Folder Pivot question

Patrice Lemée

Patrice Lemée

Joined
Aug 13, 2002
Messages
5,703
I need a bit of help with this. I feel kind of silly for asking really but for the life of me I can't figure it out. :o

You see I have these pivots with 2-56 screws.



I want to hide the pivots under the bolsters but don't know how. The head of the 2-56 screws are smaller than the pivot OD so how are they suppose to tighten against anything? If I went through the bolster I can see drilling a clearance hole for the screw and having the head lock against the bolster. But how about underneath? Do you use a washer to lock against the liners?

I've looked through all my saved WIPs but can't find any showing what I am talking about. Or maybe it's there but I am just too dense. Which is more than a possibility. :o

I hope this makes sense to someone.

Any help would be greatly appreciated.

Thanks
 
They are of the incorrect size, of course. You want 3/16" pivots with 4 X 40 screws, or 1/8" pivots with the 2 x 56 screws. The ones you have are made so that the shaft can be taken down for a 1/8" hole that is oversize. Frank
 
Last edited:
Not sure, but would this work...?

Grind the pivot barrel down to the final thickness needed between the two liners (may need a pivot lapping block?). Drill a clearance hole in the liners for the screws, then the head will sit against the liners. I guess if you wanted some more surface area, a little washer under the head? Then just drill enough out of the interior of the bolster for the head of the screw. No idea if that's a good or reasonable bet, just what came to mind.

Jeremy
 
Patrice, Frank is right about the 3/16" pivot.
I have used the 1/8" pivot on smaller knives. Here is what you can, grind the pivot flush under the bolster . The drill the bolster with a #44 drill ( that will let the screw pass thru the bolster the you could counter bore the bolster so that that head of the screw is not sticking up so high.

http://i1217.photobucket.com/albums/dd388/Bladeworks2011/BingaLor/73_zps20ad65de.jpg

Hope this will help

Bing
 
I'm going to jump in here and ask questions because I am getting close to starting on my first folder. Could he just counter-bore the liner for the screw head and clearance the back of the bolster for any part of the head that won't be sunk into the liner? This seems really simple, am I missing something here?

Bob
 
Thanks a lot guys. From your comments, I think I simply got the wrong screws. This is what I ordered:

http://usaknifemaker.com/folding-kn...l-3-16-x-1-2-l-for-folders-w-2-56-thread.html

From the pics, it looks like the screw head were suppose to be larger than the OD. Probably the 0.250 in the description. I'll email Tracy to get confirmation.

Thanks for the other suggestions also. I might go that way depending on how long it takes me to get proper sized screws.

I am liking this folder thing, a little like take downs I like so much...just more complicated. ;)
 
From that page, I would expect that 2-56 x1/4 refers to the thread being 2-56 and the screw length being 1/4inch. That is the normal way for bolts and screws to be described. I spend a fair bit of time looking at specs for screws and bolts for work and head diameter doesn't enter into the description. The picture looks like 2-56 thread and 1/8th pivot. The same photo has been used for two sizes. Sounds like you really wanted something more like this:
http://usaknifemaker.com/pivot-sexbolt-3-16-w-a-430-shank-includes-6-32-button-head-screw.html

Best of luck :)
 
Yup, I got those too (from Jantz, I think) once.
My solution was that since I wanted the pivot barrel to go through the liners so that it would be true and solid, I pre drilled the holes through the liners and the bolster with a drill sized to give clearance for the screw, then drilled/reamed just the liners to pivot size. IIRC, that was a bolster that was screwed onto the liners rather than soldered....then countersunk the screw heads into the bolster.
I think I did one or two that way, and then said to myself, "Good Grief, Charlie Brown" and ordered a bag of extra screws of the correct size to go with my pivots.
 
Almost all 2-56 screws are cold formed. The head and drive are formed in one operation in a die with high pressure. The tolerances for 2-56 cold formed pan and button screw head is .160" +-.004". The advantage of cold forming is cost.

There are some 2-56 screws with larger heads. Almost all these are made with a screw machine. A screw machine is a very expensive lathe that maintains very tight tolerances. The screw machine that makes our machined screws costs $500,000 and maintains -0.0" +0.0002". The disadvantage of machined screws is cost.

If you want to use the pivots you bought and have the pivot screw to be hidden under a bolster, buy flat head 2-56 screws. Countersink the liner so the pivot screw is flush. Cut the pivot to the correct length and sandwich between the liners.

Chuck
 
My apologies Patrice, I miss understood you question. I thought you were trying to do an exposed pivot n a counter bore as I do in my process, with the oversized head.

Chuck explained it well.

Bing
 
Chuck, you will have an order coming in a few days for some pivots of all kind. Do you also have some of those large head 2-56 screws?

Thanks again for all the help and suggestions guys. And Bing, no need to apologize my friend, the exposed pivot is a possible option.
 
Hello Patrice. I like to use 3/16 pivots with 6-32 screws. They have around .250 heads so lots of meat to hold onto. You can still countersink the back side of your bolsters.
 
By the way, best to buy the largest size of pivot that will fit the folder you are making.
In other words a 3/8" wide blade will take a 1/8" but not a 3/16" wide pivot. A 3/16" pivot works well for a 3/4" blade and a 1/4" one might even be better. Blades much wider than 1" may require custom made pivots. The pivot with the side washers provide lateral alignment as well as support from the pivot for the blade when in use. I recommend when buying pivots to get a few extra screws, in case you destroy one in the fitting. Frank
 
Thanks Frank, I will try do to that and order some .250 pivots for larger blades as well as on bunch more screws.
 
I have been buying my pivots at knifekits and USAknifemaker. Some extra torx screws will come in handy as well. Dave.
 
The pivots at AKS, Jantz and USA Knifemaker are all very accurately made. I personally like the barrel type to work with. How do you accurately size down the ones that have a head on one end? Frank
 
I actually only use the barrel type as well. To shorten them I have a piece of dymondwood with a 3/16 hole in it. I just put my pivot in the hole and place on my 6x48 belt sander and apply a little pressure to the pivot. Keep measuring until I reach my desired length.
 
Now there is aman that will always get the job done !! I'm sure that will be very useful to many. Frank
 
You must log in or register to reply here.
Back
Top