Grinding for hours...

[Stromberg Knives]

Hi guys!

I'm curious. How long does it take you to grind for example a standard sized drop point hunter in a non-extreme steel type.

I understand that type of steel, size, thickness etc comes to play. I'm just trying to get a feeling if I'm doing something completely suboptimal.

For example, when I grind a 4 inch FFG hunter in 3mm Niolox, with a fresh 36 grit Cubitron 984 - it takes forever.

Yes, I grind everything post heat treat (I get better plate quench that way). But still, one blade takes me around 3-5 hours and a couple of belts. And I'm even pushing it pretty hard since I'm running my grinders wet.

And the 3-5 hours doesn't include finishing belts either.

I'm thinking about oil quenching my thicker (non kitchen type) Niolox blades instead, and pre HT grind them.

Feel free to give me your thoughts on the matter!

 

[J. Doyle]

That's a REALLY long time.

I can grind a blade that size easily in 10 minutes.....less if you're talking about only the 36-60 grit rough work.

Obviously if someone is brand new to grinding it will take a while to get things figured out. But 3-5 hours seems really excessive to me especially for just a rough grind.

 

[Frank Niro]

Well Niolox you say? I have never used that and now never will. Just because it requires that much doesn't necessarily make it a good steel for knives. The customers will have a nightmare when it comes to sharpening.
Frank

 

[john april]

give us more info. are the tangs tapered, and what grit are you going up to to equal the 3-5 hours. is doing the profile from a billet included in your time ?

 

[Stromberg Knives]

That's a REALLY long time.

I can grind a blade that size easily in 10 minutes.....less if you're talking about only the 36-60 grit rough work.

Obviously if someone is brand new to grinding it will take a while to get things figured out. But 3-5 hours seems really excessive to me especially for just a rough grind.

Haha, 10 minutes. I see some room for improvement here. And yes, I'm talking about 36-60 grit.

Well, I'm by no means an advanced grinder, but I have ground a fair number of blades by now. But still, a bad technique repeated to perfection is still a bad technique.

When trying to analyze my grinding technique: do you grind in small steps and keep raising the grind line? I've been grinding it all at once, which could be part of my problem. It seem to generate a lot of unnecessary heat and not so much material removal since I'm grinding a big flat spot (which keeps getting bigger and bigger as I progress).

 

[Stromberg Knives]

Well Niolox you say? I have never used that and now never will. Just because it requires that much doesn't necessarily make it a good steel for knives. The customers will have a nightmare when it comes to sharpening.
Frank

Yes, I'm new to this steel, I've only ground a couple of them yet. But I don't want to dismiss it if it's actually my grinding technique that's at fault here.

But you're right, I'll be making some tests from a customer perspective. Good point!

 

[Stromberg Knives]

give us more info. are the tangs tapered, and what grit are you going up to to equal the 3-5 hours. is doing the profile from a billet included in your time ?

I may be misunderstanding your question, but why would a tapered tang matter when grinding bevels? No disrespect, just curious. But no, there are no tapered tangs here.

In my 3-5 hours I'm up to 60 grit. But I would say that 80-90% of the time is working the 36 grit to the point when my hands are completely sore. So in general, I'm never completing a bevel grind in one session. I need to stop for food and rest, haha.

It's stock removal and the blank has been profiled, heat treated and ground flat (on belt grinder and disc grinder).

 

[kuraki]

An hour start to finish if I don't make any mistakes. But I grind pre heat treat with everything 3mm and over. Especially on air hardening steels as I've gotten a process down that generally allows me to pick right back up at the grit I left off on after ht going right to a 220 cork belt.

 

[Willie71]

Hi guys!

I'm curious. How long does it take you to grind for example a standard sized drop point hunter in a non-extreme steel type.

I understand that type of steel, size, thickness etc comes to play. I'm just trying to get a feeling if I'm doing something completely suboptimal.

For example, when I grind a 4 inch FFG hunter in 3mm Niolox, with a fresh 36 grit Cubitron 984 - it takes forever.

Yes, I grind everything post heat treat (I get better plate quench that way). But still, one blade takes me around 3-5 hours and a couple of belts. And I'm even pushing it pretty hard since I'm running my grinders wet.

