S7 tool steel machete

[sepukacheekray]

First things first. I have no idea what I'm doing. I can fabricate, but this will be my first machete. This is also my first guide post. and my first post to this forum. Lotsa firsts!

I have a friend who lives in Hawaii, and has trouble with the bush there eating machetes. If the thick vegetation doesn't get em, then the salty sea air will. I have made decorative swords and knives from spring steel in my spare time to stave off boredom, so he approached me to make him a machete that would withstand the harshness of the Hawaiian jungle. Now, seeing as he's a ride or die kind of homie, I'm pulling out all the stops. This may be the most impractical thing on God's green earth, but what the heck, I'll have fun making it.

I chose to go with S7 tool steel because of it's high impact resistance, high durability and good corrosion resistance. It won't hold a razor's edge, but he won't need that since its a bushwhacker. Gonna grab a 5/32"x4"x36" piece of flat stock. It is expensive, but hey, he's helped me and my brother out tremendously and he deserves it.

Here is my initial design sketch. I want the wider blade at the end so it can be used like an axe with the added weight, for the extra tough growth out there like guava. The blade on the backside will work similar to a billhook, for harvesting sugar cane or cutting up smaller brush. this will have a finer edge on it than the front.

The dimensions are still up in the air. until I order and receive the materials and can start mocking things up I'm going to leave them flexible. maybe someone will have a better idea than I do.
Blade Length: Somewhere between 16"-20" (he's a big guy, a heavy machete won't phase him)
Blade Thickness: 5/32" (do I need thicker?)
Blade width at widest point: 4"
Grip length: 6" (I think)

I'm going to make this one a full tang machete, for obvious reasons. I will carve the handle from two scales of black and white ebony, and rivet them to the tang. The tree is called Ciricote, and it looks absolutely yummy. They say it polishes up to a glass smooth finish, but we shall see if I can bring it out of the wood. As far as some kind of sealant or polish, I'd like to stay natural with something like linseed oil. I'll leave a little hole back there for a wrist strap, maybe made of leather or paracord. I can't decide. Maybe I should go with some kind of exotic leather? who knows?

I will have to harden and temper the blade. My friend has an oldschool forge, with crank billow and everything. I will try and use this to heat the metal to between 1700 and 1750 degrees Fahrenheit. I'll be using my handy dandy harbor freight infrared thermometer to keep track of the temperature. I will then let it air cool before double tempering it in an over at 400 degrees Fahrenheit.

The I plan on having his last name laser engraved on one side of the blade. I want it quite big, and easily legible by his enemies at a distance. I'm sure it will strike fear in their hearts.

Finally I want to send the blade off to be coated with aluminum titanium nitride for a beautiful black finish, and to add that extra overkill of corrosion and wear resistance. This will be one expensive beast of a beast.

Ideas, thoughts and comments before I commit to ordering the raw materials? Thanks for having me on your forum, and I look forward to more posts!

 

[Lycosa]

Gonna be badazz...
rolf

 

[Lorien]

looks like about 14" of blade, which is a good length for many things, especially with a sharp spine. The pokey bit might cause issues with a scabbard, and more importantly with safety. As a general rule, I tend to shy away from sharp spines on work knives of this size, including saw teeth.

 

[me2]

Just a couple suggestions. If you are determined to use S7, send it out for heat treating. It will be pretty tricky to get good results on an air hardening stee in a forge, as these steels typically require a soak at temperature of 30 minutes or so. If you are determined to use a forge, perhaps a different steel would be better. Some 1084, 1075, or even 15n20 would be good, though the latter might be hard to find thicker than 1/8".

Which leads to my second comment. What kind of grind are you planning? I have an S7 machete in my garage with a straight 10 degree per side edge from full thickness of 0.135". It doesn't cut very well with that geometry, so I'll probably add a 3 to 5 degree primary grind behind the 10 degree edge grind.

Third comment is on the coating. I don't know the temperature required for the coating you're planning to use, but your tempering temperature should be higher by about 25 degrees. My S7 machete was tempered at about 400 as well, and has good hardness. If you are determined to use that coating and its application temperature exceeds 400 degrees, you may want to consider a different steel or understand that your final hardness will be dictated by the highest temperature used after quenching.

 

[i4Marc]

One thought: Have you considered Cerakote for the finish? it comes in a bazillion colors, is extremely tough, can be formulated in a variety of finishes from matte to semi gloss, and it cures in an oven at 250˚ which will not ruin your temper. Have it applied professionally.