones]

I recently saw a video by Rob Cosman where he demonstrated the benefit of a square chisel.
you can use a fence to guide it in perpendicular to the work piece and prevent crooked placement of the chisel in the mortise.

seems like a great benefit if you are jig orientated, but only in areas clamps can reach

I too saw Rob’s video and I’ve never tried this myself, but I don’t think the sides need to be square to the back for this to work. I’ve seen Paul Sellers do this for years and he doesn’t use mortise chisels-just his bevel edge bench chisels.

[Jim Koepke]

Measuring my mortising chisel the taper of the side was found to be as low as 0.003" on a 3/8" Newbould branded chisel to 0.055" on a 1/2" THOs Ibotson & Co branded chisel.

They all seem to do a good job.

jtk

[Assaf Oppenheimer]

I will say Derek Cohen had an excellent technique on his site:
First he marks the tenon layout on all 4 borders, then he then pares out the waste created by using the mortise gauge and the marking knife lines. This creates a shallow tenon (possibly a 1/16" deep?) perfect for chisel registration.

[Charles Guest]

The whole trapezoidal thing is fine, if done deftly, but it also has a risk of being overdone. It's like hearing that one aspirin a day is good, then three a day must be even better. Decidedly not.

If you can SEE the trapezoidal shape by looking at the chisel at eye level, head-on, it has been vastly overdone. If you put a small square on one, there should be the barest hint of light suggesting relief. If some manufacturer makes a claim as to the exact degree to which the chisel has been relieved then do not buy. The chance that they're hitting that number day in and day out is remote. Problems occur when the chisel hasn't been relieved equally on both sides, and/or has been relieved too much. You'd work just as effectively, maybe even more effectively, with a plain straight-sided firmer for the amount of mortising you're likely to do.

No chisel, regardless of the manufacturer's intention, is ever a perfect representation of flat, square, trapezoidal, or whatever they intended. There's a +/- tolerance in everything. I'd put my money on most being able to get closer to square on a regular basis than a trapezoid. But I'm a cynic by nature. As woodworkers and by necessity occasional metalworkers, we're more equipped to move something back closer to square if necessary than we are back to a properly oriented trapezoid (not "clocked") in relation to the rest of the chisel or handle of the chisel.

Fair disclosure: my mortise chisels are trapezoidal in shape. I rarely use them though because of bursitis in my elbow, an elbow that was also shattered in an automobile accident decades ago. I drill and pare. When I did use them a lot, I was not in love with them.