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frame lock...should the lock bar....?

Discussion in 'General Knife Discussion' started by jbmonkey, Jun 21, 2012.

  1. jbmonkey

    jbmonkey Gold Member Gold Member

    Jun 9, 2011
    sit flush with the blade end....in other words make contact from the front to the back of the lockbar when looking at it from the side of the knife?

    i got one of those hk conspiracy knives.....while looking it over i noticed when opened, and looking at the side of it, the lock bar only touches the front of the blade side. the back side of the blade end(sorry don't know the right term for this part)doesn't touch. there is a gap looking at the side of the frame lock bar between the backside of the bar and the knife blade rear.....is this a bad thing for long term wear? i never bothered to check any other frame lock i own.....to see. will be doing that tonight after work. i always thought the entire lock bar surface should contact the blade end fully from front to back? did i get that wrong?

    thanks in advance for information.
  2. mkjellgren


    Nov 1, 2005
    Some frame locks are designed like this, strider comes to mind. If your lockup is solid I wouldn't worry too much about it. You'll just have to see how it wears. I'd be willing to bet that with a few hundred openings and closings the lockbar will settle in a but and that gap will disappear. As the tang and the lock bar become mated to eachother the lockup may improve. The flip side is that (like striders are known for) you may develop some vertical play, if this is the case, I'm sure benchmade will take care of you.
  3. matt123abc


    Apr 10, 2012
    Ya it should be fine. As long as there is no blade play it's ok.
  4. MikeC


    Sep 16, 2005
    I have a total different take on this on, its called a $hit vent by some and I can guarantee you either have side to side or horizontal blade play or will if you actually use the knife, if it is a safe queen not so much, but user, yes it is going to wobble. Yes, the entire surface of the lock bar face for as far as it engages should be in 100% flush contact with the tang. As you use the knife and the lock begins to wear whatever portion of the lock bar face is engaging the tang should again be in 100% flush contact. If not then what you have is a pivot point where only a small portion of the lock bar face contacts the tang and essentially becomes a pivot point for the tang and whamo you have side to side or horizontal blade play.
  5. Sonnydaze

    Sonnydaze Gold Member Gold Member

    Jul 6, 2009
    Mike makes sense to me.
  6. cutter17


    May 16, 2006
    I remember reading about this condition before and as it related to Strider folder's. You might be able to do a search on Strider folders lockup and find some info. Since I have my Lionsteel SR-1 (framelock) laying here next to me I just checked the lockup and the entire lock face is in contact with the blade tang and it seems really solid to me.
  7. Jfoley4


    Feb 5, 2012
    There is no right or wrong way. As long as there is no blade play.
    This is what you mean correct?
  8. cutter17


    May 16, 2006
    He is talking about the face of the lockbar making contact with the blade tang along it's entire length. That length could be anywhere from 1/8" and up/down, depending on where the lock is cut in the handle.
  9. Jfoley4


    Feb 5, 2012
    Gotcha. Thanks for the clarification. I figured it could use a picture just in case.
  10. jbmonkey

    jbmonkey Gold Member Gold Member

    Jun 9, 2011
    No Sir. Turn the knife to the side and look at the lock bar as it sits on the blade. I checked my other frame locks and they are flush or no gaps. Not this one though. Seems it will develop play sooner or later. Its a strange deal to my untrained eye.

    Thanks all for the feedback. Appreciated.
  11. Ernie1980

    Ernie1980 Gold Member Gold Member

    Apr 19, 2012
    Can you post a pic of the lockup?
  12. cutter17


    May 16, 2006

    THIS is what I was trying to say.:thumbup::) It is the bottom to top of the lockbar, and not the thickness of the lockbar, that he is talking about. The picture you posted is about where I like the locbar to be on my knives.

    Edited to add;

    Though pretty crappy, this pic shows the how the lockbar covers the tang of the blade in such a way that there is not open space between.
    Last edited: Jul 7, 2012
  13. Ramiel


    Aug 5, 2011
    I think there should be a gap, a frame lock is the same as a liner lock in its function, and Mr. Emerson is probably correct (see the following link where he explains proper lock engagement)
    Last edited: Jul 7, 2012
  14. MikeC


    Sep 16, 2005
    Regardless of what Mr. Emerson or anyone else says, I can tell you from experience by actually using frame locks that if there is a gap, it is going to develop blade play if there is not a gap and the lock bar nest or rest flush against the tang, then even wear, solid lock up and no play. All my framelocks with gaps have lock rock, all my ones that are flush solid, no blade play either vertical or horizontal.
  15. marthinus

    marthinus KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Dec 10, 2006
    Here are some comments from a very well and respected maker on the forums that has tested numerous locks. I will not post his name as this was a private conversation and lets keep it that way.

