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LB-7 spring types

Posted: Wed Jun 10, 2015 1:57 am
by Stone
First off, let me say hello as this is my first post. I have been lurking for awhile and have decided that I'm hooked and can't stop collecting.

I bought a new LB-7 in 1983 and have carried on one my belt just about every day since then. It started showing signs of wear and I bought another in 1994. Lately I have been looking on ebay for another replacement as the one on display at the hardware store was not what I had been looking for. My first 2 Schrade knives were made in the USA and I wanted the same quality. These knives put up with daily use for over a decade. So after looking I have now found myself with a new knife about every week as I can't seem to stop buying them. I have this forum partly to blame. ::super_happy::

The springs are what I have researched the most on AAPK however that led me to learn much more than I had thought was even out there.

The spring on my 1983 LB 7 is the standard bar type. The newer one bought 10 years later has the twin flat springs as mentioned before in this forum which are sill in good shape. Neither of these knives have serial numbers as they were produced after the practice was stopped. However I do have two others that I just picked up that do have numbers stamped on them. One LB7 is numbered AY26323 and it had a chunk of flat bar stock wedged inside which I assume is part of the spring, which is broken. The other is a 4 pin with number K75254 stamped on it which does have the round bar spring.

I have found some music wire and am waiting on it to arrive in the mail. But my question is can I use the round in place of the square like bar spring? I will likely find out for myself when the spring wire shows up, but why not ask. ::groove::

Re: LB-7 spring types

Posted: Wed Jun 10, 2015 2:55 am
by orvet
I replace the springs with flat bars of spring steel.
I think Jantz Supply is where I got the last batch.
If you want round spring steel just go to Harbor Freight and buy a plastic squeeze clamp and use the spring out of it. Just cut it to the right length and bend to shape.


::welcome:: ::welcome::
Welcome to AAPK. Great first post! ::tu::

Re: LB-7 spring types

Posted: Wed Jun 10, 2015 4:16 am
by Stone
Thanks for the reply. 8)

I have a small stock of those clamps on hand. Cutting the spring and bending it out flat would be an option. But honestly, I need the clamp worce than the spring. I found two, three foot lengths of 0.090 music wire on ebay for like five bucks, shipped. Six feet of wire will go a very long way at 50 mm or so per knife. I don't ever plan on using it all up on busted/missing springs. But it's nice to have in stock for other projects too.

I would love some help on my one, 'square spring' LB7. It really is in great shape and I would love to use it as my daily carry. I don't have the the time right now to go and search and build the proper spring for it. I think I paid less than ten bucks for it so I have a bit to go before it's a lost cause.

Re: LB-7 spring types

Posted: Thu Jun 11, 2015 3:39 am
by Stone
I purchased another 4 pin LB-7 on feabay last night, and I got one that I bought last week in today's mail. It's becoming quite the addiction folks! :D

When the new one arrives I'll charge up the battery in the camera and work on posting up some pix. But one thing that I wanted to share tonight was with the knife which arrived today. The square bar, spring pin, was apparently around for at least a little while.

My two Schrade square spring LB-7's have serial numbers AY26023 and V78270
The newer one is in better shape and has a near perfect blade, but again it has the broken part. The older one I spent about an hour with lighter fluid and compressed air to get all of the gunk out of it before a light coat of 3 in one household oil to make things move freely once again. I also went and used a bit of polish by hand to take off the heavy tarnish and restore a little bit of shine to it. I resisted fireing up the machine buffer with the heavy grit metal compounds I used on auto parts and such. I feel the knives should retain most of their age and, "battle damage" if you will permit me to use that phrase. I don't feel sanding out the nicks and buffing them up would improve any value that they may have at all.

Re: LB-7 spring types

Posted: Thu Jun 11, 2015 1:38 pm
by orvet
I would have to do some research before I would make any sort of declarative statement as to when the square springs were used as opposed to the round springs, but I am inclined to think the square(ish) springs came first then the round ones.

The reason for the change? ::shrug::
I suspect it probably had to do with what was available from their suppliers at the time.
I have used flat bar spring steel and cut it to shape to make replacement springs and I have used round springs like those from the spring clamps. Both work and one seems to be as durable as the other.
IMO, either is preferable to the two flat spring system used in the later lock backs. This is especially true in the smaller knives from what I have seen. The smaller the knife, the more difficult it seems to be to get the proper heat treatment on the two flat springs. The 3OT pattern seemed to be particularly problematic.

Re: LB-7 spring types

Posted: Thu Jun 11, 2015 8:18 pm
by Stone
You may very well be onto something, Dale.

I may not have been to clear in my last few postings. I have two post 1983 LB-7's and three pre 1983, (two, 3 pin and one 4 pin) and with another what I believe is a 1979 4 pin model on it's way.

One of two pre 1983 three pin knives, (newer of the two) has an intact square spring in working order. The other only had a small chunk of broken square spring lodged within the blade nest. My older 4 pin, (the number of retaining pins seated within the wooden inserts) has no spring at all. I got it for free but the blade is so badly pitted it's hardly worth investing in for repairs.

Once my newest purchase arrives next week I will be able to see what type of spring the 4 pin had for myself assuming that it arrives with one at all. Ebay can be so reliable with descriptions from second hand dealers and pawn shops.

Re: LB-7 spring types

Posted: Fri Jun 19, 2015 6:24 am
by Stone
I do have a bunch of photos to upload as soon as I can get a chance. But my new arrival 4 pin did have the flat type spring.