Making a Titanium UL Hatchet, advice?

[Jeff000]

I'll start by saying I know Ti isn't ideal. But follow that up with my goal is something I can carry backpacking, and saving weight. I'd really like it to be under 7oz with handle.

I am planning betta Ti, and precipitation hardening. And wrapping the handle with para-cord.
Thinking 4mm thick, and probably strategic weight reduction, I'd like to somehow make the back a little wider so it could be used as a crappy hammer but mostly so you could pound it into a log with another log type thing.

So with the idea of it needing to be light, do I have a chance of it not being useless? It's pretty expensive to fail hard at my attempt, lol.
I am a little worried about it's strength if used like a pry par a bit.

 

[Seth Green]

Mecha can tell you all you need to know about Ti

 

[BitingSarcasm]

You are going to run into several issues. Some random thoughts: I have never met a paracord-wrapped handle that was comfortable for any kind of sustained chopping. If weight is so critical, skip an axe altogether and tape the ends of a saw blade or learn how to baton a smaller tough knife.

Mechanics are also going to work against you. Titanium is amazing stuff, but part of what makes an axe work like an axe is having enough mass behind the edge. I have a tomahawk cut from a big, flat piece of D2, where most of the mass is actually in the handle. It doesn't work as well as a straight chopper as a traditional, wooden-handle hawk. The center of mass isn't at the end of the lever arm, so you aren't getting the kind of mechanical advantage that makes chips fly. I do like it in applications where I need a lot of control in shaping a piece of wood instead of blowing it apart, since I am not cashing in speed for power.

Going light is okay for some things in backpacking, but if 7oz is the limit for your axe, the tool you are going to end up with is probably going to be an axe-shaped object of limited utility. Although it would be incredibly awesome if you push the envelope and innovate something new and exciting.... Like Seth says, talk to Mecha and seeing what he thinks is your best bet.

 

[Jeff000]

You are going to run into several issues. Some random thoughts: I have never met a paracord-wrapped handle that was comfortable for any kind of sustained chopping. If weight is so critical, skip an axe altogether and tape the ends of a saw blade or learn how to baton a smaller tough knife.

Mechanics are also going to work against you. Titanium is amazing stuff, but part of what makes an axe work like an axe is having enough mass behind the edge. I have a tomahawk cut from a big, flat piece of D2, where most of the mass is actually in the handle. It doesn't work as well as a straight chopper as a traditional, wooden-handle hawk. The center of mass isn't at the end of the lever arm, so you aren't getting the kind of mechanical advantage that makes chips fly. I do like it in applications where I need a lot of control in shaping a piece of wood instead of blowing it apart, since I am not cashing in speed for power.

Going light is okay for some things in backpacking, but if 7oz is the limit for your axe, the tool you are going to end up with is probably going to be an axe-shaped object of limited utility. Although it would be incredibly awesome if you push the envelope and innovate something new and exciting.... Like Seth says, talk to Mecha and seeing what he thinks is your best bet.

Definitely interested to see what Mecha can add for sure.
I know paracord wrapped isn't ideal, but this is to make some kindling, early fire wood and stuff like that, not chopping a few cords to heat a house. I do also always carry a pair of cut resistant utility gloves (Just mechanics gloves). I plan on designing something in to make pulling tent pegs out too.
A saw blade and tape would be light, but not ideal. I have a folding gerber freescape camp saw, it has a 12" blade, and is effective, but not at splitting.

The 7oz is just a thought, as that is what my splitting froe weighs, but it can't pull tent pegs, and once it's in as deep as the blade and didn't split then it's a huge pain to get out.
I try and keep weight down where I can, I never realized how much a few oz here and there adds up. Having just this ax and ditching the saw and froe it would save me a half lb.

I'm hopeful that something can come of this, would be interesting.

 

[Mecha]

I'm working on a few ti alloy axe/hatchet things right now, as it turns out.

J Jeff000 As BitingSarcasm says, you'd be best to keep the most of that 7 oz of mass in the head of the hatchet, and put the strategic weight reduction in the handle. Titanium alloys are very strong in real use, and even a heavily skeletonized handle should be fine as long as it's engineered well.

