Grinding bevels pre or post heat treat

Randydb said:
I have a respirator, hearing protection and face shield over my reading glasses when I grind.

I understand what distal taper is, but I am going to hold off doing that yet.
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glad to hear it! Start on your distal tapersas you grind these, a very slight pull towards you by the tang and twist in
Towards the top of the Platen is often all it takes, I also never pull the tip more than a 1/3th if the way across the Platen to keep from rounding the tip of the blade. StAy Safe & Have Fun!
 
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Randydb said:
Okay, I have never heard this before. I need to do more reading. Why is the ricasso the foundation?
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In any type of metal or woodworking you need to start with a "Reference" point that will remain constant. If the reference point changes the first measurement will be wonky and any subsequent work will be wonky. A true 90 degree spine and flat ricasso are your Main reference points to lay out your design.
 
Busto said:
In any type of metal or woodworking you need to start with a "Reference" point that will remain constant. If the reference point changes the first measurement will be wonky and any subsequent work will be wonky. A true 90 degree spine and flat ricasso are your Main reference points to lay out your design.
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Okay....I get it. I know the spine on one of the blades isn't square....my tool rest wasn't tightened up and moved a bit. I didn't notice until I was onto a second blade. I will go back and square up those edges.

I will do a couple searches and look at how to get my ricasso flat and finished.
 
Randydb said:
Okay....I get it. I know the spine on one of the blades isn't square....my tool rest wasn't tightened up and moved a bit. I didn't notice until I was onto a second blade. I will go back and square up those edges.

I will do a couple searches and look at how to get my ricasso flat and finished.
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If you have not checked out the Custom and Handmade section of the forums you should look through the Stickies there for the WIPS because there you will find a lot of information on what other Blade Makers are doing with lots of photos....Here is a link to Will Morrison's Stock Removal Bowie...pay close attention how he uses the Ricasso for marking purposes. Check out Post #29 in that thread it's on page 2, but it illustrates the reason for square and flat ricasso.

https://www.bladeforums.com/threads/introduction-and-a-wip.1082411/
 
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Busto said:
If you have not checked out the Custom and Handmade section of the forums you should look through the Stickies there for the WIPS because there you will find a lot of information on what other Blade Makers are doing with lots of photos....Here is a link to Will Morrison's Stock Removal Bowie...pay close attention how he uses the Ricasso for marking purposes. Check out Post #29 in that thread it's on page 2, but it illustrates the reason for square and flat ricasso.

https://www.bladeforums.com/threads/introduction-and-a-wip.1082411/
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That link was super informative. Thanks.

I never really paid attention to what people use to scribe guide lines on the spine/edges. I remember seeing some "home made" scribe jigs. I just used a drill bit that was 1/8 and laid it on a flat slab with the blank. Any advice? Should I buy one or is the drill bit method good enough?
 
Randydb said:
That link was super informative. Thanks.

I never really paid attention to what people use to scribe guide lines on the spine/edges. I remember seeing some "home made" scribe jigs. I just used a drill bit that was 1/8 and laid it on a flat slab with the blank. Any advice? Should I buy one or is the drill bit method good enough?
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The tool he used is a Toolmakers Surface Gage...the other tool used often is a Height Gage...If you were to buy anything the Height Gage is easiest to use with a Dial Indicator and the FOOT is generally Carbide tipped. You can also use Calipers but the tips on the calipers wear down and eventually become non serviceable for scribing lines, but its the least expensive alternative and just above the old Drill Bit method.
 
Okay, these bevels have been done with 60 grit to 5degree angle now. The thickness at the blade edge is 0.7mm. The two bevels are very very close in size to each other. I think I held the camera at a slightly different angle when I took the pictures and they don't appear so even here. But they are quite even when I measure.

Do I do a few passes of 120 grit now? Should I be going to 4 degrees or is this good? I'm not sure how far up the grits I should go before ready for heat treat. I know I still need to drill holes.

Some cool things I learned. Elbows into my sides, get bubble lined up gently near belt, lean in and sort of rock/lean body across and things usually stay pretty good.
Get off it when things go wonky. Had a few passes where I would start to chase the bubble but was going in the wrong directions and it all went whacky fast when that happened. Eventually I just stopped a pass when this would happen and start over again and it seemed to clean up the screwy pass before it.
This was fun! I have had to sneak 20 minutes at a time into the garage because we are getting ready for my daughter's wedding on Saturday so I have a lot of stuff I am REALLY supposed to be doing.

IMG_1400.jpg IMG_1399.jpg
 
Looks Good...I would take up to 400 grit...heat treat...drop back to 220 for a couple passes 320-400 and finish at 600.
 
Looks good.

Just a note, you should already have your handle holes drilled.

Grinding the bevel before the tang holes can lead to an accident if it helicopters when drilling.
 
Ahhh...didn't think of the possibility of helicopter with a close to finished knife. I had a thin piece of steel helicopter years ago and mostly cut the wire going up to the drill press. At least it shut the press off for me.

Take it up to 400 grit...does this mean 120, 220, 400? Or do I need something between the 220 and 400?

I must say, this first try turned out so much better than I expected so far.
Thanks,
 
Randydb said:
Take it up to 400 grit...does this mean 120, 220, 400? Or do I need something between the 220 and 400?
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That will work fine because after heat treat you want to drop back a couple grit sizes to clean up any lingering deep scratch pattern.
 
