Thanks for watching

Unlikely. In broad terms and with quite some simplistic generalizing, 1 Most instructors are journeypersons, who end up teaching. They are not teachers. Neither are they engineers, metallurgists or chemists. They never upgrade with college courses either, most colleges don`t pay for such upgrades for staff. They want to run the business with minimal spending. 2 Metal fabricators calculate and fab stuff out of 1 type of steel - or so. Their curriculum does not cover anything covered in my video. Instruction about metals is limited to a "Do this, this will work." approach. 3 Your instructors are likely to be seasoned pros who are in fact excellent Metal Fabricators. Enjoy math, have fun throwing some sparks, discover and learn beyond the textbook minimum. Thanks for watching.

Welding gear review from class: kzfaq.info/get/bejne/f9OieaSe36yZfqc.html

Glad you enjoyed it!

Thanks for watching!

Glad you liked it!

Glad you enjoyed it!

+Harold Westrich And me..

Thanks for the feedback. I very often indirectly refer back to this video or use terminology from it. For a recent example, check out: kzfaq.info/get/bejne/htGEaJmQvt3Do58.html

Thanks for watching

Nice, tell us how they last and sharpen when you get to it. Thanks for watching!

Thanks for watching. Here is my playlist of related videos kzfaq.info/sun/PL9cPDQOOfTepp8sSTY7xoGsAmX5MUf-aS There is also a weldability spin on types of steels, kzfaq.info/get/bejne/kLOXgbxezbHUZqM.html and another playlist on steel and material failure kzfaq.info/sun/PLtsCbF7YOOwjLGSfkPQGBxoFkVyFNUotZ

Thanks for watching & feedback.

No problem, what is it that you do. You seem pretty knowledgeable about metals, yet you do a lot with bikes to. Just wondering?

Thanks for watching, I have other steel titles as well, just type "steel" into the channel`s search bar.

+Dunk O Idea: Shoot some video at that foundry, upload and link it with this. Thanks for watching.

Ninz306 Thanks for watching!

Thanks for watching

+Idomake Thanks for watching. These videos were shot on-the-spot to replace the expanded set-up in class. Definitely not HD, not anything, just holding camera with one hand while trying to work with the other ... If you know anybody sponsoring educational development, send them this way.

Sure do. What kind of knife? Scalpels get thin and superhard, bushwacking knife gets chubby and impact resistant.

Oooookaaay. Usual work flow is: find steel chunk, heat treat, draw knife design out, cut out shape, heat treat again, fit handle. I recommend a generic knife heat treatment sequence from Bob Loveless`s book Knifemaking p.57, 66: 1 Annealing Heat thoroughly to at least 1400 F (760 C) or past the Curie point, then let cool slowly in vermiculite or in an oven over a 12-hr period, not faster. After the grind, bevel and taper are done, 2 Heat up to same high temperature, quench in a barrel of cold oil, brine or water, clean blade, temper at 350 F (177 C) for 2 hours, then let cool in air to room temperature on its own. (No fans) It will be hard enough to hold a fine edge and not too brittle.

***** Thanks for the feedback and watching. Questions, ideas? Let me know.

It might make for an Informative video if you could do lecture on nut and screw threads, just a thought.

+wakefieldyorkshire I`ve got this: kzfaq.info/get/bejne/nNWma9GB37WtZoE.html on another channel. Keep digging around, some are more geometric, some are more calculation focused, such as this:kzfaq.info/get/bejne/gp9pn9Fy1ryvYXU.html

Thanks for watching!

Thanks, there is more on kzfaq.info

Awesome, thank you!

Thanks for watching!

Ivan Levels of hardness is produced by either (1) "cold work" - forming, bending, extruding, ... (2) "alloying" - carburizing, nitriding, high carbon steel, alloy steels, tool steels ... (3) "heat treatment" - quench & temper, anneal, Mild steel is weldable, anything alloyed (Carbon or anything) is tricky or impossible Some ideas are embedded here: kzfaq.info/get/bejne/bd15rLaYvq67ZGg.html or here kzfaq.info/get/bejne/r95xl8iQ0M6UfHk.html or here kzfaq.info/get/bejne/aZ-Rm9OUy72zdYE.html Just type in keywords "brittle" or "ductile" on my channel, see what comes up. I guess I can make a comprehensive video on what I just typed up, too. I`ll think up some visuals for it. Thanks for watching.

theoverengineer You're awesome! Thanks for the info!! You were a big help!