Since ti is light, the hatchet face can be sort of wide and big for it's weight, which may be a plus if you use it to baton like you described, with the logs. There should be no issue at all with batoning ti unless the heat treatment was messed up and it was embrittled. You can upset (widen or mushroom) the back of the hatchet head by heating it up to glowing orange with a blowtorch and carefully beating it with a hammer.

A longer handle will let you whip the hatchet head more quickly which WILL take up some of the slack that the light weight may bring. Other than that, the cutting geometry of the edge can be optimized for a light blade; I like a thin convex, almost flat but the little bit of convexity helps keep the blade from getting stuck in a log during a deep cut, and if the handle is longish then it will cut deeply. No reason it won't work - it will be different, but should be effective for getting things done.

Here are the two big titanium alloy axes / plate 'hawks I'm working on now, a side project. They are still being forged, the cutting faces are being spread out and widened, and beveled. The cutting edges will be heat-treated and hardened. The hafts are going to have somewhat of a diamond section shape when finished. They look like cartoon axes, LOL! The taller one has a 9" wide blade and is 33" long. When they're finished there will be a video of them in use posted here on Bladeforums.

 

[Jeff000]

I'm working on a few ti alloy axe/hatchet things right now, as it turns out.

J Jeff000 As BitingSarcasm says, you'd be best to keep the most of that 7 oz of mass in the head of the hatchet, and put the strategic weight reduction in the handle. Titanium alloys are very strong in real use, and even a heavily skeletonized handle should be fine as long as it's engineered well.

Since ti is light, the hatchet face can be sort of wide and big for it's weight, which may be a plus if you use it to baton like you described, with the logs. There should be no issue at all with batoning ti unless the heat treatment was messed up and it was embrittled. You can upset (widen or mushroom) the back of the hatchet head by heating it up to glowing orange with a blowtorch and carefully beating it with a hammer.

A longer handle will let you whip the hatchet head more quickly which WILL take up some of the slack that the light weight may bring. Other than that, the cutting geometry of the edge can be optimized for a light blade; I like a thin convex, almost flat but the little bit of convexity helps keep the blade from getting stuck in a log during a deep cut, and if the handle is longish then it will cut deeply. No reason it won't work - it will be different, but should be effective for getting things done.

Here are the two big titanium alloy axes / plate 'hawks I'm working on now, a side project. They are still being forged, the cutting faces are being spread out and widened, and beveled. The cutting edges will be heat-treated and hardened. The hafts are going to have somewhat of a diamond section shape when finished. They look like cartoon axes, LOL! The taller one has a 9" wide blade and is 33" long. When they're finished there will be a video of them in use posted here on Bladeforums.

I wonder how skeletonized I can make it, I'll have to play with fusion I'm sure it's got something to test that. I'll be cutting several from wood before ti, hopefully strength is something scalable, maybe mdf, see how light I can make it and load test to find a sweet spot.

Are you cutting yours by hand? I was thinking laser cut to give each edge haz a little hardening and then only precipitate harden the cutting and hitting edge. But maybe waterjet will be better?
With heating it to mushroom the end, won't that really affect the heat treatment?

I have the shape of the blade similar to yours on the right but without the part hanging down. I'll have to play with size and weight a bit. Think going a little thicker and making the head a little smaller is better than a bit larger but thinner head?

Thanks again for the reply.

 

[WValtakis]

I'm working on a few ti alloy axe/hatchet things right now, as it turns out.

J Jeff000 As BitingSarcasm says, you'd be best to keep the most of that 7 oz of mass in the head of the hatchet, and put the strategic weight reduction in the handle. Titanium alloys are very strong in real use, and even a heavily skeletonized handle should be fine as long as it's engineered well.

Since ti is light, the hatchet face can be sort of wide and big for it's weight, which may be a plus if you use it to baton like you described, with the logs. There should be no issue at all with batoning ti unless the heat treatment was messed up and it was embrittled. You can upset (widen or mushroom) the back of the hatchet head by heating it up to glowing orange with a blowtorch and carefully beating it with a hammer.

