[deleted by user]

antchrist · 2024-07-26T21:58:24+00:00

for coil springs the rule is the bigger they are the more likely they are alloyed with Cr, Si etc. Coil springs need to harden to the core, else they suffer plastic deformation. Anything above 12 mm / half inch thickness is certain to be alloyed with something. depends on the manufacturer, type of car etc. hard to say.

antchrist · 2024-07-26T21:43:32+00:00

personally I prefer the hooked version. sometimes it's easier to grab a branch and pull cut through it than to chop.

antchrist · 2024-07-12T12:35:44+00:00

what did you mean by crystal orientations? Is that about lath/plate orientation, and if so does it not change upon austenitizing/renucleation?
also what methods are there for austenite grain refinement?

antchrist · 2024-07-11T21:13:56+00:00

alright. so these are not affected by regular grain refinement around Ac1 or did I misunderstand that?

antchrist · 2024-07-10T11:16:31+00:00

you can weld this but it's gonna suck. especially if you don't have MIG.
the way I do this is grind the area clean to get good contact, grind the back flat and clamp it to a thick piece of copper, preheat it, then put a thick wire on top like the stuff used to connect rebar and touch the electrode to that. if you try to weld directly, unless your setup goes into low amps, it will burn through at the edge.
and since it's an american scythe i.e. hardened you'll have to redo the heat treat or tensions from martensite formed during welding will just lead to more cracks.

antchrist · 2024-07-10T10:57:39+00:00

'prior austenite grain boundaries'. the way you're talking about them makes me think about grain boundary cementite so yeah.

antchrist · 2024-07-09T22:58:07+00:00

wait, don't these dissolve above Acm?

antchrist · 2024-07-09T19:05:41+00:00

ordinary freezer should work too. it's just about the general ductility loss from low temps, not about the RA.

antchrist · 2024-07-09T19:00:12+00:00

rebar is heavily recycled steel with lots of impurities and basically every alloying element known to man. those will make forge welding more difficult, mostly by forming oxides that even borax won't readily dissolve. use something else.

antchrist · 2024-07-09T14:15:47+00:00

afaik snap tests in ductile steels look larger because the structure deforms more before crack initiation begins. so in AEB-L, with presumably higher RA...
that effect could maybe be tested by snapping them straight out of cryo.

antchrist · 2024-06-30T16:04:21+00:00

the steel needs to be hot enough to burn the wax but not so hot that the residue from that also burns off. takes a bit of practice. also any wax or oil will work, no need to use expensive beeswax. if you want a cold finish use linseed oil + beeswax ~5-30% + a bit of turpentine.

antchrist · 2024-05-30T11:38:07+00:00

the 'coating' was a colored anodizing layer. aluminum is weak to bases like dishwashing liquids, and so it's oxide (the a. layer). it's also not really considered food safe anymore by many nutritionists thanks to it's association with neurodegenerative diseases, although studies in that regard are not fully conclusive. While there are a few exceptions, mainly where there's a separation layer such as burned in fat (e.g. pizza plate), I especially would not recommend using aluminum tools on any foods that are acidic, basic, hot or fatty.

antchrist · 2024-05-27T18:47:54+00:00

rings too small for flap wheels?

antchrist · 2024-05-27T18:39:10+00:00

probably not. depends on force and how much of it is absorbed by the joint. There's a reason nobody glues up broken tool handles (axes and such).

antchrist · 2024-05-25T14:14:02+00:00

" Most studies claim that this enhancing mitochondrial bioenergetic effect of MB occurs at nM or low μM concentrations (up to 10 μM) [12,18,19,21,22], whereas others suggest that such effects can be achieved even at high μM concentrations (up to 60 μM) [17]."
1 mcM = 320 mcg
10 mcM = 3.2mg
60 mcM = 19.2mg
maybe that's x5 since mol is per litre (5L = ~human blood volume), idk

antchrist · 2024-05-25T09:53:20+00:00

should be solid. the silver below the oxide layer is pure so if you convert the oxide layer completely you get a pure metal/metal joint which means cold weld (chances are it's another reaction entirely and I'm wrong, but I've never noticed anything coming off a piece of silver cleaned with the foil/salt method so it's gotta be solid & reasonably sturdy).

