More Drilling AEB-L Post HT

C

Cushing H.

Joined
Jun 3, 2019
Messages
2,714
Man, this stuff is tough. making my way through drilling 1/8 holes for bolster .... using carbide tipped bits, drill press on slowest possible speed, everything backed with aluminum and securely clamped. Broke one drill bit as it broke though the back of the blade, second hole the bit has made it most of the way though, then stopped cutting (bit got dull???). Need to buy more (these ones at home depot ... but looks like they can be had at amazon for ~$1 apiece ... so will lay in a supply).

That said, I think I will do my utmost to NOT drill post HT, and get the holes drilled pre HT ... unless JT complains over risks of warping in HT, as he will undoubtedly be doing that piece of the work!!! :-)
 
Try solid Carbide and a drop of Cool Tool. There is a sweet spot with pressure . Take your time. Stay safe & have fun!
 
Depending on the blade, you may be able to soften the bolster and handle area with a torch and not do any damage to the temper of the edge. Drilling pre-HT shouldn't cause any problems, I do it all the time.
 
Cushing H. said:
Man, this stuff is tough. making my way through drilling 1/8 holes for bolster .... using carbide tipped bits, drill press on slowest possible speed, everything backed with aluminum and securely clamped. Broke one drill bit as it broke though the back of the blade, second hole the bit has made it most of the way though, then stopped cutting (bit got dull???). Need to buy more (these ones at home depot ... but looks like they can be had at amazon for ~$1 apiece ... so will lay in a supply).

That said, I think I will do my utmost to NOT drill post HT, and get the holes drilled pre HT ... unless JT complains over risks of warping in HT, as he will undoubtedly be doing that piece of the work!!! :)
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If you can spend more then one dollar you can try this one.............Idrill about fifty holes with 4mm bits so far ...most over 67 HRC HSS steel
https://www.bladeforums.com/threads/drilling-hardened-steel-easy-cheap-way.1625415/
If you want to go really cheap sharpen masonry drill bits ....................
https://www.bladeforums.com/threads/sharpening-masonry-drills.1540592/
 
AVigil said:
You drill post heat treat on purpose?:eek:
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This came up on an earlier thread I posted:
https://www.bladeforums.com/threads...ling-in-hardened-steel.1671044/#post-19113748

Many here said they purposefully wait to drill AEBL (and other steels) until after HT due to warping issues if done before. Per Stacy, this is best done with a mill (I dont have one), but can be done on a drill press with appropriate precautions (speed, carbide bits, clamp the daylights out of it, back it with a metal backer). Most say "be prepared to go through multiple bits. right they are. Not my purposeful choice (JT says he has AEBL HT down ... I will take him at his word :) ), but occasionally I have changed my mind on design, and needed a hole or two after the fact - as in the current case where I had intended to solder a bolster (no pins), and am now changing my mind and plan to JB Weld/Mosaic pin the bolster. Previously tried this on 15N20 ... worked reasonably well. AEBL works, but, at least so far, is "hungrier" for bits :) . I expect that this stuff is as tough in service as it is in making :)
 
Carterwhopkins said:
Depending on the blade, you may be able to soften the bolster and handle area with a torch and not do any damage to the temper of the edge. Drilling pre-HT shouldn't cause any problems, I do it all the time.
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Thanks Carter. I should be able to get though this blade without resorting to annealing the handle - though at the cost of more masonry bits. Mostly I just wanted to vet that "man ... this stuff is tough!!!!! :-)
 
Rhinoknives1 said:
Try solid Carbide and a drop of Cool Tool. There is a sweet spot with pressure . Take your time. Stay safe & have fun!
Click to expand...
Definitely I am finding that "sweet spot" - too little pressure and ... nothing but heat. Too much and the drill bit bends and (presumably) breaks. Interesting balance to watch unfold ;-)

Natlek said:
If you can spend more then one dollar you can try this one.............
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Thanks Natlek I will see if I can buy these here in the states. From the outside all these carbide tipped bits look the same - what I dont know if there is a difference in quality either in the carbide used, or the strength of bond to the shaft of the drill bit. Need to experiment more i guess :-)
 
