Why Buy a CRK?

[knarfeng]

So I have a question as I'm not a machinist and have zero knowledge about CNC machines other than what they are and what they do.

How does CRK get such tight and controlled tolerances? Is it due to better equipment, better data/coding input, better materials, better design, or maybe more hand finishing and attention to detail?

Not my area of expertise, but I'll take a high level stab at it. I've set tolerances on a few parts here and there, so I'm not totally unaware of the issues.

Aside from the CNC machine, the tooling and the bit heads must be made to tighter tolerances and replaced more frequently because they wear in use. Wear that would not be noticed if you were holding a 0.005" tolerance is enough to screw up a part if you are holding 0.0001". Obviously replacing these items more frequently adds to the manufacturing cost.

The particular CNC machine being used is also important. There are various CNC machines with varying capabilities as regards holding tolerances. The machines capable of tighter tolerances take significantly longer to machine a given piece.

The precision significantly increases the cost of manufacturing the knife.

 

[Mick_1KRR]

I have owned several. They are no better than the myriad of nicer modern CNC made folders out there. Their claim to innovation is diminishing daily as the next high end maker puts out the next greatest knife.
They have positioned themselves in the middle of the road where next level less expensive knives are passing them by with tighter CNC tolerances and the same quality materials plus in many cases much better steel.
I recently picked up watch repair as a hobby, if you work under magnification you will only be lying to yourself to say CRK is really better than the average ZT in precision and materials.

See now this is what i like, once in a while amidst all the browsing and reading, sometimes you get a good dose of comedy on your lazy Sunday afternoon. I can't even decide what's funnier, the comparison of your 'average' ZT to a CRK, or the fact that you think you can measure tolerances just because you zoomed in a little with some magnification. No digital callipers or measuring tool needed here folks, just gime a bit of zoom and I'll eyeball it.

 

[Sharp & Fiery]

^ Now that was comical. Thanks for making me smile. M Mick_1KRR

 

[bhyde]

Not my area of expertise, but I'll take a high level stab at it. I've set tolerances on a few parts here and there, so I'm not totally unaware of the issues.

Aside from the CNC machine, the tooling and the bit heads must be made to tighter tolerances and replaced more frequently because they wear in use. Wear that would not be noticed if you were holding a 0.005" tolerance is enough to screw up a part if you are holding 0.0001". Obviously replacing these items more frequently adds to the manufacturing cost.

The particular CNC machine being used is also important. There are various CNC machines with varying capabilities as regards holding tolerances. The machines capable of tighter tolerances take significantly longer to machine a given piece.

The precision significantly increases the cost of manufacturing the knife.

Pretty much nailed it..

There are a few more factors involved. Achieving tolerances specifications requires that the makers have an understanding of process control and what technologies to use to make the part.
If it's a simple matter of using just a CNC milling machine, loading a piece of stock and hitting the cycle start button then anyone could do that..It's just not that simple. If I use the scales on a given CRK for an example, they don't initially come in as a raw piece of stock..That is no good..It might be to the right thickness generally speaking but it's definitely not flat and in most cases, not parallel either. Flatness and parallelism are tightly linked if you have secondary and tertiary etc operations. So, the scales are ground or lapped flat from thicker stock and that is very tightly controlled. Having this controls the mechanism on the inside of the knife..Pivot and rear backspacer..If the stock isn't flat then you have an issue with binding because the fasteners are trying to pull the material flat.
This thought process is carried through the assembly..I was told what the spec was on the blade flatness before the hollow grind is applied (CRK grinds after heat treat by the way). IIRC, flatness and parallelism is generally within .0002in. Machining operations will affect that after but that is mitigated through other process controls.
Changing out tooling on a regular schedule or when the machinist notices some deviation in runs helps maintain this high quaility spec..Ya not going to run to harbor freight and pic up your cutting tools, machine equipment etc for making this stuff..Every manufacturer knows this..It's a constant battle in machine tool technology..The machines do not last forever..neither do the tools and that is before you add the human element. The ones that make mistakes that cause costly repairs..Such as slamming a spindle head into a horizontal pallet costing months of downtime in machine repair and fixture rebuild.

Don't make the mistake of thinking CNC's are just giant microwaves in simplicity..You don't put in a piece of stock, set the timer for two minutes..Wave the blueprint in front of the controller and DING! Your part is done..Although, there are a number of people that believe it is just that simple.

 

[nwmetalbug]

You also have whats known as tolerance stack where for instance one part is at the higher end of a given size and the adjoining part is at the smaller allowable size they wont fit together so its a lot of hand fitting with go-no go gauges. time is money

 

[Ron Sabbagh]

Pretty much nailed it..

