More first folder questions

A

aslink

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Nov 29, 2014
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I’ve ground and built my own fixed blade knives for sometime now. I’ve sold pretty much everything I’ve built. So all in all I would say things are going well. For fixed blades I had my Dad to mentor me. However liner locks were not his thing he's was a frame lock capture pin kind of guy. So I find myself in uncharted territory.

I’ve been interested in building my own liner lock for sometime. Mostly because that is the type of knife I like and carry. So I wanted to start there. I am reading Bob Terzuola's book on Tactical folding knives but at the same time I wanted to address my fellow builders for their input.

I have several questions on materials and how to work with these materials. I’ve been searching and reading forum posts for some time as well and some of my questions have been answered but some have not. So instead of posting all my questions at once I’ll post one and when that one has pretty much been answered I’ll post the next. Following to many questions and answers makes my head swim so I’m going to try and manage this a bit on my end if that’s okay.

My first questions will be dealing mostly with titanium, so here goes.

I have a beautiful Stan Fujisaka knife I’m referencing as my starting point. He uses a .050 thick titanium liner. For my knife I’m thinking it will be for more hard use should I look to a bit thicker material like .06 or even a .08 or is that unneeded overbuilding?

My concern is the contact point of the liner lock and the blade steel.

I’ve never carried at liner lock with titanium so I’m unsure as to the wear of these metals and the abuse titanium stands up to. Even though I have this Fujisaka it’s more of a reference and safe queen piece. I’m not in the habit of carrying $300 pocket knives for edc. So I’ll be building and testing one of my own.
 
I will try to help a bit, but first off if you "search" here you well get lots of great go ahead stuff for liner locks.
Since there is nothing more than the actual edge of the titanium leaf that makes contact with the 8 degree angle cut in the blade the thickness of the titanium is only going to come into play if it's going to be a folder that sees lots of pressure on the edge of the blade such as if the blade was dull or the user decided to do some cutting more in line with where an axe or saw could be more effectively used.
I use .050 or thereabouts as availability allows for my folding hunting knives with blades of about 3 1/2" - 4" . Should you wish you can get smaller pieces of titanium in many sizes and thicknesses from Alpha Knife Supply.
Design however will sometimes dictate that a thicker liner will be used as is commonly seen in frame locks where the one side does not have a scale or bolster.
Frank
 
Frank, thank you for your time it was helpful.

Pretty much all my research so far leads me to think ti is a real pain to work with. Seeing how I've never worked with ti should I work with this material to build my first liner lock or should I use stainless? My concern is in regards to tapping for screws, I'm looking to use 1-72 flat and button heads. More builders say they've broken more taps working with ti. Is stainless going to be as challenging?

Also the stainless I'm looking at is 17-4 and 410 on the Jantz website. Is one better than the other?

I do not have a tapmatic or the budget to purchase on either. I'm thinking as a interim fix to purchase a tapping fixture from Hawkings Knife Supply. Has anyone used one of these and how well does it work?

I have a couple things to adjust in my knife design once I get that corrected with all the new info I've learned I'll post a pict to get some feed back.

I really appreciate all the help not just my posting but all the posts I've read from this forum.

Thanks guys,

Ken
 
First off you will need to spend several dollars just for tooling to be able to make your own liner lock. Are you ready for that.
For taping titanium I go one drill size larger than what is given in the charts. I use a 55 for a 0 X 80 screw. You can buy from USA knifemaker Supply for under $20 a tap holder that will fit in your drill press for alignment but you manually turn. I have done several thousand holes with a similar one and only broken a couple of tapes that were well past their cutting prime. Could you heat treat the stainless for spring use? Using the titanium is just another adventure into the knife making process.
Frank
 
I have one of the tap holdings fixtures from Hawkins and it works well. I haven't broken any taps since I started using it.

I did mount the fixture to a small block of steel to give it a little more weight while working with it. I think the block is 4" x 6" x 3/4". I also use a small syringe for applying the tapping fluid and compressed air to blow out the chips as I tap
 
Frank, I do have some cash at the moment it invest in this. I just wanted to make sure I was investing wisely. 40 bucks to me is worth avoiding the hassle of not slipping the belt off the drill press to tap by hand so thank you "plas62".

Great tip in mounting the fixture on something for weight. I have a versatile jig set up that I use for working my knives during various steps I'll add this as another one of those. I'll take some picts and share those too.

As far as stainless goes I was going to order some 410. From your comment I take it I'll have to heat treat it? I'm hoping this is a yes or no question. Does 410 heat treat the same as ATS-34 and 440c? Reason being I'm familiar with air quenching but not the other methods, I pick and choose my learning curves and try not to stack to many at once.

And do I create the spring before or after the heat treat?

