Cermarking heat treated parts

[Scott Shepherd]

Anyone do much Cermarking on heat treated parts? More and more work is coming in that has been heat treated. I've had mixed results, depending on how hard it's been heat treated to. If it's on the lower end of the Rc scale, I can get decent marks, but head into the Rc60's and it's working less and less, which is what I would expect. One customer makes their own knives and they wanted an image that didn't stand out, but was subtle, which is what we got because it was so hard.

Any tips for doing harder parts with Cermark? Just slow it down to super slow mode and roll on? On the knife blades (they are survival type knives and he makes them really hard), I've slowed it down to 4% speed, 100% power, 1000dpi, and it doesn't get any darker than running it at 20% speed, 100% power.

[Robert Walters]

Is it possible for them to heat treat AFTER they've been marked?

Have you thought about pre-heating the knives/blades (if possible)?
I'm thinking heat, thermal expansion, opening the grain in the metal (somewhat).

[Scott Shepherd]

Is it possible for them to heat treat AFTER they've been marked?

Have you thought about pre-heating the knives/blades (if possible)?
I'm thinking heat, thermal expansion, opening the grain in the metal (somewhat).

Unfortunately I don't have any control over the process. People bring me things already done. I'm guessing the heat treating would ruin the cermark, but that's just my gut feeling for how how it gets when they heat treat it. Some of it's oil hardened, some air hardened.

Other parts are precision parts, made, heat treated, and ground. I'm the last step. Just finished 120 of those, marked in 3 places each, with 120 more coming tomorrow. Those marked pretty well, but I'm guessing they are in the Rc40 range, not nearly as hard as those knives.

[Robert Walters]

What if you just pre-heat the parts, maybe to 150F, then laser?
It might be just enough TE to let the cermark penetrate a tad better.

Heck even sitting in a summer sun would get that hot, if not more.

[Kev Williams]

Try closing up the focus...

On my Triumph, the more in focus it is, the grayer the cermark goes. Very nice mark, very consistent, permanent, but gray. If I really add the power it takes on a bronze tint.

I have over a dozen focus 'stubs' I've made out of 1/4" thick Cintra in various lengths. For Anodized I'm at 1.485" from the edge of the lens barrel. To do Cermark, I'm at 1.38", a .105" drop, which is substantial, but this is where I get Cermark to go black. I lose some very small high detail, but not much.

If you have a 3" lens, you might try that too...

And finally, sometimes less is more- since I get gray due to what I assume is too much power, maybe you need to back off the power rather than add it?

[Scott Shepherd]

Kev, are you getting black marks on really hard items, like in the 60 Rc area?

Robert, I might try preheating a knife. I'm trying to convince him to let me sandblast his logo into it rather than cermark it. He keeps saying he wants to try it and then never brings me one to try it on.

[Robert Walters]

He keeps saying he wants to try it and then never brings me one to try it on.

Famous last words... don't ya hate that! lol

[Dave Sheldrake]

Cermark is an ionic bond so any change to the structure of the metal by heat treatment will change the bond properties Scotty.

cheers

Dave

[Glen Monaghan]

Why so hard on a survival type knife? I wouldn't want one like that... Sure, the harder the edge, the longer it stays sharp (like those infomercials that cut tin cans with a knife and claim you never sharpen them... that's because they are so hard you can't practically sharpen them!). But, the down side is that it is also harder to resharpen the blade, and resharpening becomes essentially impossible in any reasonable scenario without diamond stones. Also, the harder the blade is, the more likely it is to chip or break if you baton it or lever it, which is really bad for a blade you are supposedly staking your life on. You just need to educate him on the need for a lower hardness number, both for you and his customers ;^)

[Mike Null]

Steve

I've had durability issues with Cermark on knives in the 58-62 range on the c scale. Since these are my own I'm going to try to mark them without Cermark. I've done some marking in that manner before and was fairly well satisfied with the result, but it is slow.

For what it's worth the manufacturer's mark is also very faint. We hand wash only as these are quite expensive knives.

[Scott Shepherd]

Why so hard on a survival type knife? I wouldn't want one like that... Sure, the harder the edge, the longer it stays sharp (like those infomercials that cut tin cans with a knife and claim you never sharpen them... that's because they are so hard you can't practically sharpen them!). But, the down side is that it is also harder to resharpen the blade, and resharpening becomes essentially impossible in any reasonable scenario without diamond stones. Also, the harder the blade is, the more likely it is to chip or break if you baton it or lever it, which is really bad for a blade you are supposedly staking your life on. You just need to educate him on the need for a lower hardness number, both for you and his customers ;^)

I don't know, I don't question him. He sells a lot of these handmade knives and they get awesome reviews. He uses them and abuses them pretty hard. He's not just a survival knife maker, he's a survivalist himself, so he uses the tools he makes extensively and who am I to tell him what to do? I do know they are hard.

Thanks Mike, I'll try it without the cermark next time.

Dave, you really need to dumb things down when talking to me :) Ionic? :) That's a new one for me. I'll have to google it ;)

[Kev Williams]

Steve (or Scott, or Festus ;) )

-- I haven't done much if any hardened SS with a laser. Whenever someone brings me hardened stuff they always want it tool engraved (and what fun that is)...

My nephew had me laser etch some SS parts once that went thru heat treat and the Cermark discolored badly...

[Robert Walters]

Dave, you really need to dumb things down when talking to me :) Ionic? :) That's a new one for me. I'll have to google it ;)


Scott,

Yeah, I thought Dave had been watching one too many infomercials...
"Cook-o-matic makes cooking a breeze with it's state of the art ionic bonding technology"
<audiance_ooh_ahhhs>

BUT WAIT, THERE'S MORE!

If you don't mind (no worries either way)...
PM me the link to the knife guy's website, I'm always on the lookout for a good knife.

I googled it, no mention of Ron Popeil either...
http://en.wikipedia.org/wiki/Ionic_bonding

[Scott Shepherd]

Hi Robert, he doesn't have a website. He's a word of mouth guy from survival type people. He's always bringing me something new, telling me "this is the hottest new knife material out there", and he'll name the material and I've almost never heard of it. When he mentions tool steels, I usually know them, O1, A6, D2, things like that, but he's talking things I've not heard of. He makes some great looking stuff. It all looks wore out when it's brand new, that's his thing. So there's no chrome or polished pieces. You can see grind marks on the blade where he made it. It looks like it's about 20 years old when it's new. People seem to love them. He was selling so many, I think he doubled his prices and he still can't keep up (it's a part time job for him).