A longer handle will let you whip the hatchet head more quickly which WILL take up some of the slack that the light weight may bring. Other than that, the cutting geometry of the edge can be optimized for a light blade; I like a thin convex, almost flat but the little bit of convexity helps keep the blade from getting stuck in a log during a deep cut, and if the handle is longish then it will cut deeply. No reason it won't work - it will be different, but should be effective for getting things done.

Here are the two big titanium alloy axes / plate 'hawks I'm working on now, a side project. They are still being forged, the cutting faces are being spread out and widened, and beveled. The cutting edges will be heat-treated and hardened. The hafts are going to have somewhat of a diamond section shape when finished. They look like cartoon axes, LOL! The taller one has a 9" wide blade and is 33" long. When they're finished there will be a video of them in use posted here on Bladeforums.

And why am I just hearing about these now?!

 

[Fmont]

Just say no!

You're going to spend a lot of time and money making my something that will be trashed by the end of your first trip. My advice is to not invest those resources into a novelty item.

 

[Jeff000]

Pe

Just say no!

You're going to spend a lot of time and money making my something that will be trashed by the end of your first trip. My advice is to not invest those resources into a novelty item.

People said that about the 19g titanium trowel I have too, but I've booted it through roots even and it's just like new.

Im not sure why it'd be trashed after a couple nights use though. Do you have any experience or incite?

 

[Hickory n steel]

Food for thought, a Buck 110 weighs about 7oz.
I don't think a 7oz " axe " is going to be anything more than an axe shaped knife that's neither a good knife or axe.
If you are dead set on a titanium axe or hatchet I'd suggest going for a traditional head that hangs on a hickory haft.
You might be able to get something semi useful then.

 

[Jeff000]

Food for thought, a Buck 110 weighs about 7oz.
I don't think a 7oz " axe " is going to be anything more than an axe shaped knife that's neither a good knife or axe.
If you are dead set on a titanium axe or hatchet I'd suggest going for a traditional head that hangs on a hickory haft.
You might be able to get something semi useful then.

But then the handle will weigh more than 7oz alone, defeating the whole purpose

 

[Hickory n steel]

But then the handle will weigh more than 7oz alone, defeating the whole purpose

I suppose that's true.

You really do need to reconsider that 7oz limit though.
There's just no way an axe that weighs less then many full sized leatherman multitools is going to be good for anything.

 

[Mecha]

And why am I just hearing about these now?!

It's just a dumb secret side project, but I bet they'll be fun to use. They're going to get something like a sword edge shape; gonna call them "cutting 'hawks" or something.

I wonder how skeletonized I can make it, I'll have to play with fusion I'm sure it's got something to test that. I'll be cutting several from wood before ti, hopefully strength is something scalable, maybe mdf, see how light I can make it and load test to find a sweet spot.

Are you cutting yours by hand? I was thinking laser cut to give each edge haz a little hardening and then only precipitate harden the cutting and hitting edge. But maybe waterjet will be better?
With heating it to mushroom the end, won't that really affect the heat treatment?

I have the shape of the blade similar to yours on the right but without the part hanging down. I'll have to play with size and weight a bit. Think going a little thicker and making the head a little smaller is better than a bit larger but thinner head?

Thanks again for the reply.

The big ones pictured were cut by hand with a plasma torch, which leaves an ugly, ragged haz and needs to be heavily cleaned up by grinder. A laser will be nice and clean, I bet.

To mushroom/upset the back of the hatchet head, you would need to heat n' beat just the back before the edge was ground. So the flat stock would be standing upright with the cutting edge side down on an anvil, and just the back would be glowing orange. The amount of widening would be pretty minimal but it would work.

After all the shaping and grinding and everything is done except sharpening, that's when to heat treat the hatchet.

As for thick vs. thin, either could work. A thicker one I think would be better for batoning and splitting, and a thinner one would be better for cutting and hacking. Using thicker stock is going to result in more dimension, helping to stiffen a skeletonized handle and offering more ways to tune the cutting head's shape to do what you want.

 

[Moonw]

The head on a Vaughan Sub-zero is 8oz. How much can a small hickory handle weigh?

Did you consider a slip-fit (tomahawk) head that you could use to make a handle for when you camp (assuming you can take your sweet time)? (I don't know one to recommend, though.)