There are a few more factors involved. Achieving tolerances specifications requires that the makers have an understanding of process control and what technologies to use to make the part.
If it's a simple matter of using just a CNC milling machine, loading a piece of stock and hitting the cycle start button then anyone could do that..It's just not that simple. If I use the scales on a given CRK for an example, they don't initially come in as a raw piece of stock..That is no good..It might be to the right thickness generally speaking but it's definitely not flat and in most cases, not parallel either. Flatness and parallelism are tightly linked if you have secondary and tertiary etc operations. So, the scales are ground or lapped flat from thicker stock and that is very tightly controlled. Having this controls the mechanism on the inside of the knife..Pivot and rear backspacer..If the stock isn't flat then you have an issue with binding because the fasteners are trying to pull the material flat.
This thought process is carried through the assembly..I was told what the spec was on the blade flatness before the hollow grind is applied (CRK grinds after heat treat by the way). IIRC, flatness and parallelism is generally within .0002in. Machining operations will affect that after but that is mitigated through other process controls.
Changing out tooling on a regular schedule or when the machinist notices some deviation in runs helps maintain this high quaility spec..Ya not going to run to harbor freight and pic up your cutting tools, machine equipment etc for making this stuff..Every manufacturer knows this..It's a constant battle in machine tool technology..The machines do not last forever..neither do the tools and that is before you add the human element. The ones that make mistakes that cause costly repairs..Such as slamming a spindle head into a horizontal pallet costing months of downtime in machine repair and fixture rebuild.

Don't make the mistake of thinking CNC's are just giant microwaves in simplicity..You don't put in a piece of stock, set the timer for two minutes..Wave the blueprint in front of the controller and DING! Your part is done..Although, there are a number of people that believe it is just that simple.

excellent post. This is extremely helpful - cuz I've always wondered myself....If the CNC machine does the job by itself or if there is still some "artistry" to it.

so for a layman like myself...it sounds like CNC machining is just a "method" that an artist has to master to make an excellent knife...much like learning how to forge/heat treat/grind, etc.

The new CNC masters like Brian Nadeau and Bill Koenig are turning out great knives. But CRK was the innovator for CNC machining (as far as I am concerned) and still continues to improve on its' manufacturing and design. I'll always have a CRK in my stable.

 

[bhyde]

excellent post. This is extremely helpful - cuz I've always wondered myself....If the CNC machine does the job by itself or if there is still some "artistry" to it.

so for a layman like myself...it sounds like CNC machining is just a "method" that an artist has to master to make an excellent knife...much like learning how to forge/heat treat/grind, etc.

The new CNC masters like Brian Nadeau and Bill Koenig are turning out great knives. But CRK was the innovator for CNC machining (as far as I am concerned) and still continues to improve on its' manufacturing and design. I'll always have a CRK in my stable.

There is an approach and artistry to it..absolutely.
Pushing a button isn't magic at all..There can be alot of people involved in that part people take for granted..and there can be alot of scrap before lessons are learned. Precision isn't an afterthought; It's the culmination of forethought, experience and approach to making any part.

I need to get over and see Bill Koenig..Haven't been over there yet.

 

[aleforme]

That's pretty much it. It costs time and money to meet those targets. That can mean more time on the machine or more batches of parts rejected if they don't match the decimal places. Never mind the time taken to design and prototype a new thing.

It's "relatively" easy to make one thing to a tight tolerance. It gets a lot more complex when the thing you're making is made of a bunch of parts you make to a particular tolerance; they all have to match up.

Not my area of expertise, but I'll take a high level stab at it. I've set tolerances on a few parts here and there, so I'm not totally unaware of the issues.

Aside from the CNC machine, the tooling and the bit heads must be made to tighter tolerances and replaced more frequently because they wear in use. Wear that would not be noticed if you were holding a 0.005" tolerance is enough to screw up a part if you are holding 0.0001". Obviously replacing these items more frequently adds to the manufacturing cost.

The particular CNC machine being used is also important. There are various CNC machines with varying capabilities as regards holding tolerances. The machines capable of tighter tolerances take significantly longer to machine a given piece.

The precision significantly increases the cost of manufacturing the knife.

Wow, thank you for these responses. I really appreciate being able understand a little bit more about the process. I think the above really helps people understand what is meant when people say CRK has such "tight tolerances". We see this all the time and this helps put some true meaning behind it.

 

[Hanover Fiste]

I have carried a Sebenza Small 21 or Large Classic as my EDC for the last 5 years or so. They have become the only knives I carry 98% of the time. I do have fixed blades that I will also carry when camping or working but the CRKs are always still with me.