Cushing H. said:
Definitely I am finding that "sweet spot" - too little pressure and ... nothing but heat. Too much and the drill bit bends and (presumably) breaks. Interesting balance to watch unfold ;-)


Thanks Natlek I will see if I can buy these here in the states. From the outside all these carbide tipped bits look the same - what I dont know if there is a difference in quality either in the carbide used, or the strength of bond to the shaft of the drill bit. Need to experiment more i guess :)
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Drill a small divot with a smaller size Carbide bit to get started.......I’ve found solid Carbide to work far better , it seems those Tipped one are Masonry bits. I nose around on EBay to find solids..
 
Rhinoknives1 said:
Drill a small divot with a smaller size Carbide bit to get started.......I’ve found solid Carbide to work far better , it seems those Tipped one are Masonry bits. I nose around on EBay to find solids..
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Thanks. Starting the hole is definitely the most “random” part. So far i have been using light pressure to minimize walking of the bit. If a smaller all carbide bit allows more precision, inam all-in. :-)
 
Cushing H. said:
Thanks. Starting the hole is definitely the most “random” part. So far i have been using light pressure to minimize walking of the bit. If a smaller all carbide bit allows more precision, inam all-in. :)
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Not all the way through, more like a deep Center Punch divot to get you started!
 
Rhinoknives1 said:
Not all the way through, more like a deep Center Punch divot to get you started!
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Lol x2. I, probably stupidly, actually tried using a center punch to try to create a divot. All i ended up with was a flat center punch and a totally unblemished piece of aebl. :). I actually laughed and told myself i should have known better. Your idea to create at least some small divot with a small short all carbide bit is really useful!
 
Hmmmm, I missed that thread.

I have made many many blades with AEB-L and would never dream not to pre drill my holes.

I have seen hundreds of AEBL blades heat treated at TruGrit with holes pre drilled.

I will never ever plan to drill holes in any knife after heat treatment
 
Only Hundreds? ——————————-Observe, Modify & over come!———- Mine were never planned, that’s drilling after HT! I’ve had to do it on a few blades over the years, The holes I wanted pre cut by water Jet needed enlarging for my Loveless Bolts, after HT/Cyro , I needed to move the Lanyard at a customers request, etc etc etc! Life is what happens while you are making other plans!:D LOL
 
No water jet for me.

Sure it may have to be done do to unforeseen circumstances, but not drilling holes pre heat treat do to warpage is just something I never heard of due to it not actually needed.
 
I too drill all my holes pre ht in AEB_L, 26C3, A2, damascus or anything else thats gonna end up a knife. But as Laurence says life happens. Had to drill two holes in AEB-L at 63 RC for a roundknife that the customer wanted a bolster on and neither blade already back from ht had bolster holes. So it was either make the customer wait several months or drill a couple holes and he could be in the next batch and is. Bolster will go on today. Used an old broken solid 1/4" carbide that I had resharpened to start a divot and then three Bosch ($1.70 ea) from the Depot 1/8 inch masonry bits. Got er done but was first time in years that I had to. Because those carbide masonry bits wobble a bit they actually make a #30 size hole not a 1/8th which is perfect, the 1/8' pins slide through easily.
 
AVigil said:
No water jet for me.

Sure it may have to be done do to unforeseen circumstances, but not drilling holes pre heat treat do to warpage is just something I never heard of due to it not actually needed.
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We learn here that hole in steel are stress riser :) For me , it is more safely /carbide drill bits not make blade to become helicopter / and easy to drill hole after HT .....
 
solid carbide will make the hole
a side note You can Drill a hole using any size Rod and Valve grinding compound...
the grinding compound is used as a abrasive to chew through the blade (and makes nice holes)
a drop of water a touch of grinding compound and go ... when it acts like it is not cutting anymore add a little more compound,
very messy but works..
 
Natlek said:
We learn here that hole in steel are stress riser :) For me , it is more safely /carbide drill bits not make blade to become helicopter / and easy to drill hole after HT .....
Click to expand...

Did they teach you to counter sink the holes to remove the 90 degree angle to keep it from being a stress riser?
 
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