quality control checkilst

H

HSC ///

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Nov 7, 2012
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Would you guys help me develop a QC checklist for fixed blades?

This morning I went to hone a knife edge that is shipping out tomorrow to a repeat customer who is a user.
This knife was fully assembled and ready to go.
I thought I would do a quick little manila rope test.
I was disappointed to find it didn't cut that great.
I measured the bevel geometry and decided I needed to reprofile it, which I did.
Anyway all is well and the knife cuts beautifully, and I learned a few things along the way.

Knife-making is a series of steps, some with precision and progression.

As a bladesmith student trying to improve my work, I'm going to come up with a quality control checklist for fixed blades.
A QC check off throughout the process that I can refer to.
The list would contain some obvious things and maybe some things maybe not so obvious.

I'll publish it when completed and post here for others to use.

Would you guys sound off with replies as to something that comes to your mind?
Of most importance would be around the ricasso area I think but anyting realted to a handle or guard would be good but don't be limited by these suggestions.
Anything that has helped you or could help someone else, let's keep this to fixed blades.

I'll go first : Measure and verify your bevel edge geometry before you put on a handle or guard.

thank you
 
It's encouraging to me to see this kind of thread. If a custom maker isn't provide a real value to the end user for their work there's little reason for a person to buy our work. Walmart sells knives pretty cheap, we need to justify our existence by providing a demonstrably better knife and quality is where it's at. Custom makers selling shoddy work do us all a disservice because the buying public that uses our work can be put off of custom knives if they get a lemon. And, for better or for worse, it is the lower price "user grade" knives that are most likely to really get used and a lot of that falls on the newest makers. High quality simple knives are a great place to cut your teeth.

1: you have to know your heat treat is right. If you don't *know*, you're not ready. This is a long subject, there are a lot of ways to go about this.

2: as the OP mentioned, is the blade geometry what you intended. I measure the edge thickness before sharpening and there is a narrow acceptable range for a particular pattern.

3: Is the edge angle appropriate. If you're just guessing at the angle, well, a lot of folks do that with the expectation the end user will set it the way they want it. But I recommend controlling the angle and level of sharpness.

4: Is the edge sharp. I haven't found a 100% fool proof process so I still QC every edge on every knife that leaves my shop. First I look and feel for any burr. I look for any shiny spots under bright light. And then I test for sharpness in several places along the edge. A poor quality edge might be reasonable on an inexpensive factory knife and (ironically) a very expensive collectable art piece, but I think it's a pretty reasonable expectation a knife intended to be used should be sharpened correctly. It's also my opinion that grinding the edge wet is pretty cheap insurance against burnt edge.

5: Do the scales fit the tang correctly

6: I QC for undulations and flaws in the geometry before putting the knife together, but I inspect the finish one last time before putting it in the sheath for the last time. I look under two kinds of light for scratches and other blemishes, I blow the sheath out real well and I clean and oil the blade (very thin film) one final time. You don't want grit in the sheath. I'm also careful to remove any finger oils that may have been left on the blade so there are no stains when it gets to the end user.

Other areas makers should look at are even bevel height and even plunge. You should also sight down your grinds and reflect a bright light across your bevels and look for undulations, gouges and waves. They *will* be there, and if you have a good eye you can find them on any piece, but you have to know where *you* are and where you want to be...

Are the secondary edge bevels even?

Did you accidentally grind a shallow recurve when you sharpened it that will cause issues later on to a owner using oil stones?

Does the sheath fit properly?

Is it packed in the shipping box in a way that a box, if dropped or crushed, could end up with the tip of a blade poking out removing parts of the postal workers?

Is the shipping address correct (the address in paypal is often old)?

There are lots of other areas regarding the quality of a good blade such as gaps under the scales, wonky tips, improperly installed fasteners, and also things like design issues or material choices, but that's getting into another kind of thread.

I'd really love to hear some of the other makers input on this :thumbup:
 
A simple one, maybe more for newer makers like myself: Check the blade in several different lights, to make sure there isn't a rogue scratch.
 
