Help with a couple designs (single edge dagger and dive knife)

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Jun 5, 2012
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So I got my first two commissions, and they are both doozies. I think I have the technical ability to pull them off, but I'm not quite as confident to barge in as I was on my simpler designs. Luckily they are both for good friends, and they are both understanding of what they're asking me to do. They're also both willing to wait patiently while I work these on my bench in between knives more suited to my skill level, so that I can give them the time they need to come out nicely.

Right now I have some .152" S35VN that I plan on using for at least the dagger, but maybe the dive knife as well. The dagger customer specifically requested that it be thick and heavy, so I'm trying to make a compromise. I don't think that I can go much thicker than that in this blade size and still come out with an attractive blade.



I'll start with the dagger first. A good friend had a knife similar to this that was important to him and was stolen. We sat down in my shop and did a police sketch style session in which I attempted to recreate his knife from memory. I tried to talk him out of the blood groove (not generally a huge fan) but he insisted, as it was a feature on the original knife, so I didn't push farther. He said the proportions look nearly perfect, so I suspect that the original was a sabre/scandi type grind.

I have the ability to do the groove on my milling machine so that isn't an issue. He originally requested full tang, but I think I may do a full takedown design with a hidden nut in the pommel. I think he is primarily worried that it is very strong. He is a firefighter and there's a good chance this knife may get some pretty heavy use. I'm going with 416SS for the guard and pommel, and black G10 for the handle.



The dive knife is for a good friend that is getting his scuba cert right now. Similar to the dagger customer, he requested a high end stainless steel, so I figured the S35VN I already have is perfect for the job. He wanted a safety tip with one side serrated and one side straight. He also suggested a rope cutter (basically a gut hook), but I don't know that it's necessary with good serration. It is a pretty common feature on dive knives though. This one is getting black G10 for the scales, similar to the one above.

I've never done serrations before, but am reasonably confident that I have the tooling here to pull it off professionally. I think my main concern is the blade thicknesss. I'm not working in such tight quarters as the dagger above, but I don't know if .152" is pushing it for a 1" wide dive knife blade. FYI the grinds will be done on a 10" wheel, so it will be a slightly hollow double grind.

Htznjnt.jpg
 
If you want a good stainless steel for the dive knife try n680 or even better m390.
 
As a (former) sport diver, I like the profile of the dive knife. Put some serious thought into sheath retention and attachment. There are a lot of knives on the bottom of the ocean due to lousy sheaths.
 
As a (former) sport diver, I like the profile of the dive knife. Put some serious thought into sheath retention and attachment. There are a lot of knives on the bottom of the ocean due to lousy sheaths.

I second this... there are three in the Pacific that belong to me, also you may want to consider a lanyard hole in the grip my cousin lost one right out of his hand!
 
There's a super corrosion resistant stainless called N360, I think alpha knife supply might have some in stock. I personally wouldn't go thicker than .125 for a 1 inch tall blade. I like the shape of the dagger, I would round the back of the dive knife a little bit to give it some flow.
 
made my ladys dive knife in Ti for no rust and high toughness. and let her know that its sharpness would only be good for a few cuts (style is a dagger )
i like the dive knife you have drawn tho
 
How did this end up working out?

I've been looking around for a good dive knife. The only ones I"ve seen that really looked good to me were a couple Benchmade knives.

Benchmade N680
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Benchmade Axis
31H98KTprsL._SY300_.jpg


Benchmade Rescue/Dive
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Those are the only knives I've been considering.
I prefer a blunt tip so I'm leaning toward the N680. I'm not looking to get into some kind of stabbing battle with anything underwater and I don't want anything too aggressive because I'm pretty fearful of cutting myself underwater.

I've thought about putting together a design. I like the idea of a finger ring. Maybe something more like the CRKT Graham Ringed Razel Fixed Blade Knife 3" Chisel Point.
2012_xlarge_44.jpg
 
I too would like to know how these worked out.

Pathfinder, at the risk of embarrassing Ian, I cannot recommend his work highly enough. This is coming from a guy that favors Benchmade over any other production knife. Ians work is a leap above production products though.

Ian, since I'm sure you'll see this... After nearly daily use, the Santoku finally needs a touch up. I knew that my wife would like the xhp, but I didn't think it would take 4 months before I got to break out the edge pro! Fantastic heat treat on this one. ;)

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I did a batch of Ti dive knives a good while back. They were fairly thick, 3/16" IIRC. Ti is great because corrosion isn't a problem, and edge retention on a dive knife isn't an issue. Another great choice is dendritic cobalt. Stainless works well, too. While S35VN would work fine, 440C would be my choice for this type of knife.

