Folder Spring Galling

A

Andybrock

Joined
Feb 5, 2017
Messages
60
I keep getting galling on the end of my spring where the tang rotates around it, I’ve deburred, radiused the corners of the tang and polished it. I’ve also polished the flat of the spring where the tang sits.
I use oil when operating the knife.
The blade is 60hrc and the spring 45hrc, should I be going a little harder with the spring? Any advice would be appreciated.
Thanks
 
More than likely you still have small burs on the tang. After putting the radius on the corners put a piece of 400 grit paper on a flat piece of steel and hand sand around the radius. Should solve the problem.
Also never operate the knife with a bur, if you start to open or close and you feel it start to cut, stop and fix the problem.
 
SBuzek said:
More than likely you still have small burs on the tang. After putting the radius on the corners put a piece of 400 grit paper on a flat piece of steel and hand sand around the radius. Should solve the problem.
Also never operate the knife with a bur, if you start to open or close and you feel it start to cut, stop and fix the problem.
Click to expand...

Ok, many thanks.
 
I'm just learning so I'm no expert. I have the Luke Swenson slip joint build video and he specifically talks about finishing your tang to a higher polish than the spring to prevent galling. I think he does 600 for the tang and 180 for the spring. He also mentions that your tang heel and the bottom of your spring, they should be ground length ways so when those surfaces interact with each other the scratches from both are running in the same direction if that makes sense.
 
Signalprick said:
I'm just learning so I'm no expert. I have the Luke Swenson slip joint build video and he specifically talks about finishing your tang to a higher polish than the spring to prevent galling. I think he does 600 for the tang and 180 for the spring. He also mentions that your tang heel and the bottom of your spring, they should be ground length ways so when those surfaces interact with each other the scratches from both are running in the same direction if that makes sense.
Click to expand...

That could be my problem as I’ve buffed and polished both surfaces. I’ll take the contact part of the spring down to 180, see if it makes a difference. Thanks.
 
I've struggled with galling here and there. Here were the culprits most times:
  1. Burrs. They can be the cause OF the galling or be created super quick as a result of galling. Sometimes hard to chicken and egg things. A tiny chunk of grit, shaving of metal or such can get it going easy.
  2. Uneven flats. The more surface that mates square, the less galling I've found. If your tang has a "high point" where it rides almost solely along the spring, the pressure isnt spread out and I've found it can dig in. I now cut the flat where the tang rides on the spring and any other flats I can that touch each other on my mill to make sure it is super square. Galling I always saw a "line" showing only one part of the spring was taking all that pressure.
  3. Spring pressure to tang radius. If you want "snap" it seems you either need higher spring pressure with more radiused corners or sharper corners with less spring pressure. High pressure and sharp corners is when I had galling.
Last few I did where I focused on a nice tight radius on corners, making sure those radius were square to the spring and the spring mating surface was square to the tang plus lightening up and paying attention to burrs seems to have removed this issue. Thinking back, my early slipjoints had far too "square" corners for the strong snap I was giving them and I think that exacerbated any other factors.

Other things I've tried that seemed to help: Graphite on mating surfaces on initial assembly. Galling seems to either happen right away or not at all. I'll agree that polishing less seems to help and high polish on those surface never really felt much smoother.

I feel your pain...its super annoying to get to assembly point, gall a spring then have to both take the spring back down and the tang cleaned up to even 'try" again.
 
Stainless must not have the same finish on both surfaces. I do the spring where the tang rides at 120 grit and the tang at 400 and polished.

Everybody should buy Luke Swensons video.
This month Bill Rupple will have a video as well and will be a must have.
 