    "I've done some steel inserts in mine. The wear rates are not far off from titanium to steel. Both wear very well. Heat anodizing helps to form a deeper near ceramic hardness on the titanium since heating it by a torch anodizes the ti from the inside out as opposed to using a DC current which is from the outside in or the outside layer only. That ceramic hard oxide layer wears pretty well against even the hardest blades. If it didn't people would have stopped using ti a long time ago.

    The real factor as I see it is impact strength not wear resistance. In my own testings for Kershaw and other companies that sent me product to beat the snot out of on their behalf I found that the steel frame knives held up better to sudden shock impacts like spine and overstrike whacking as opposed to the softer ti which could indent easier and deeper scarring the surfaces more. So to me this is the key factor behind it but there is a draw back since steel is less forgiving than titanium. Ti tends to gall or stick to itself and dissimilar metals and this sticking effect has been seen forever by makers as a real benefit.

    Not to sound bad but you can be off some on contact angle and get by with it by using ti since it can make up for your shortfallings here whereas steel would just slide right off the contact. Steel will demand the contacts be spot on and if they are not well, you'll see locks sliding off the contact toward release easier than ti when the contact angle is not right.

    I've used inserts of steel in a couple folders I did a while back. To me having to do them the way I did they were more trouble than they were worth. Most of my folders give me very little trouble as it is. However, I am low key and not selling what is being marketed as a 'hard use' knife either. We'll see how long this lasts but it could be the beginnings of a trend in the hard use category if people start testing them and find they hold up better. It will depend on the steel used. I really fail to see much benefit if the steel they are using is just 410 stainless at 45 Rockwell. Ti is 39 Rockwell or so and although softer by quite a bit technically it wears at such a slow rate that in normal use most folks are not going to notice any diff or benefit to this insert at all. Its just the guys beating on them that will pick up on it probably.

    Now that goes to another issue. What happens when the insert dislodges or falls out? The screws will have to be very secure for some of these guys beating on them and if they think the knife is supposed to take it they will do that. Again time will tell. My thoughts are that overall there are some benefits from the stand point of repairs.

    Its much easier to replace an insert to refresh a lock that has worked its way all the way across the contact. This beats the hell out of making a whole new lock or peening the contact like Emerson, Kershaw and many other companies do to repair theirs. Don't get me wrong thats an old cutler trick as old as the liner lock itself and it works. Heck many makers do it as a part of the process along with heat treating because they believe peening compresses the molecules making it denser so it wears better.

    The point is that is not as precise as people like to be whereas a new insert would be, well, new and just like it was before theoretically. It may even be something the user can do themselves in the field or at home. We'll just have to see how this develops. "

    :peening the contact is a technique used by cutlers to 'refresh' the actual physical contact area on the lock where it connects to and wears against the blade in use. Sine the lock is technically supposed to connect and support the blade at the bottom of the lock at the point far enough away from the mid line of the pivot barrel or pin to prevent 'blade roll', (bottom being the area many refer to as the top since its up by the thumb grooves where one depresses the lock to release and free up the blade to close it. Think bottom of the blade when opened and that is technically the bottom of the knife and the where the edge runs with the spine of the blade when opened being at the bottom running along the full length of the folder)

    So again since the lock connects at the bottom you have a triad or three points to support the blade when opened. The stop, the pivot in the middle and the lock. If the blade connected to the lock more in the middle or at the top of the lock down where the detent is on most then you would experience blade roll. This is when you have vertical type play but what happens is the blade actually rolls on the lock because the lock connects in the wrong place.

    The lock should also be flat not angled at a pitch like the contact is on the blade. Some makers make them and the blade is not quite right so they adjust the lock to fit the blade instead of the blade to fit the lock. This is incorrect and it can cause a 'stepped' or angled pitch to be formed on the lock and that in conjunction with a pitch on the blade is a sure fire way to lead to lock defeats.

