Case Delrin/synthetic cracks

sailfish

sailfish

Joined
Jan 1, 2019
Messages
1,756
So I picked up a brand new yellow Sod Buster on the way home from work yesterday but I didn't notice until closer observation later that there was a short crack in the synthetic handle off the center pin that ran perpendicular to the backspring. I went back to see about exchanging it but every single one of their stock had the exact same thing. I did some research when I got back home but all I could come up with was this thread here: https://www.bladeforums.com/threads/case-delrin.1585222/

It got me wondering if this center pin crack is just something to be expected on a $29 work knife, even a new one? From the sounds of that other thread it seems like such a crack could develop down the road even if I found one that didn't have it. But it also seems that there's low risk of it spreading or actually ever breaking. What are your experiences with this?
 
The crack in question.

UbaTlC7.jpg
 
It's common as an aesthetic issue on this knife. Mine is pictured below (3137 CV). But I've never had any functional issues as a result of it. It seems to crack just so far, and then becomes essentially forgettable. I've never worried about it. The holes for the backspring's anchor pin are drilled very close to the edge of the cover, which I think is most of the reason it happens. But functionally, it has never been an issue for mine.
S1Q47zX.jpg

V184HJ9.jpg
 
Last edited:
I wouldn't expect it to spread.
When something develops a crack a hole drilled in the right place will stop the crack in its tracks.

It seems in this case the hole responsible for the crack is also keeping it from spreading.


This got me thinking I should probably check my sodbuster JR in black delrin, to see if it's cracked.
 
Last edited:
Kevin-B said:
Beautiful collection! I really need to get myself a sodbuster aswell. I’m still deciding if i should go for Case or GEC. I’ll probably end up getting both.
Click to expand...
I have to humbly apologize! Ma' used to tell us to turn our tongue 7 times in the cheek before speaking!
In fact 3 are cracked, all the same place same side! 😫
Chances are the cracks happened after I received the knives, because I inspected them when opening the box!
No crack yet on the red or grey.
cracks.jpg
 
Last edited:
And speaking of 'common on this knife', here's a look at my 2138 SS large soddie. Lo and behold, there it is again. I'd never noticed it, until now. Again, as with my yellow one, I haven't noticed any functional issues with it.
VxMRMn5.jpg

eY7eyNr.jpg


And somewhere, I have a small soddie in black delrin (2137 SS) as well. I'll have to look for it there as well.

On the black ones, the crack isn't nearly as visibly obvious. I had to feel with my thumbnail to detect it. And the zoom-in provided by my phone's camera further revealed what I hadn't seen before.
 
Well. It's looking like a crack by the center pin is par for the course on these synthetic sod busters. Guess it's not worth the trouble of hunting down an exchange or anything. An unfortunate design flaw that my bone scale sod buster fortunately doesn't suffer from.

On the plus side, the crack doesn't seem to spread or chip and these are about as much of bare bones working tool knife as you can get. So as as the scales get scratched and dinged and discolored and the blade patinas, the little crack will detract less and less, possibly even adding to the overall antique appearance of the knife.
 
Luckily Delrin is pretty tough stuff. I seem to recall that it was originally used for bushings in stuff. They also make guitar picks out of it. The guitar picks are pretty durable too.
 
I've got a few Case Sod Buster and Case Sod Buster Jr. knives
Sod Buster Group 5 .jpg
and after just now checking all of them, only the two small yellow Sod Buster Jr. knives have the subject crack. They've both been like that since I've had them and I've known that the crack is quite common on these knives. When in rotation, I use them quite a bit with no failure in either one.
 
sailfish said:
So I picked up a brand new yellow Sod Buster on the way home from work yesterday but I didn't notice until closer observation later that there was a short crack in the synthetic handle off the center pin that ran perpendicular to the backspring. I went back to see about exchanging it but every single one of their stock had the exact same thing. I did some research when I got back home but all I could come up with was this thread here: https://www.bladeforums.com/threads/case-delrin.1585222/

It got me wondering if this center pin crack is just something to be expected on a $29 work knife, even a new one? From the sounds of that other thread it seems like such a crack could develop down the road even if I found one that didn't have it. But it also seems that there's low risk of it spreading or actually ever breaking. What are your experiences with this?
Click to expand...
My guess is that Case does the drilling from one template on all of these, and then just put them together. The only reason for that rivet to cause a crack is if all the holes are not properly matched and therefore make tension between the holes/rivets. Probably to be expected on a cheaper model
 
Another thing to consider - notice how Case now uses the term "composite" to describe the cover material used on some of these knives instead of "Delrin". The two yellow Sod Buster Jr. knives show above in my group are "composite" not "Delrin". The cover material on the large liner lock Sod Buster show middle top in my picture is "Delrin" with no cracks. Not sure about the orange and yellow large Sod Buster knives and not sure of the small orange Sod Buster Jr. knife. At the time of purchase, Case was listing the small black and small red Sod Buster Jr. as "Delrin" but who knows what cover material "Delrin or Composite" is used through out each production cycle.
 
Well, it looks like my 2137 SS Jr. Soddie escaped the issue. When I first picked up this one in a clamshell package at Lowe's years ago, I was impressed with the build on it. Had maybe the best-ground edge I'd seen in a long time (and I've since thinned & polished it some more), and was fully apexed all the way to the pointy tip. So, it seems this one has been a peach all along. :)
gIarv1n.jpg

Tz8UnSV.jpg

6k26o4E.jpg
 
Obsessed with Edges said:
Well, it looks like my 2137 SS Jr. Soddie escaped the issue. When I first picked up this one in a clamshell package at Lowe's years ago, I was impressed with the build on it. Had maybe the best-ground edge I'd seen in a long time (and I've since thinned & polished it some more), and was fully apexed all the way to the pointy tip. So, it seems this one has been a peach all along. :)
gIarv1n.jpg

Tz8UnSV.jpg

6k26o4E.jpg
Click to expand...
Maybe the hammer fisted guy working on yellow top covers only makes extras on blue and black uns... and gets on holidays sometimes! 😉
 
Pin cracks are common on all brands, patterns, am scale material. The scale is thin there, and it makes a pretty pronounced transition in thickness. That leads to stress. In any event, it shouldn't be present on a new knife.
 
Jolipapa said:
Maybe the hammer fisted guy working on yellow top covers only makes extras on blue and black uns... and gets on holidays sometimes! 😉
Click to expand...
It has occurred to me, that maybe the peening of the pin is playing into it, aside from the hole being drilled too close to the edge of the cover. I noticed the ends of the pin on my yellow Jr. Soddie (with a crack) are spread a bit wider than seen on my black Jr. Soddie (with no crack). Back-to-back comparison pic below. Maybe one hammer-tap too many, in peening, is stressing the cover a little too much. So, maybe 'hammer fisted' is actually a factor there.
bC3RjtY.jpg
 
You must log in or register to reply here.
Back
Top