And the 3-5 hours doesn't include finishing belts either.

I'm thinking about oil quenching my thicker (non kitchen type) Niolox blades instead, and pre HT grind them.

Feel free to give me your thoughts on the matter!

What type of grinder do you have?

 

[john april]

the first sentence says grinding a drop point hunter, which has a tapered tang. i was not sure if that and profiling was included in your time. it did not mention bevels only. 36 grit just doing bevels maybe 15 minutes for me.

 

[butcher_block]

4 inch mini chef (XHP 3/32 th\ick rc 63) bevels finished in about 30 min (ready to etch my mark) on the other hand a 3 inch blade straight razor might take me over an hour dependig on how hollow the grind
edit to add lowest grit i use is 50 as i think 36 skitters around too much on a hardened blade and i like the control of the 50 grit before and after HT

 

[Horsewright]

With John, bout 10 mins to have er at 60 grit, ready to ht. Nuther 10 after ht, maybe 15 if I got to fix something.

 

[Kevin McGovern]

3.4- 4" drop point hunter- 15 minutes tops to 120 grit pre heat treat finish. I move up the grind from edge to spine. I think what you are doing going at it in one shot may be your problem. I know I would be doing a lot of correcting if I did that.

 

[HSC ///]

the rough grit bevels at 36-60 is abut 15 minutes
1 hour total for 3-4" blade
I start with a 60 grit on a bevel.

how many blades have you made or ground?

how are you grinding, what is your method?
I recommend how many ABS makers do it, work rest and push stick.
I don't think there is a more efficient way than this method. That's why they use it.

However your work looks nice (on IG), some guys really enjoy the process and love to labor over it, maybe that is you?

 

[Big Chris]

I also do a lot of post heat treat grinding.
On a full hard 10V blade of normal thickness I probably have around 20 to 30 minutes of grinding before I get to my finishing grits.
I go slower and spend a bit more time at my finishing grits.

 

[Richard338]

As a beginner trying very different styles each time, I think I benefit hugely from doing two trial runs with cheap Lowes steel, right before starting the real one.
It removes a lot of the doubt and hesitation. Usually the grind on the cheap steel seems easier because I'm more relaxed.
After that a prehardened 6" dagger took about 40 mins before the higher grits.

 

[Stromberg Knives]

What type of grinder do you have?

It's a pretty standard type of grinder. Nothing spectacular, but they're very robust. It's all steel, with solid steel tool arms. They're fitted with VFD and 3 hp motors.

 

[Stromberg Knives]

the first sentence says grinding a drop point hunter, which has a tapered tang. i was not sure if that and profiling was included in your time. it did not mention bevels only. 36 grit just doing bevels maybe 15 minutes for me.

Yes, I see what you mean. Didn't know that a drop point hunter implicitly meant a tapered tang. You learn something every day.

Thank you.

 

[Kevin McGovern]

Drop point hunter- does not imply tapered Tang. Someone had asked about Tang taper and I think he attributed that to your original post

 

[Stromberg Knives]

Hmm, I went out to the workshop doing for more hard labor. I managed to take the blade up to a A100 trizact finish (about 180-220 grit) and tried some hand sanding (haven't done that before with the Niolox).

Goddammit! It obvious that I during the heat treat managed to convert my Niolox to Adamantium.

The 240 grit Rhynowet Redline just slides over the blade without scratching it. No matter how hard I press, there is hardly a scratch.

I've solely used O1 until now, which hand sands very nicely. And I really enjoy the process, but this is just frustrating. Haha! I should add that my O1 blades are in 62-63 HRC range and my Niolox is in 60-61 HRC range.

And thank you all for sharing your thoughts on this. My lessons learnt so far:

1. Step my grind line up gradually when grinding and avoid a large flat spot.
2. Try the method with a push stick on workrest.
3. Stay the hell away from abrasive resistant (immune?) steels.

I'm very happy with O1 as my primary high carbon steel, but I'm looking for a stainless steel for my kitchen knives. I thought Niolox would be a good option, but with these results (image the belt cost in the long run!) I think I'll do some testing with other stainless steels.

What do you guys think of N690, 12C27M or 14C28N?