Of course, if you're very fond of a Ti implement, I hope you'll source a fitting one and don't forget to write a follow-up on ths thread. Good luck!

*

Cool stuff, Mecha!

 

[thebrain]

Maybe get a Cold steel Viking hand axe to get a feel for how a really light axe type object would perform for around $35. Weighing around 17oz it is 5oz lighter than the trail hawk. I would bet if you thinned the eye walls, shortened the beard and cut 7 inches off the handle it would be really light.

 

[Moonw]

If he's serious about the weight, he could sacrifice half of the bit's life, then reprofile. More weight saved...ummm...shaved off?

 

[Jeff000]

It's just a dumb secret side project, but I bet they'll be fun to use. They're going to get something like a sword edge shape; gonna call them "cutting 'hawks" or something.




The big ones pictured were cut by hand with a plasma torch, which leaves an ugly, ragged haz and needs to be heavily cleaned up by grinder. A laser will be nice and clean, I bet.

To mushroom/upset the back of the hatchet head, you would need to heat n' beat just the back before the edge was ground. So the flat stock would be standing upright with the cutting edge side down on an anvil, and just the back would be glowing orange. The amount of widening would be pretty minimal but it would work.

After all the shaping and grinding and everything is done except sharpening, that's when to heat treat the hatchet.

As for thick vs. thin, either could work. A thicker one I think would be better for batoning and splitting, and a thinner one would be better for cutting and hacking. Using thicker stock is going to result in more dimension, helping to stiffen a skeletonized handle and offering more ways to tune the cutting head's shape to do what you want.

I was worried plasma and grinder would leave too crazy of a haz and affect any heat treating. I have access to waterjet and laser pretty easy though.
If ti was cheaper I'd make several and beat them up. I think I can cut 3 from the the peice of ti I have, trying to get 3 different designs to try. Maybe grab a slightly thicker piece to try too.

I like your widening idea, think if I can get it to be 27*12mm or so would probably be ideal.

The head on a Vaughan Sub-zero is 8oz. How much can a small hickory handle weigh?

Did you consider a slip-fit (tomahawk) head that you could use to make a handle for when you camp (assuming you can take your sweet time)? (I don't know one to recommend, though.)

Of course, if you're very fond of a Ti implement, I hope you'll source a fitting one and don't forget to write a follow-up on ths thread. Good luck!

*

Cool stuff, Mecha!

There are a few axe heads that are designed to have you use a piece of wood to use, but it's sometimes frustrating enough finding appropriate sticks for a fire as is.

A hickory handle is pretty light, but a few Oz here and few there add up really quickly.

Maybe get a Cold steel Viking hand axe to get a feel for how a really light axe type object would perform for around $35. Weighing around 17oz it is 5oz lighter than the trail hawk. I would bet if you thinned the eye walls, shortened the beard and cut 7 inches off the handle it would be really light.

I made an aluminum axe with a file ground down for a blade and then rivited to the aluminum, it was 9oz total with no hand protection on handle. And it would suck to use for doing much. I'm not expecting this ti hatchet to ever be used for clearing brush or hacking a tree down. But with the AL one I could cut 2*4 with ease, and a 6" log it stuck in with enough bite that I was able to smash it in enough to split. But the AL gave up the fight on that one it just can't handle the abuse, and AL is brutal with vibration.
Im hopeful that titanium will hold up significantly better.

If he's serious about the weight, he could sacrifice half of the bit's life, then reprofile. More weight saved...ummm...shaved off?

Im hoping each outing doesn't cost too much in material loss for sharpening/shaping. I kinda hope it work hardens itself with age a bit

 

[thebrain]

OP I am envious of your access to tools and such. I would love to see how these turn out. Please keep us posted.

 

[Jeff000]

OP I am envious of your access to tools and such. I would love to see how these turn out. Please keep us posted.

I am still learning fusion 360, so it's slow. Lol
I am lucky that my work uses a machine shop for a lot of work and I have a pretty good relationship with the rep that's willing to cut these items for me if I provide the proper files Lol

 

[thebrain]

I have a similar deal at my work for non knife related items mostly. I can borrow a jackhammer, ladders, all manner of saws but I still can't talk my boss onto buying a 2x72 belt grinder, power hammer or anything cool.