Ivan bitte schön

theoverengineer spasibo

Sure, thanks for the idea. Will send as link.

Never worked with speakers, no clue whatsoever. Thanks for watching, though!

+Rudy Cambara Chemistry-wise 0.55% carbon is in the steel which makes it hardenable by heat treatment (power sharpening can destroy it), has some give and not super brittle. Will rust right away unless protected. It was probably cheaply cast in a mold with no sign of going through upset forging. Physics-wise a katana`s making, center of gravity and weight distribution are just us important.

+theoverengineer Thank you for responding so quickly!

Kanagaraj Subramanian Plain carbon steel = low carbon + medium c + high c groups, mild steel = higher end of low carbon nut not as high as medium carbon steel. In North American standards by SAE/AISI (differents from British, Japanese or German standards) the carbon content in low c = 0.05% - 0.3%, mild steel = 0.15% - 0.3%, medium c = 0.3 - 0.6%, high carbon = 0.6 - 0.9%. By definition steel can contain 2.1% carbon, but it does not make a practical difference if a steel is 1.3% c or 2.05%, so nobody makes steel over 1% C. All % is by weight. What steel designation numbers mean (1080, 4150) kzfaq.info/sun/PLtsCbF7YOOwjLGSfkPQGBxoFkVyFNUotZ

thx

During quenching the microstructure of steel changes. In quenching, red-hot steel`s microstructure called "austenite" turns into "martensite', regardless of the quenching medium. (Brine can also be used). Martensite is extremely hard and brittle. Water cools faster, oil cools a bit slower. In water quienching, more of the austenite forms martensite, and less of it forms pearlite - a softer form of steel. In oil cooling more pearlite forms and less martensite, so the finished steel is more ductile, less brittle. Welding changes the microstructure of steel around the weld, all martensite and pearlite will transition into "ferrite" a very soft and weak form of steel (nails, rebar, roof flashing). In addition, all the fine dissolved carbon runs and clumps together and solidifies into streaks and layers of graphite (same stuff in pencils). It just breaks right there, graphite has zero strength. Even if the weld is quenched somehow to form martensite, graphite layers will still form, it is not reversible and be a weak layer in the weld area. So: it can be welded, it just won`t hold. Like trying to weld the claw back on a hammer, pretty until you pull a nail and breaks 10 seconds into it.

i have herd oil quenching ads carbon to the metal this also makes it harder

NOBOX7 Laying steel in a charcoal bed for 4-10hrs will add a quarter of a single percent of carbon to the steel, to a depth of 5 -10 microinches, a 45sec oil quench does nothing. Added carbon only makes the steel harder at the depth of the added carbon, microscopic amount of surface hardening. Done on gear teeth and shafts commonly.

Axe head : Most durable materials: 316 stainless, a.k.a. 14-12 stainless, does not hold an edge Best edge retention material: tool steels, including high-speed steels, none of them are resistant to corrosion The edge has to withstand shock or impact loading without shattering and chipping. Medium carbon steel is a reasonable material, since having an edge is more important than resistance to corrosion. Axe needs to be made with forging, in a forging press under thousands of kg or lbs of pressure, at a forging temperature. Without the right method at the right temperature, an axe head could be shaped but won`t work as an axe. Just a decorative mantelpiece.

theoverengineer. So a simple blacksmithing forge to heat the metal and 2 lb hammer should suffice? With heat treatment and tempering of course

Give it a go, see how it turns out, chop some wood, shoot a video and tell us about it.

theoverengineer thank you for the advice. This is very helpful

Blade looks good on paper. Hope they use what they claim they do, hope they make it as it should. Here is how it looks like when they have a clue: kzfaq.info/get/bejne/ptaVlqd3xrLXl3k.html Types of stones don`t matter much, particle uniformity does, together with particle hardness, particly crystaline structure and behavior. Here is my take on sharpening: kzfaq.info/get/bejne/gt-kobiiveC4e3k.html

ok thank you for quick response and good advice :)

