The Beginnings of a New Knife
I received a custom order for a Wharncliffe style blade from a client a couple of weeks ago. Together, we worked through several iterations for a design and finally settled on what I think will be a great looking and very functional knife. I chose the name Shard for this design since every good design should have a descriptive name and not a bland number. If this build goes well, I will likely add this design to my selection of custom knife designs. Here's a look at the Shard design:
I had limited shop time last week, but I did manage to get the blade profiled and through the heat treatment process. Here are a few photos of the blade build.
The blade pattern is traced onto a piece of CPM154 blade steel. Some use layout dye when tracing patterns onto steel. I find that a black permanent marker works just fine.
After the blade gets cut out on my band saw, it gets trued up on my shop-built surface grinder attachment to assure that the sides are flat and parallel.
Once the sides are trued up, I grind the blade profile down to within a few thousandths of an inch.
The pivot hole and the thumb stud hole need to be drilled before the blade gets hardened. I use the paper pattern to locate where these holes will go and center punch smalls divot to get the drill bit to register in the right locations.
Next, it's off to the drill press. This pic shows the back side of the blade where the thumb stud gets a countersink to keep the screw head below the surface of the blade.
I make very sure that the drill press spindle is absolutely perpendicular to the table. The pivot hole gets drilled undersized and then reamed to the correct size to keep the tolerances tight.
With the blade profile refined and the holes all drilled, it's time to heat treat the blade. The blade gets wrapped in high-temperature tool foil with double crimps along the open edges. This is to keep air away from the blade to help cut down on decarborization.
The blade now enters my heat treat oven for hardening.
Once the blade has gone through the hardening cycle, it gets quenched between two aluminum plates and compressed air is shot in between to quickly cool off the blade.
For the next step in the hardening process for CPM154, the blade gets a deep cold treatment to transform any retained Austinite. I use dry ice in this little insulated box that I built for that process. Many makers will put the dry ice in acetone or RV antifreeze for this process, but I find that this works just as well without all the liquid mess. The deep freeze is then followed by two tempering cycles in the heat treat oven.
That concludes the work that I was able to get done on this knife. The next step will be to get all the other main parts cut out and start the fitting and refining process. I hope that you will enjoy following along with me on this build. I'm excited to see how this knife turns out. I have some really high hopes for this one.
- Brandant Robinson