Randydb said:
Okay, these bevels have been done with 60 grit to 5degree angle now. The thickness at the blade edge is 0.7mm. The two bevels are very very close in size to each other. I think I held the camera at a slightly different angle when I took the pictures and they don't appear so even here. But they are quite even when I measure.

Do I do a few passes of 120 grit now? Should I be going to 4 degrees or is this good? I'm not sure how far up the grits I should go before ready for heat treat. I know I still need to drill holes.

Some cool things I learned. Elbows into my sides, get bubble lined up gently near belt, lean in and sort of rock/lean body across and things usually stay pretty good.
Get off it when things go wonky. Had a few passes where I would start to chase the bubble but was going in the wrong directions and it all went whacky fast when that happened. Eventually I just stopped a pass when this would happen and start over again and it seemed to clean up the screwy pass before it.
This was fun! I have had to sneak 20 minutes at a time into the garage because we are getting ready for my daughter's wedding on Saturday so I have a lot of stuff I am REALLY supposed to be doing.

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Taking shape. You stop when the height is where you want it to be. Finishing all surfaces of the blade before heat treat, to a grit of 220 or 320 is a matter of choice. Each making makes their own call. You will do finish grinding and sanding [after] heat treating is completed. Look up information on the different steels you are using; each one has different parameters on how thin the edge can be at heat treat and still come out straight, without a wrinkled edge. Trade offs. Finishing the ricasso before heat treat is a given; most makers take it to 400 or 600. There should be very slight sanding in this area after the heat treatment is complete.
I am sure you have found as you grind, there is much to making knives and grinding great bevels.
A confidence booster when using a Bubble Jig is to hook the tip of the clamp against the edge of the platen, center the bubble, all while not contacting the belt. Hold this position with the grinder running the belt moving underneath but not touching the steel. When you are steady, then lower the blade to the belt and make the pass applying pressure.
When you have some time at grinding, the passes you make will be made with much greater pressure on the blade blank. Fewer passes with fewer mistakes.

Regards, Fred
 
The basic rule of thumb for how thin and edge needs to be is “how violent is the quench?” If it’s a water quench or fast oil steel like 1095, w1, W2, the edge should be thick(er). Like 0.030”+. If it’s a medium speed oil, you can get away with a thinner edge, like 0.020” or so. (Generally speaking, err on the side of caution, ie make the edge slightly thicker than those numbers). If it’s an air/plate quench steel, you can take them to final dimensions for most knives, like 0.010”. Peters HT has done an excellent job on SUPER thin edges I’ve sent to them in CPMM4 and AEBL. Those were SUB 0.010”, even though they ask for 0.015”+ on air/plate quench steels.

And as far as the blade finish prior to HT...if it’s an oil quench steel that needs a thick edge, no reason to go any finer than 80 or 120 grit (scratch pattern tip to tang). Youre going to be removing more steel post HT to get to a thinner edge anyway...no need to take it any finer. But because an air/plate quench steel can be taken to final edge dimensions, you can polish the blade all the way up to your final grit prior to HT. If you want an 800 grit finish, go ahead and do that work while the steel is annealed and easier to abrade. After HT it’s a simple matter of polishing the oxides away with 800 grit paper (or whatever your final grit is).

This is just a general guideline, and assuming good scale/decarb protection during HT of air/plate quench steels. (And no distortion issues that might need to be ground out).

(Side note....if you’ve ever worked with steels like CPMM4, you’ll do yourself a BIG favor by taking it to final dimensions/polish prior to HT. Even at an 800 grit pre Ht polish, it’s not easy removing the post HT oxides with 800 grit!).
 
Now I get what you mean about setting the ricasso. I need to grind everything close in grit.

Grit question. I see a number of people start with 36 grit, others 60 grit when grinding bevels. Just a personal preference thing? Things don't go bad as fast? But the grinding takes longer starting with 60 grit?

I must say, if I don't rush the bubble jig is pretty fool proof. Once I get a bit of a grind started I can feel the flat that I have already created and it gets even easier. If I make my grind lines the same the edge stays in the middle of the steel.

I have 3 blades that are W2- so I want to leave edge 0.030 (0.7mm) thick.

The other 5 are S35vn - and post #2 AVigil says I can take it close to finish dimensions and seems to indicate it is air/plate quenched.

When I drilled the holes in the handle I notice the two steels drill differently. The S35vn mostly had small chips of steel come off and it "complained" a lot and wanted to bind as the bit came out the back of the steel. W2 got a lot of long strings of steel coming off as I drilled. I plan to grind the rest of my bevels today and I expect that they will feel different as I grind.
 
Maelstrom78 said:
Drill those holes!
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I did. But another question about that. I see people drill their holes for pins but drill a bunch of other holes, or else a bunch of partial holes. I assume this is for weight and for better glue hold on the scales? Small knives don't need extra holes? Just a personal preference thing?
 
Randydb said:
The other 5 are S35vn - and post #2 AVigil says I can take it close to finish dimensions and seems to indicate it is air/plate quenched.
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Adam is correct all the way....With Stainless like S35Vn save yourself additional post heat treat grinding by doing it pre heat treat.

Stainless like S35Vn definitely drills different than Carbon like the W2...Due to the Higher Alloy Content of Chromium. Not to be to concerned it's just the nature of the material....Bone Handle material drills differently than G10 they are what they are. If the Steel is complaining try using some form of Lubricant I prefer Boelube which comes in a Stick Form and doesn't leave an oily mess behind.
 
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