CRKs are simply a joy to use in addition to their effectiveness at cutting. They look good. Their simplicity belies the sophistication of the design and manufature. They feel good to me. The smooth action and solid lockup. They slide into my pocket well. The smooth finish doesn’t chew up my pants yet still offers grip. They also don’t look particularly aggressive in the pocket or hand.

For me the Sebenza is an example of a perfect knife. Not THE perfect knife, mind you, but A perfected design. IMHO there is nothing CR could add or subtract that would make the Sebenza a better knife. That does not mean that there is nothing negative about CRK knives. Their positive and negative attributes have been enumerated multiple times already and let me say I agree with just about everything said so far. For me, none of the negatives are deal breakers.

When I first laid eyes on a Sebenza more than 30 years ago I knew it was a grail for me. It took me twenty years but I finally was in a position to buy one (or three). Since then my knife ‘collecting’ has tapered down significantly. AAMOF the only knives I am really interested in now are custom fixed blades. My folder itch has been most satisfactorily scratched.

So that is why I like my CRKs. In them I found my best tool that I carry everyday.

 

[sliceofaloha]

Well you started out with a heck of a Sebenza. The Diamond Plate versions are hard to come by. Took me months to find one.

Just curious, were they able to treat the Diamond Plate scale? I'm under the impression they can't mess with those given the milling?

You are correct, I did ask and they won't blast due to the polish of the cut outs.

 

[knarfeng]

See now this is what i like, once in a while amidst all the browsing and reading, sometimes you get a good dose of comedy on your lazy Sunday afternoon. I can't even decide what's funnier, the comparison of your 'average' ZT to a CRK, or the fact that you think you can measure tolerances just because you zoomed in a little with some magnification. No digital callipers or measuring tool needed here folks, just gime a bit of zoom and I'll eyeball it.

I agree with your assessment of the post.
The account of the member you quoted has since been banned by one of the mods. The clown was a returning troll.

 

[aleforme]

You are correct, I did ask and they won't blast due to the polish of the cut outs.

Thanks, that's what I figured. Mine is in great shape but it does get carried.

 

[jceckrosh]

I traded for my first CRK and then said "Why not buy 3 more."

So I am still in a honeymoon phase, but the more I handle them the more impressed I am. I can absolutely see why they would not be for everyone, but just judged on engineering, fit and finish, sharpness/grind, simplicity - they are pretty impressive.

 

[Steely_Gunz]

I'm actually really looking forward to snagging a Sebbie around the early fall time period. I've been on a bit of a knife buying tear as of late. I was able to buy one of the ZT 303 monsters that I had no idea they were producing again to scratch over built tank of a knife itch. I think when the Honeymoon is over with that beast I'll be ready to really enjoy a more refined edc and save the gigantic knives for my infrequent woods walks.

 

[Scott K.]

I use me Sebenza (let alone any of my knives) quite a bit, and I am not easy on them. The blade steel/edge holds up! Also, every time I need a tune up, I only pay shipping and it comes back looking new and scary sharp!

 

[sliceofaloha]

^Are you using the Popeye editor?

 

[Sonnydaze]

The Sebenza was The first frame-lock (ie Reeve-Integral-Lock) and is still perfection in form and function...

It doesn't get any better....PERIOD.

 

[kniferbro]

Insightful take on it. Looking at the CRK IG account, they haven't even posted since Jan 22, likely because they don't need to. They don't have social media auctions, or lotteries, or WIP porn shots for days and days. They look like they only post when something is going on. So I agree, a CRK probably does not have the flavor of the month like generating potential of some other knives - no exclusivity look at me value. CRK is not here to make someone feel like a beautiful and unique snowflake.

What's funny is a CRK shot garnered the most likes of anything I have put on my IG. So while CRK is not putting out a lot of content, it looks like CRK fans are looking for CRK content.

You need to follow Tim if you want the BTS CRK stuff!

 

[willard0341]

Im waiting on a rental car to depart for baton rouge this morning. I start a 28 day trip on a boat tomorrow and im packing this small. (Along with a couple of traditionals)
I just wanted to add i like the stronger detent that wears in nicely over the years. I am glad we can celebrate nice knives and yoga pants. Cheers

 

[jceckrosh]

Im waiting on a rental car to depart for baton rouge this morning. I start a 28 day trip on a boat tomorrow and im packing this small. (Along with a couple of traditionals)
I just wanted to add i like the stronger detent that wears in nicely over the years. I am glad we can celebrate nice knives and yoga pants. CheersView attachment 1107207

Nice bag. I have two, and they just get better over time as well.