Thanks again for the help, I really appreciate it.

Ken
 
You wouldn't be heat treating the liner except for the fact you need a leaf spring there. I don't know if 410 can be heat treated or not. I'm a little confused . You seem to be very organized and methodical from your posts here. The stainless thing just isn't what works well for liner lock LINERS. Look in the folder for sale and folder build areas and see how many liner locks you can find made with a stainless rather than titanium. Any?
Frank
 
I have a Benchmade Dejavoo as an EDC. One side is very polished and the other not as much. Upon closer look and a quick search I found out that one side is Ti and other is 420 SS. I always assumed it was SS. Yet again see what happens when one assumes.

Thanks for pointing me in the right direction.

Okay now that I'm going with .050 Ti. What is the best way to cut this material. In Bob's book he references a slitting blade for the longer cut. Before I saw that I have a 15" drill press with a decent X Y vise. I was thinking a small end mill bit, is that okay? After that I have a jewelers saw.

Next I was watch a Video on Ti pocket clips at USA Knifemaker and he made reference to heat treating the Ti clips. Is this something I'll have to research?
 
The best thing for you is to get a plain ordinary hack saw with some blades with fine teeth. No, the drill press idea and end mill is totally a lost cause. The titanium pocket clip is the last thing you may make, but the heat can be used to colour it.
Have you made a hard working pattern? If not you should get that sorted out. If you don't make that you will never accomplish making even the basic parts of the folder. My advice here is to keep the blade length about 3" - 3 1/2" long.
Frank
 
Thanks Frank you've been very helpful through this whole process. One last thing when you say "hard working pattern" do you mean template or similar or is this yet another thing it seems I'm unfamiliar with.
 
Yes, a template made from a very stiff cardboard that you can cut out the three needed pieces, with pivot hole of the size you will use, attatch or glue on the back bar and place the template blade on the pivot to see if it will open and close and fit inside.
Frank
 
Well I finally had the time to update my drawing of the knife in question. Let me if I need to change anything.

DjOgGok.jpg
 
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I believe it will work, but I see where a better folder action can be made if you can move the flipper more forward when in the closed position. Yes that could mean a huge design change. So perhaps just stay where you are for the first.
Frank
 
Thanks for the input. This is my first attempt at a folder, obviously. To add to my difficulties I have a friend/neighbor that owns a custom automotive shop that wants a custom folder. He wanted 10 of them for the Christmas season. Would be great order but in October it was a little late to be building a new shop, designing a new knife and assembling 10 folders. One of his must haves is a flipper which has added a complication for my first design. He also wants it to be an assisted opening, I will tackle that at a later date.

So my hope is to develop my folding skinner and use that same action in his custom folder as well as in a more tactical folder which I would carry as my EDC.

I'm going to print this out and create wood pattern to handle and see how I like it. I'll post my findings.
 
Your process of preparation appears to be correct in that it is very methodical. This going ahead with the wood pattern is an great way to go on especially your first pattern. I believe you will find it to be oversized in width. You can slim it down some and still end up with a good design for a skinner.
Frank
 
410 Stainless steel is not a spring steel. Spring grades are 302/304, 316, 17-4, 17-7, Alloy 20, A286, and probably several more.

Although you are apparently going with titanium for the liner lock, a stainless would work well too . . . in which I would personally use a spring grade. These would require working while annealed and then heat treated and tempered afterwards.

Good luck with your project. I want to move into folders too, but am waiting until I can acquire a mill and a surface grinder. At this pace it will be a few more years.

Mike L.
 
Thanks for the great info.

Hey I've been trying to figure out how better to cut the long line in my spring. My titanium spring will be in an "L" shape. I was at Home Depot and saw Demel has a new diamond cutting blade. Any thoughts?
 
Sure.
Get yourself a package of those thin cut off wheels practice a bit on some scrap and you should do fine. I made myself a cross sliding set up after I did many by hand. This is NOT a job to do early in the making. You must wait until along quite a piece or you will have to start over.
To start, cut two rectangles that your liner pattern will fit in of titanium about .050 thick. Punch mark the pivot position on each and drill the holes with the correct size reamer for the pivot diameter you will be using. Now place your hard thin pattern on ONE piece of titanium and place the pivot or the smooth side of the drill bit through to align the pattern. Now scribe around the pattern. Cut this out and grind the pattern to the scribed line with a 60 or 80 grit belt. Now leave this and get your blade at least contour ground with the pivot hole also drilled and reamed. Place the blade on the liner and see if it fits inside the outline of the liner and can pivot out and in without interference.I have found there is often a need to adjust the blade or liner narrower or shorter. This should be done before going any further.
Lots more to come. Frank
I will try to answer any questions but know now I don't send pictures to the forum.
 
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