Diamond chisel round corners

[LionCrownLeather]

18 minutes ago, HondoMan said:

Goodness....  Pricking irons are to be used in conjunction with an awl.  One simply makes wee 'pricks' or marks on the leather and then using an awl, sews the two pieces together.  A diamond chisel is ment to combine a pricking iron and awl.  One can punch through both pieces of leather (depending upon the combined thickness). 

You need to spend time watching Nigel Armitage videos to get a better grasp on this topic. 

 

In nigel armitages video he demonstrates with these irons and punches all the way through. 

 

[billybopp]

In nigel armitages video he demonstrates with these irons and punches all the way through. 

He does indeed.  But there are some caveats there.  Pricking iron teeth are "V" shaped.  As a consequence of that, the hole that they make will also be considerably wider on one side than the other.  If the leather is quite thin it's not of much consequence, but with thicker leather it can just be too much.  They ARE designed to be used with an awl, but again, with thin leather it does not matter so much.  

Stitching chisel teeth have a sharp point, but the body of the teeth are more straight sided, making them ideally suited for making holes without an awl.  For that matter, if you want or need to use an awl with a stitching chisel (sometimes necessary due to accessibility in one place or another) you can.  You might want to do that when, for example, you've used chisels for most of a project, but need to sew a pocket into a bag that could not be done before the bag was mostly put together.  You would want the stitching spacing to be EXACTLY the same as the other seams.  Mark it in advance with the chisel, then use an awl to actually make the holes you need.

- Bill

[Tugadude]

Many modern irons have straight teeth with a very gradual taper.  They might be considered a hybrid in that they can function as both pricking and stitching irons.