My go to pricking iron the last 4 years has been this one from goods japan:
It is actually a stitching chisel but I have never used it as such. I just tap it lightly and make the holes with an awl just like you would with a pricking iron.
The specs on the iron says that it will make holes 4 mm apart resulting in 6,35 spi. I then bought one with 6 teeth and found out that my old iron was wrongly spaced. It actually had around 4,2 mm
resulting in 6 spi.
A few years ago I bought these irons but never really liked them. It was difficult to get a straight line of holes as the pointy awl did not always hit the center of the slit that the iron makes. Also the slits were very hard to see.
3.85mm Leather Craft Pricking Iron
After I had the chance to try a blanchard pricking iron I realised that the ebay irons could be altered so that they were similar to blanchard. They just need to have the teeth sanded down to make a wider mark.
I tried it with the 2 teeth iron and it seem to work alright. Instead of making the teeth flat in the end it made sense to make them a bit more pointy.
To know how much need to be sanded down I marked it with a marker and scribed a line. The line is not that easy to see
I used a dremel for most of the grinding. I started with this cutting disc and cut as close to the line as I could.
I then used a grinding wheel right up to the line. I had the the iron clamped down on the table:
I was possible to get the teeth to almost the same length:
To even out the teeth I used sandpaper on a flat surface:
The point of the teeth are pretty wide now:
I would like the teeth to be a bit more sharp so I sanded them on the edge of the table:
So they now looked like this:
To get the teeth more pointy I used a sanding drum:
And ended up with this:
As you might have noticed the side of the teeth are rather rough. I did spend some time trying to figure out how to be able to sand them without spending too much time. I came to the conclusion that I needed som kind of slack belt sander to be able to get the sandpaper in between the teeth. As I do not have any kind of belt sander I was hoping that there might be some kind of slim sanding disc for the dremel I could use. Before searching online I look through the small box of accessories for the dremel and on the bottom I found the perfect tool for the job. A small sanding disc!
With this disc it took almost no time to sand between the teeth:
The finish is not perfect and not all the way down the teeth but I dont think that it will effect the performance.
So now for the moment of truth. Does it work? I think so. As you can see the marks are pretty consistent. Also the width, length and hole shape they make are good.
Top: ebay iron. Bottom: Goodsjapan
I found some pictures of marks made by blanchard, amy roke and cmdachong and they are rather similar.
Top amy roke bottom blanchard
cmdachong (M) vs blanchard(VB)
The stitching also looks good here with lin cable 432 in white:
I have always had a hard time figuring out if a pricking actually does something to the stitch or if it is simply a way of spacing the holes. I therefore tried to mark holes with a wing divider:
The stitching to the right is from the ebay iron and to the left holes marked with the wing divider
You see a clear difference. Using the wing divider the marks are not pressed very far into the leather and therefore the edge of each hole almost looks to lay on top of the thread. You could live with the result from the wing divider but using it for any more that a few holes just takes to long and also is not very precise.
The real questions is if some of the high end pricking irons preform better than the modified ebay iron. The marks that they make should be a bit more precise but I dont know how much you will be able to tell. I doubt that it will be 10-20 times better which is what you will pay for the extra precision.
The overall build quality and material choice of the high end iron are without a doubt much higher and will stand heavy duty use. The cheap ones from ebay will most certainly not. If you are a full time leather worker then the price could be justified. If you are a hobby leather worker you should consider spending your money on tools that will actually make a difference.