Tumbled vs. Non-Tumbled Blades

T

TheDrifter

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Jan 14, 2008
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I was sitting around tonight wondering about why blades were tumbled (i.e. the area on the edges of the tang is rounded off). I have seen a few posts on here that seemed to suggest that non-tumbled blades were better but no clear reasons were given. I also inspected two of my sodbusters, a Queen and a Case, both Jr.s. Like the posts said, the Case blade was tumbled and the Queen blade was not.

Is there some type of advantage to having the non-tumbled blades? Or is non-tumbling or tumbling just a matter of preference or a more traditional looking knife? Does anyone know about this? Thanks.
 
Hi,

There really isn't any real world mechanical advantage to non-tumbled or tumbled blades. I suppose there is a very, very tiny amount of stress relieving in a tumbled piece of steel. But for practical purposes, it's nothing.

Real world reasons to tumble would be, cleaning stuff off of the blades like mill scale, HT scale (though most commercial HT is done in controlled atmosphere ovens), washing of oils and coatings on or off, de-burring of sharp edges, and polishing.

Reason not to tumble, takes time and costs money. Wanting or needing crisper edges on the finished part. Possible damage to tumbled parts.

dalee
 
Tumbling as you cal it- can cover up any imperfections and little "mistakes" in grinds and shaping too..

G.
 
dalee100 said:
Hi,

There really isn't any real world mechanical advantage to non-tumbled or tumbled blades. I suppose there is a very, very tiny amount of stress relieving in a tumbled piece of steel. But for practical purposes, it's nothing.

Real world reasons to tumble would be, cleaning stuff off of the blades like mill scale, HT scale (though most commercial HT is done in controlled atmosphere ovens), washing of oils and coatings on or off, de-burring of sharp edges, and polishing.

Reason not to tumble, takes time and costs money. Wanting or needing crisper edges on the finished part. Possible damage to tumbled parts.

dalee
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:thumbup::cool: There you have it.
 
Ice Tigre said:
Tumbling as you cal it- can cover up any imperfections and little "mistakes" in grinds and shaping too..

G.
Click to expand...

Exactly true. If you soften all of the points where intersecting geometric lines meet, grind symmetry is not as easy to define. This actually saves more hands on time and turns much of the finishing work over to machines. I think this appeals to the majority of collectors because "shinier is better".
 
KnifeHead said:
Exactly true. If you soften all of the points where intersecting geometric lines meet, grind symmetry is not as easy to define. This actually saves more hands on time and turns much of the finishing work over to machines. I think this appeals to the majority of collectors because "shinier is better".
Click to expand...

IF tumbling is used to remove scale and break sharp edges(hot spots), and then a proper polishing (hand/machine satin) job is done, you get the best of both worlds.

Unfortunately, I have never seen a production company do this.

Best Regards,

STeven Garsson
 
So, basically tumbling is done to create a "smoother" look to the blade, which some collectors prefer. Or it is used to cover grind or shaping defects. I kind of got the feeling that it was mostly an appearance thing. Thanks, everyone.
 
TheDrifter said:
So, basically tumbling is done to create a "smoother" look to the blade, which some collectors prefer. Or it is used to cover grind or shaping defects. I kind of got the feeling that it was mostly an appearance thing. Thanks, everyone.
Click to expand...

Hi,

No, not quite.:D If you tumble a part or not, that is a manufacturing process decision. Think of it this way. Case will have 10,000 clip point blades to finish today. Hand work alone ain't going to make that happen. This is why Case tumbles blades. Tumbling can cause defects, but it won't cover them up. Making defects go away or get "blended in", is the one of the things that needs to be done by the human hands of those rushed craftspeople. A custom maker will need to finish one blade today. This is why he doesn't need to tumble.

If you like the look or not, that's cosmetic preference.;)

dalee
 
Tumbled blades make no difference in performance than non tumbled. It's a fit & finish thing.
crisp looks nice.

P1010243.jpg
 
dalee100 said:
Hi,

No, not quite.:D If you tumble a part or not, that is a manufacturing process decision. Think of it this way. Case will have 10,000 clip point blades to finish today. Hand work alone ain't going to make that happen. This is why Case tumbles blades. Tumbling can cause defects, but it won't cover them up. Making defects go away or get "blended in", is the one of the things that needs to be done by the human hands of those rushed craftspeople. A custom maker will need to finish one blade today. This is why he doesn't need to tumble.

If you like the look or not, that's cosmetic preference.;)

dalee
Click to expand...


Up until the mid 1980's, Case did hand polish all of their blades. There were no tumbling machines in their plant. In about 1985 they changed their manufacturing processes to include tummbling - now there is no hand polishing and it is all done by tumbling. There is a final buffing done by hand but its more for just cleanup.

Queen still hand polishes, and you can see that the lines on their blades are crisp.
 
Blades are tumbled to meet production demands while keeping labor cost to a minimum per blade, plain and simple.
 
Well that clears it up. Tumbling = a process that can substantially speed up the finishing of blades over hand finishing when production demands are high in terms of volume. So, generally non-tumbled blades would indicate a greater emphasis on hand finishing, which could indicate a smaller volume of production or higher quality manufacturing standards. Tumbling allows the blade to be cleaned up after other steps in production without the higher cost of having to employ substantial hand finishing. Essentially a volume v. quality issue
 
I never really understood the differences between tumbled blades versus non-tumbled until I compared my Queen Cattle King to a Case Jumbo Stockman I just bought.

While the Case blades have beautiful polished surfaces , the swedges are "soft" and I don't like the rounded corners where the tang meets the spring ( when open). The Queen knife has nice sharp edges.

KnifeHead actually pointed this out in an old post.
 
You got it Drifter, watch the video that Mark posted, it will give you an idea of the volume of blades being polished.





BTW hawk, you didn't spell korrect right :D
 
As pictures in this thread have shown, un tumbled blades give a 'crisper' appearance,but there IS a downside:pocket tear/snagging is a lot worse than with a tumbled blade which has a smoother tang. My Queen Utility has a sharp edge tang whereas my CASE Slimline Trapper nestles peacefully without snagging.Both very much liked knives though:D
 
4ever3 said:
You got it Drifter, watch the video that Mark posted, it will give you an idea of the volume of blades being polished.





BTW hawk, you didn't spell korrect right :D
Click to expand...
:D

I wouldn't let tumbling deter me from getting a Case. My Copperlocks and mini trapper are that way, and I think f/f on the copperlock is great.
 
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