NOBOX7 Thanks for watching!

donny ward digit 3 means "austenitic" stainless group, and 04 is just sequential, the 4th mix. Non-magnetic, soft & formable, excellent corrosion resistance. Sinks, faucets, strainers, kitchen stuff with no edge.See chemical composition and a bit about properties here: kzfaq.info/get/bejne/Zsx7dKmq2J-WY2w.html

donny ward 304 refers to class of SS,as it mentioned in the video about types of SS-Austenite,martensite and duplex SS.Austenites have 200 and 300 class,so if you find anywhere with the label of 304,316 that's austenitic stainless steel..304 is also widely known as 18/8 stainless steel,18% chromium and 8% nickel basically and used for surgical items,the other 316 is 18/10 chromium being 18% and nickel 10%,its used in kitchen cutlery and sinks...i think 200 class stainless steels are less corrosion resistant as compared to 300 class....and yes Austenite SS also makeup a huge part of Pressure parts in Industrial boilers preferably for making superheaters and reheater tubes capable of withstanding high pressures and temperatures.so Austenite SS makes majority of the SS produced in the market,swiss knife like shown in the video is strong and tough,its made up of martensite..duplex has roughly twice the strength of Austenites.

Thank you for this information. I frequently weld 308 formed plate and 308 pipe. I noticed my fitter's magnet wouldn't work on SS. I've been curious what determines how magnetic SS is. I'm guessing it's the amount of chromium in the steel. Thanks again for taking the time to respond.

donny ward Not the chromium. Austenite. Austenite is a special crystal, atoms locked in it won`t be magnetized. Now envision a cube, with atoms sitting at the corners + 1 in the middle of the cube. Austenite has this body-centered cubic crystal lattice, ferritic and martensitic steels are magnetic & are face-centered cubic.

Hardening is basically a heat treating process, and can be applied to any type of steel, though some will get harder than others. But it is a different subject.

No, completely different steel numbering system. Its Carbon content is 0.12-0.18%, which is the mild steel range. EN36 is also alloyed with Ni and Cr which make the steel case hardening. EN36 is similar to SAE 3400-series Ni-Cr Alloy Steel. EN36 is suitable for roller and ball bearings of extra light section, aeroplane and motor crankshafts requiring hard surfaces for roller paths, connecting rods with case-hardened ends, as well as highly stressed gudgeon pins, gears and certain types of collets.

+Sahil Gupta I`m sure you can. It is also possible to paint steel. Needs proper surface prep: cleaning, pickling, priming, drying or possibly baking in a kiln between top coats, depending on paint type.

+Amra That`s right, it works exactly like that in carbon and alloy steels.

Thank you so much for the response! That is extremely helpful :)

Blade knife for what? Surgery? Bush whacking? Skinning deer? Chip carving? They all need completely different materials, completely different heat treatment, completely different blade geometry. I strarted a series on strength, durability, impact resistance, hardness and other things at: kzfaq.info/sun/PL9cPDQOOfTepp8sSTY7xoGsAmX5MUf-aS

is a Survival Knife Custom Made by a friend for Bushcraft and Outdoors , is a good Chopper aswel is made for heavy works ,out in the wilderness , chopping trees hunting , makeing shelter etc . Knife specs 7" blade(20cm) 3/16"( almost 5mm) thick. Steel is 80crv2 .he normalize the steel with 3 cycles. Do 1 heat treat and quench, and 3 cycles of tempering is that any good for it? thanks

Nicely made so far, will need to keep it dry but should last a long time, especially if the edge is ground on it properly.

ok nice to know that ,thank you :)

Adrian Wolf 440c stainless steel best for Knife. It's the strongest steel ever.

DaigenHyorinmaru Weakness is not a metallurgical term. Brittleness? Low tensile strength? Low toughness? Lacking hardness? Surface hardness? Lacking impact resistance? Inclusions? Porosity? Slag? Lack of fusion? Delamination? Lacking balance? Blade not flexible? Low elongation? Do specify. Might want to start with a metallurgical textbook from library.

DaigenHyorinmaru I recommend sword buyers guide. this is good info www.sword-buyers-guide.com/buy-swords-online.html

Good resource, thanks for sharing.

+theoverengineer ..... fusion?