    When a lock wears and works its way across the tang to the opposite side liner or when it develops blade play many times the maker or the manufacturer will correct this not by bumping up the size of the stop pin but by peening the contact area. This again if you picture it is the area showing signs of wear marks on the lock itself and it should be somewhere on the bottom third of the lock far enough from the mid line of the pivot to make a rock solid contact for no play in the blade. Peening means a ball peen hammer and a 3/32 flat end punch placed precisely at a the area just to the left of the contact on a right handed knife. You swing the hammer hitting the punch so it physically 'squishes' out the contact more toward the blade. When done this creates a little 'bubble' sticking out just a few thousandths of an inch and it refreshes the contact as well as compresses the material. This can be done on steel, ti or brass locks and requires different touches or pressures to do it right. Its been done on compression locks and lock backs also to peen the usually softer area of the rocker arm just a micron or two to adjust the lock for fit before they ship it out the door.

    Anodized ti is usually surface only. Heating with a torch usually brings the ti lock contact up to a straw color or at the least a cherry red orange color. Letting it cool on its own and repeating this three times builds up quite a bit of anodizing that at times can be resistant to even bead blasting it off and it can harden the metal to the point that it is much more wear resistant in that spot that was heated. Most are done and then blasted afterwards cleaning off the surface that is seen. Others simply don't treat it knowing that titanium is technically a 'self healing' metal that creates an oxide layer on its own as soon as fresh ti is exposed to oxygen. This is true by the way and why ti is resistant to all kinds of corrosion. Its that oxide layer that forms a barrier between the ti and the atmosphere sealing it off that makes it so resistant to it. Heat and electric current simply stack on layers of this seal and the light refracting off those multi layers is why we see colors. You actually would have to read some of the tech manuals on that to get the full jist. I'll stick with a nut shell description.

    Correction. Steel would probably have been dinged also just not as bad and this depends as you said earlier on type of steel, how hard it was set at and so on. Steel as I said requires that things be just so. I repair a lot of knives and most are liner type locks of the thinner type. These wear and indent and even in steel. They also of steel tend to be easier to find fault in contact angles. For example you see a few knives with steep pitch angle contacts 12 degrees or more and to try this with steel will surely cause the locks to defeat with a sharp tap to the spine. Most steel locks need a pitch of 7 to 8 degrees max to work. 10 or above is really pushing it and even Spyderco walks that fine line at times as I see plenty of Military folders with locks that slide toward release back to the flatter area on the blade contact. This with simple spine pressure from my hands so there is no telling how that would go for the user if it was a sharp blow to the spine. "


    Peening the contact is a technique used by cutlers to 'refresh' the actual physical contact area on the lock where it connects to and wears against the blade in use. Sine the lock is technically supposed to connect and support the blade at the bottom of the lock at the point far enough away from the mid line of the pivot barrel or pin to prevent 'blade roll', (bottom being the area many refer to as the top since its up by the thumb grooves where one depresses the lock to release and free up the blade to close it. Think bottom of the blade when opened and that is technically the bottom of the knife and the where the edge runs with the spine of the blade when opened being at the (insert TOP not bottom as I said) running along the full length of the folder) Even I get confused. Lay people often mean top when they mean bottom and bottom when they mean top because these two points are confused.

    The point is the lock should connect at the bottom third of the lock and no where near the pivot mid line or top. "

    And here are some other comments from me and my opinion.

    For those like me that like the theory

    A recent few posts I did regarding frame locks, but many of the same principles apply to liner locks geometry.

    "There are a few things I want to cover, based on my talking with custom makers and reading Bob Terzuola's book: The Tactical Folding Knife (hereafter BT), where he explains in detail the aspects of a good liner lock and the same principles are applied to framelocks.

    Three points of contact:
    1. Stop pin
    2. Pivot pin
    3. Interface between blade and spring (ie, lockface/lock engagement area hereafter referred to LF) Spring is also the liner lock, framelock.

    This forms a triangle.

    Now, the LF is the area lets focus on first.

    BT. refers to the angle of the lock face to be between 7.5 and 8.5 degrees. Les then 5 degrees and the spring will jam. More then 10 degrees and the spring will start slipping off the LF.

    Now the start of a radius lock face, the maximum therefore cannot exceed 10 degrees or else the lock will start slipping when the lock wears to that point. As mentioned as lock roll in the video when referring to the Strider.