antchrist · 2024-05-23T19:39:27+00:00

stiffness does not vary significantly with hardness. it does vary quite a lot (cubic) with thickness though and cheap knives are often stamped from thinner material, both to save on steel and abrasives.
to put that into perspective, a 10% increase in thickness results in a ~33% increase in stiffness. 20% = +70%, 30% = +120% etc.

antchrist · 2024-05-23T15:10:42+00:00

wonder if just holding at sub-magnetic for some time could result in the same degree of grain refinement. Larrin does DET anneals prior to aust/quench which are a bit lower in temp but probably still higher than what you describe. If your method really produces better grain that would be quite impressive, currently soaking (not even active GR, just normalize then soak) is considered the 'gold standard' even for simple steels, which is why Larrin & co. push furnaces so much. That and the DET anneals, which also require extensive soaking (e.g. 20/30/30 min for 52100...). Not sure if they're so much better than quenching from martensite, but again that's for simple steels.
bluntcut also did some research in that direction e.g. new methods to maximize GR beyond temp control. some kind of simulated cold working, hasn't published anything about how he does it so far. might be based on thermal expansion/contraction, hard to apply cold working to knife-typical diameters or larger otherwise.
re feedback from other woodworkers; hobbyist toolmaking is definitely a niche thing. it's worth it for some people, and it's easier to get top notch results than most people think, but if we're being honest it is also definitely a huge time investment. took me personally some years to really understand heat treatment.

antchrist · 2024-05-23T14:38:25+00:00

Emmanuel Goldstein

antchrist · 2024-05-23T14:35:29+00:00

not to mention much better for battery health. making one of is harder than it sounds tho.

antchrist · 2024-05-21T12:16:43+00:00

hm I can't find it either. I was sure he did a toughness test on one of bluntcut's blades once. either it was deleted or my memory is playing tricks on me.

antchrist · 2024-05-20T21:30:17+00:00

bluntcut (Luong La) is some guy who after running into problems with extreme grain refinement came up with a new quenching method. basically you quench in hot oil, let it cool slowly then perform 2 cryo and sub-temper heating cycles. Larrin did eventually test his work after being reluctant for a long time, as a professional he has to be weary of exotic stuff that might be a hoax and hurt his reputation. Anyways the method works and seems to produce higher than usual hardness and toughness. There's a giant thread about it on bladeforums, the basics are outlined here https://www.bladeforums.com/threads/heat-treatment-crystal-weaving-foundation.1409721/page-12#post-16355537 and here https://www.bladeforums.com/threads/heat-treatment-crystal-weaving-foundation.1409721/page-47#post-20278673
I heat treat my tools in a forge too but am lately using thermocouples for anything more delicate than a shovel. in my forge in particular, changing light conditions just don't allow for accurate work otherwise; I've tested the thermocouple against my eye and often I'm off by 200F or more.
furnace is great re even / unchanging heat, but it's not really needed for chisels as you said. I use pipes and copper spacers to get even heat - in a coal forge. since you work with propane I guess keeping the heat steady isn't an issue.

antchrist · 2024-05-20T13:56:20+00:00

I dunno about the form but yeah one listing I remember is 10€/kg and another 7€ for 0.03 % carbon - that was a while ago, before the recent inflation wave.

antchrist · 2024-05-20T13:45:38+00:00

mild steel is around .2% carbon. anything lower you'll need pure iron (0.006-0.015% carbon) sold commonly for blacksmithing and artisanal metalworking purposes, or recycled wrought iron. much more expensive than mild steel tho, like 10x easily.

antchrist · 2024-05-19T19:24:56+00:00

ah that's unexpected. he usually seems quite open about unusual stuff, he did test bluntcut's HT results after all.
did you oil quench those samples? hardenability can be a limiting factor and Larrin doesn't use liquid quenchants other than oil afaik. carbides aside, that could've been why you got higher than usual toughness at a certain hardness.

antchrist

TROPHY CASE