What's going on with these here mortice chisels?

[JoeS]

Based on reading on here I decided to buy a couple of Japanese morticing chisels to try out on a Sedgwick mortiser which I inherited and has sat in the workshop corner for a hundred years.
The issue seems to be though that the shafts of the drill bit part of the chisel is too long for the Sedgwick.

Is this a common problem or have I just bought the wrong damn mortice chisels? Added some side by side pictures of the new chisel next to an old blunt one, and as it sits in the machine.

 

[XTiffy]

Looks like it would be possible to cut the shaft to the same length as the old one.

 

[RobinBHM]

the drill shaft often has to be cut down

make sure the diameters work

also if the drill bit is held with an allen key, grind flat on it or it will spin round

 

[Thingybob]

Had the same problem with my record Mortiser had to have have them shortened by a friend who has a lathe also had the 16mm one s shank reduced to 10mm to fit in chuck but all work fine since shortened them using a metal cutting disc in my angle grinder but 16 mm ones still need turning down

 

[Noel]

Hi Joe, always cut the exposed auger length to suit the machine.

Good guide here which mentions auger length https://www.woodreview.com.au/tools-and-equipment/hollow-chisel-mortisers-use-and-maintenance

 

[paulrbarnard]

What makes them Japanese? Simply country of origin or do they have specific characteristics like with saws, chisels, planes and workbenches?

 

[niall Y]

They are supplied oversized and have to be cut down to suit your machine which is a simple enough task, When I got my Sedgwick morticer I also had an additional two collets made to accommodate the different diameters of chisels I already had, which greatly broadens ones options.

 

[JoeS]

They are supplied oversized and have to be cut down to suit your machine which is a simple enough task, When I got my Sedgwick morticer I also had an additional two collets made to accommodate the different diameters of chisels I already had, which greatly broadens ones options.

How would one go about cutting them down if I don't have a metal working lathe?

 

[JoeS]

What makes them Japanese? Simply country of origin or do they have specific characteristics like with saws, chisels, planes and workbenches?

They were really expensive. That's what.

 

[niall Y]

What makes them Japanese? Simply country of origin or do they have specific characteristics like with saws, chisels, planes and workbenches?

They have a deep single spur and point on the auger. By contrast, the Ridgeway ones have two shallow spurs and a very small point The geometry of the twin helix that clears the swarf is more regular on the Ridgeway ones. The Asian style ones, including those made in Taiwan and China have a more cone like profile to the single helix

How would one go about cutting them down if I don't have a metal working lathe?

A hacksaw as the shaft is not usually hardened. Failing that an angle grinder with cut off disc.