I wanted to do this tutorial with two goals in first one expanding my knowledge on substance painter and secondly I noticed that Tim Bergholz (Chamfer Zone) used a different technique than usual to create the high poly model so thought I could learn it for future productions.
Started by using the reference image provided and began blocking in the blade Topology. I ensured that the middle of the blade was on the 0,0,0 to help get a perfect symmetry without needing to tweak it every time. For the whole part on the blade I created a cylinder and enabled snap to vertex mode and used the cut tool to create the cylinder on the blade mesh. After that I deleted the reference cylinder tidied up the topology. I also extruded the cylinder I created to the middle of the blade to align it with the rest of the mesh.
After the main block out I defined the blades shape further adding the thickness and edge detail in the middle of the blade.
To create the teeth part of the blade I created a cylinder and duplicated it several times while lining it up to the reference image behind. After that I used the boolean technique and fixed the topology errors that went with it.
I used the same technique for the below teeth section of the blade. Moving on to the handle I started with a simple block out mesh I also used the straight handle reference image as I could then later use a FFD modifier to bend it slightly.
I then defined the handle more by adding more subdivisions and also creating the sections for the bolt parts on the handle. I then used a FFD modifier like I said previous to bend the handle slightly.
The image above shows the final low poly with rough mapped out smoothing groups.