Making an awl blade is something I like to do, mainly because I’ve become quite picky about what I like in order to get the best performance and the most consistent stitch.
So before embarking on this particular awl blade adventure, I thought I'd document the process for you so that you can gain inspiration or at least some ideas.
As my workshop is not set up for metalworking, I am perhaps not using the ideal machines or tools, so adapt to your needs as you feel necessary.
Of course, please wear personal protective equipment when working with sharp objects spinning at high speed, especially goggles or safety glasses.
Before making a blade from scratch, much like designing leather goods, I like to create a brief.
The brief:
The steel must be strong, resistant to breaking, chipping or bending under tension.
The shape of the cross section must have a flat spot along the length which helps the needle find the blade during stitching.
The cutting area should only be at the front of the blade.
The blade should be straight without a taper, so that the width of the holes do not enlarge as the blade penetrates further.
The length should be a general purpose 25mm/1’’.
The blade should fit into a collet awl.
The blade should not rotate during stitching thereby throwing off the angle and the stitching.
I told you I was picky, just ask my local tannery, they pull straws to see who serves me!
So moving onto the choice of steel.
My preference for most leathercraft tools is high speed steel or HSS for short.
This type of steel is very common in drill bits where the steel needs to resist high temperatures during use where other steels would begin to soften under such extreme heat - and being tough enough to cut through other metals!
If you are careless, small pieces if steel like awl blades can easily overheat and lose hardness during the grinding process, so HSS is a little more forgiving in that regard.
I have always obtained great performance from this steel whether pricking irons, skiving knives, awl blades or round knives.
So I bought 3mm and 2.5mm steel rods on ebay (links to buy at the end).
These rods are pre-hardened and tempered to around the same hardness as a high quality Japanese sushi knife, so edge retention should be very good to excellent.
To begin proceedings I placed a 3mm wide rod into my collet awl and pressed it in until it contacted the bottom of the collet.
That way during stitching we won’t have the blade suddenly sinking in when things get tough.
The rod has been marked with blue marker so that we can highlight the base of the blade, and where we want to end the blade 25mm further up.
3mm is quite large, but I am making this for larger stitches in thick leather goods.
After trimming to length with a Dremel and a diamond disc, the rod was placed into a drill press for tip shaping.
I like to have blades taper from the tip to the straight sides for about 5mm. This makes it easy to find the slit in the leather made by a pricking iron.
With the rod spinning, I used a Dremel and diamond disk again to shape a gradual taper.
Now that we have the rod cut to length and the tip has been shaped, it’s into the vice for adding the facets to give the blade its shape.
With the first two facets ground down at the front and the rear, it's time to add another four to create the shape.
The idea is to and up with 6 sides like a flattened hexagon. This offers a flat spot in the centre which makes finding the blade easier during stitching, but maintains strength at the same time.
With the rough shape cut out by hand, it's time to move onto sanding and polishing. HSS is a very hard steel so I am using silicone carbide abrasive paper to remove some of the scratches left by the diamond disc.
As I make my way through finer grades of sandpaper, I periodically add more blue marker so that I can see where I am removing material.
Starting to take shape..
Finally, I used a 2000 grit diamond honing plate (not pictured) to smooth all surfaces down before polishing the steel with green compound and a felt disc in a Dremel.
At this point the tip is hair popping sharp for about 5-6mm. The rest of the edge along the shaft of the blade is about 0.25mm wide and polished to a shine - i.e. it's blunt to prevent the sides from cutting a larger hole.
As a demonstration, here is the blade penetrating through 13mm of hard tempered vegetable tanned leather. Considering it's massive 3mm width, it does a very good job:
If you want to know how I made the awl haft (handle) including how to install a quick change collet, click HERE to read the blog post on how to do it.
Thank you for reading and keep your awl sharp!
Supplies:
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@Edward Yes it makes an ideal steel, a lot tougher than I expected too for such a hard steel.
What a great idea. I have been using square and round HSS stock to make gravers for hand engraving metal. I had never thought to make awl blades.