Have you used the knife.
Knives are different than most goods, in that the difference between a brand new one and a lightly used one is pretty much non existent.

I only make kitchen knives, and as someone who is a reasonable cook, I will put any knife through its paces.

Will it mince garlic well?
Are there any spots that dont seem to cleanly separate soft materials like chives?
Is there too much drag when cutting meat?
Does the edge feel like its deflecting?
Does moving the tip feel awkward and clumsy?

As someone who has used some pretty high end custom kitchen knives along with many many others, I feel like I have a reasonable idea of how a good knife should feel.

This is more of a diagnosis step, because I know if say, its failing to seperate soft foods, there might be a small hollow in the blade and I need to do some regrinding.
 
I have a few that I do while I'm working on a knife. I haven't written them down as a QC checklist, but I think it's a great idea. Some of my points have been covered above, so I won't repeat them.

1) distal taper even
2) grinds even
3) plunge even on both sides
4) fronts of the scales lined up
5) pins centered on the tang
6) pins spaced evenly
7) lanyard hole aligned where I want
8) sanding marks parallel with no J hooks
9) no gaps
10) no excess epoxy on Ricasso


That's all I can think of for now...
 
Nick EBK said:
A simple one, maybe more for newer makers like myself: Check the blade in several different lights, to make sure there isn't a rogue scratch.
Click to expand...

This is a real good one. It's amazing how different a blade will look under different light sources. The shop is full of florecent lights and the grinder has even more from a few different angles but nothing beets going outside into the sunlight. I learned my lesson after finishing a knife and went out side to take a picture. Wth where did thoee scratches come from. Back into the shop I go and wait where did the scratches go now.
 
Great idea H. This should be useful for all makers I would think.
Just reading through what is here so far, it appears to want to split into two different categories:
1. Functionality testing.
2. Good design.

I think you are focused on #1 and that makes sense. #2 is just going to need a lot of experience and/or study.
My contributions to #1:

Trying not to duplicate too much what has been said...

1. Blade, taper, grind and edge all straight. If these are right then a lot of problems are eliminated.
2. Fit and finish up to par.
3. Edge bevel: This gets tricky. There is a lot of variation here. What is the knifes intended use? This should inform the edge bevel. Experience and study...
4. Will it push cut paper the full length. This is what I test for with my chef knives.
5. Pay attention to your customer feedback.

I would also love to see a list of standard repeatable tests one might do for a blade. There are destructive tests that one can do to test your blade in general, but there should be a list of non-destructive tests one could perform on each blade before shipping out.
 
75% of my focus is on cutting geometry and cutting performance so I will just share my process on that with kitchen knives.

Profile...does the edge make board contact the way it was designed to? I take the blade to the board and go through the motions. push cuts, pull cuts, rocking, see how much of your blade is truly flat and what the curve is going to feel like.

Bevels centered...Is the bevel centered along the entire length of the blade?

Symmetry...I take a dozen or so measurements with my verniers at various spots on the blade, these measurements should be consistent with my predetermined cad measurements.

Doing this test by eye is the most difficult. It bends a little left with one eye closed and bends a little right with the other eye closed then you know its kinda straight...lol. So for symmetry I rely on numbers not eyes.

Final sharpening...I simply dont put a final edge on my knives until it is time to box one up and send it out. That means I need at least an hour to get a knife ready to be shipped. Set the secondary bevels on a 220 belt at low speed. Use my atoma plate to make sure my 150 grit brick is flat (nubatama bamboo). Youve gotta make sure your tools are right. Set my bevels on the brick, then my 1500 shapton until burr is raised, then finish on my 10K imanishi. This isnt the best edge for a working kitchen knife usually but it is impressive and mirror polished, hair shaving, tomato skin defying, bad ass edge. It is easy enough for the customer to touch it up on a more working duty stone if they wish. The time and effort it takes doing this by hand on the stones will really let you know the quality of an edge.

on a side note: go the extra mile and send one of your completely finished knives to a well known knife sharpener....the kind that has about 10 grand invested just into sharpening alone, and get yourself a really good evaluation.
 
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