    Do not thing the angle plays the only role in the lock slipping. The finished LF can have a rough spot, not be polished enough, the spring's interface between the LF can also play a role.

    Let us examine this from the Emerson website.


    If the LF connected to the spring more in the middle or at the top of the spring where the detent is on most (point nr 3 closer to the pivot pin nr 2) then you would experience blade roll. This is when you have vertical type play but what happens is the blade actually rolls on the spring because the spring connects in the wrong place with the LF.

    The picture shows the extremes of the different designs, you can have a lock that engages more then the bottom 0.90-.125" of the spring. Chris Reeve has proven this, but, you can also have a knife that engages only on that bottom 0.90" (point of contact in the picture)

    Not every lock is the same. The basic ingredients are the same, but the final application is what the maker chooses. This can be seen even with Spyderco difference between the Military and the Gayle Bradly.

    Now that is just the geometry of the lock.
  16. marthinus

    marthinus KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Dec 10, 2006
    The spring itself if it is Titanium can be heat treated or carbonized. Strider and Hinderer do the latter. This helps tremendously with wear on titanium and if done right will last you a life time. CRK and a few custom makers that I have do Heat Treating of the lock. Wear is about nun and equal to (if) steel was used.

    HOWEVER. Titanium is NOT PERFECT and it can have flaws in it when received from the supplier. EVEN aerospace titanium (grade 5 titanium). These flaws only become apparent when it is used and is sometimes not even noticeable until it begins to form a problem. This is where a good warranty comes into play.

    Steel used as a liner is not always the answer as well. Different steel interfaces can result in slipping. Steel on steel requires a lot of research to find what can be used and heat treated as a spring and still provide excellent wear resistance and safety.

    Finally, lockup percentage is a strange thing and depends on the final user. I prefer later lockup as it usually means less chance of slipping off the LF.

    I hope this helped you in some way."

    At the end, if you either use Ti or Steel, the LF geometry is key.

    I have Ti lock custom that I have flicked vigorously, the maker asked me to test the lock face.

    BT also writes in his book there is no significance between steel and Ti if done right. A Sebenza will wear for a while and then stop. Most quality locks do this. Chris Reeve also wants a later lockup as he feels it provides a safer lock and less chance of slipping. I tend to agree. Besides. If any quality product wears out so fast, they should cover it under warrenty.

    I have seen a 18 year old Sebenza. No issues. I have a Military with the steel insert. No issues. Both locks apply different end results, but the basics are the same resulting in great locks that can last you a live time.

    BT also feels that the strength to weight ratio of Titanium is excellent compared to steel.

    Some imagery from custom maker Gareth Bull
    Comments from well known custom maker Des Horn
    I hope this can be useful and educational to some. I know I went a bit of topic... from steel vs Ti, but you have to look at it as a whole in my opinion :)
  17. Dane.Chichester


    Mar 9, 2012
    Here are my two EDCs...both have full contact with the blade tang and neither have a bit of wobble or play.

    LionSteel.JPG Sebenza.JPG
  18. cutter17


    May 16, 2006
    Thanks for posting the information marthinus, as it was really interesting to read and to learn more about the liner/frame lock knives and how the lockup should be done.:thumbup::thumbup::)

    Now I do wonder about the lock that engages completely from top to bottom as my LionSteel SR-1 does. The blade tang has somewhere between 7 to 10 degree pitch, while the lockface of the steel insert is flat. Lockup is certaintly secure and it will not back off the blade tang under pressure, at least under the pressure I tested it at which is not a whack, but rather 5-6 rapid taps on the blade spine.

    Again though thanks for the posting the great info!!
  19. marthinus

    marthinus KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Dec 10, 2006
    One of the best ways I have seen to test a liner/framelock for any issues is to do the following (this was posted back in 2007):

  20. jbmonkey

    jbmonkey Gold Member Gold Member

    Jun 9, 2011
    yeah, sorry about the wait on the pictures....here you go.....

    cellphone pics, sorry about low quality the dark area is the back of the blade not touching the lock bar. so it only touches in the very, very front. hard to capture in a picture. also the pictures don't really capture it all that well...in your hand in the metal it's much easier to see what i am asking about. so y'all are gonna have to trust me somewhat.....thanks.

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