I would use the handle from the dagger on the dive knife blade in your draw1ngs. Two side control and retention is a good thing on a dive knife. I agree that a line cutter is not needed, as whistles and bells are rarely used. A good sharp wave/serrated edge and a sharp straight edge along with a blunt wedge tip will work really well. The thing to consider is that the most likely use of a dive knife will be some type of prying. Design and HT for that use.
 
I think you need a narrower tip on the dive knife. I used to dive all the time in Guam. My dive knife had a blunt tip as well that I reground so it was narrow enough to still get into tight spots in the coral to get out shells. One of our divers on the ship knew I was into knives and such and had made a few so he introduced me to a EOD guy that were having custom made dive knives from Kit Carson done. They showed me the knife and I thought it was great. It was a tanto tip though. So I called up Kit and ordered one.

I ordered the large one with the blunt tip. I thought the one they had showed me was a large one. It wasn't. I didn't get it till I was back state side in Coronado, CA. The thing was huge. I had to wear it on one side with all my dive weights on the other side. I only made one dive with it, and then gave up diving as the waters off CA were no fun to dive in after being spoiled by Guam. I didn't like big murky things bumping into me in the sea-weed that I was never sure what it was. They were usually seal's but in mind every-time it was Jaws.
 
I actually finished the dagger and did a WIP, it morphed into a frame handle-ish design, with two piece changeable g10 handle.

http://www.bladeforums.com/forums/showthread.php/1121919-WIP-Tactical-Dagger-5-32-quot-S35VN-amp-G10

The dive knife is still on the table, but my friend wisely bought a cheapo to learn what works for him before we go on with the commission.

I too would like to know how these worked out.

Pathfinder, at the risk of embarrassing Ian, I cannot recommend his work highly enough. This is coming from a guy that favors Benchmade over any other production knife. Ians work is a leap above production products though.

Ian, since I'm sure you'll see this... After nearly daily use, the Santoku finally needs a touch up. I knew that my wife would like the xhp, but I didn't think it would take 4 months before I got to break out the edge pro! Fantastic heat treat on this one. ;)

Thanks for the feedback. :)

Jeff Mutz got me turned on to XHP, and it has been working well so far as long as I don't really try to push the limit on hardness.

I did a batch of Ti dive knives a good while back. They were fairly thick, 3/16" IIRC. Ti is great because corrosion isn't a problem, and edge retention on a dive knife isn't an issue. Another great choice is dendritic cobalt. Stainless works well, too. While S35VN would work fine, 440C would be my choice for this type of knife.

I would use the handle from the dagger on the dive knife blade in your draw1ngs. Two side control and retention is a good thing on a dive knife. I agree that a line cutter is not needed, as whistles and bells are rarely used. A good sharp wave/serrated edge and a sharp straight edge along with a blunt wedge tip will work really well. The thing to consider is that the most likely use of a dive knife will be some type of prying. Design and HT for that use.

Now that you mention it the symmetrical handle does make sense considering it will have two usable edges. The serrated edge wouldn't be as good to use unless you were cutting up with it.

I think you need a narrower tip on the dive knife. I used to dive all the time in Guam. My dive knife had a blunt tip as well that I reground so it was narrow enough to still get into tight spots in the coral to get out shells. One of our divers on the ship knew I was into knives and such and had made a few so he introduced me to a EOD guy that were having custom made dive knives from Kit Carson done. They showed me the knife and I thought it was great. It was a tanto tip though. So I called up Kit and ordered one.

I ordered the large one with the blunt tip. I thought the one they had showed me was a large one. It wasn't. I didn't get it till I was back state side in Coronado, CA. The thing was huge. I had to wear it on one side with all my dive weights on the other side. I only made one dive with it, and then gave up diving as the waters off CA were no fun to dive in after being spoiled by Guam. I didn't like big murky things bumping into me in the sea-weed that I was never sure what it was. They were usually seal's but in mind every-time it was Jaws.

One of the reasons my friend came to me was that nearly everyone I've spoken with that dives off California has mentioned the need for a good dive knife, as the seaweed can quickly turn into a prison.

Diving in murky water would creep me out big time. I'm not really the "monster under my bed" type, but still...
 
I think M390 is the best steel for the dive knife. It may be hard to get so you could try 20CV from Latrobe - it is chemically identical. I made a sailing knife with one side straight edge and one side serrated - worked great since serrated is the best edge for cutting hi tech line.
Tim
 
Sounds like you need a machete in the places you're diving. ;)

Look at the dive knives out there to at least get an idea what features you think would be good for your purposes
 
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