David Schott said:
I've struggled with galling here and there. Here were the culprits most times:
  1. Burrs. They can be the cause OF the galling or be created super quick as a result of galling. Sometimes hard to chicken and egg things. A tiny chunk of grit, shaving of metal or such can get it going easy.
  2. Uneven flats. The more surface that mates square, the less galling I've found. If your tang has a "high point" where it rides almost solely along the spring, the pressure isnt spread out and I've found it can dig in. I now cut the flat where the tang rides on the spring and any other flats I can that touch each other on my mill to make sure it is super square. Galling I always saw a "line" showing only one part of the spring was taking all that pressure.
  3. Spring pressure to tang radius. If you want "snap" it seems you either need higher spring pressure with more radiused corners or sharper corners with less spring pressure. High pressure and sharp corners is when I had galling.
Last few I did where I focused on a nice tight radius on corners, making sure those radius were square to the spring and the spring mating surface was square to the tang plus lightening up and paying attention to burrs seems to have removed this issue. Thinking back, my early slipjoints had far too "square" corners for the strong snap I was giving them and I think that exacerbated any other factors.

Other things I've tried that seemed to help: Graphite on mating surfaces on initial assembly. Galling seems to either happen right away or not at all. I'll agree that polishing less seems to help and high polish on those surface never really felt much smoother.

I feel your pain...its super annoying to get to assembly point, gall a spring then have to both take the spring back down and the tang cleaned up to even 'try" again.
Click to expand...

Thank you very much David, I’ll try your advice.
 
AVigil said:
Stainless must not have the same finish on both surfaces. I do the spring where the tang rides at 120 grit and the tang at 400 and polished.

Everybody should buy Luke Swensons video.
This month Bill Rupple will have a video as well and will be a must have.
Click to expand...

Thanks, I’ve just downloaded Lukes video, it looks a wealth of information!
 
Drew Riley said:
Thanks for the heads up! I just checked Chris Crawford’s site and it looks like Craig Brewer has one coming out too. Looks like Christmas is coming a little early this year. Can’t wait!
Click to expand...

Just got the Bill Rupple video on multi blades.
I will probably watch it a dozen times and burn it into my brain.
 
AVigil said:
Stainless must not have the same finish on both surfaces. I do the spring where the tang rides at 120 grit and the tang at 400 and polished.

Everybody should buy Luke Swensons video.
This month Bill Rupple will have a video as well and will be a must have.
Click to expand...
In the Luke Swenson video, he takes the spring to sevaral micron level belts thenbuffs the springout and tang I think to 400grit 1:17:40 2nd dvd
 
Last edited:
ashwinearl said:
In the Luke Swenson video, he takes the spring to sevaral micron level belts thenbuffs the springout and tang I think to 400grit 1:17:40 2nd dvd
Click to expand...
You need to watch that again carefully
 
AVigil said:
You need to watch that again carefully
Click to expand...
I only have the basic video not the second embellishment video. Do you know where he talks about roughing up the part of the spring where the tang rides?

In the basic video, right after he polishes the inside of the spring to mirror, he says that the next steps are going to be in a separate video showing embelishments. The video then restarts with the knife pinned with assembly pins and then he starts cleaning up the outside, then goes onto final assembly and peening.

I talked with a guy that trained with Luke an he confirmed what you said about relatively rough grit (120-200g) on the part of the spring where the tang rides.
 
ashwinearl said:
I only have the basic video not the second embellishment video. Do you know where he talks about roughing up the part of the spring where the tang rides?

In the basic video, right after he polishes the inside of the spring to mirror, he says that the next steps are going to be in a separate video showing embelishments. The video then restarts with the knife pinned with assembly pins and then he starts cleaning up the outside, then goes onto final assembly and peening.

I talked with a guy that trained with Luke an he confirmed what you said about relatively rough grit (120-200g) on the part of the spring where the tang rides.
Click to expand...
When he talks about polishing the spring he is talking about what he had just ground down for tension. He makes it clear in the video how to avoid galling of the tang and spring.

You may have to watch the entire video again a few more times. I have watched it at least a dozen times and refer back to it at times.
 
You must log in or register to reply here.
Back
Top