Rockwell Hardness Test

Basic principle and practical procedure of the Rockwell hardness test
- Testing machine, test piece, conical diamond indenter
- Basic principle, hardness definition, testing procedure
Responsible for this video: Prof. Dr.-Ing. Rainer Schwab, Hochschule Karlsruhe (Karlsruhe University of Applied Sciences), Germany

[@Nitrxgen]

why does your guy walk backwards to the testing machine ?

[@Zephero]

He doesn't know how to walk forwards. He's been walking backwards for his whole life

[@mohawkcollege6123]

@@Zephero HAHAHAHAHA. I laughed so hard at this! Good one.

[@Zephero]

@@mohawkcollege6123 I'm glad I made someone laugh

[@Chillnel]

It is sort of like hyper awareness response to being watched/recorded. He's focused more on the peripheral vision and using other more physical senses to keep in co-ordination . How do i know ? I've done the same shit before. he's essentially keeping his front side, facing the things he's thinking of secondarily and keeping track of them, while relying on muscle memory and feel to perform the actions he takes.

[@WildChildDos]

Yep thnx,nice that u showed all 3 hardness testings in a clear explanation here on YT

[@jciupa]

Great videos, studying for second class power engineering. big help, makes it simple

[@philipphpunkt9481]

Sehr interessant. Von Rockwell-Härte habe ich schon oft gehört, aber das Testverfahren kannte ich noch nicht. Danke für die Demonstration!

[@MaterialsScience2000]

"Any new videos coming out soon?" We are working hard, 7 new videos are almost finished, hope to upload them in 2 or 3 months. Sorry, but we have to do all this besides our daily work.

[@Noeman2009]

Do you have a video about difference between hardened, tempered, annealed, normalized, heat treated steel?

[@MaterialsScience2000]

Answer to "Do you have a video about difference between hardened, tempered, annealed, normalized, heat treated steel?" Sorry, no. But I keep it in mind ...

[@esmealvarado5887]

great video! studying for my cwi and this helps !!!

[@hkchoi4364]

thank you for the awesome video!

[@Philcotigo]

I was looking fo the e variable on screen but only found an h in the lower left corner. Assuming this to be the e from the equation seems to be wrong. So where is e and what is h? If HRC is equal to (0.2-e)*500 and should result in 54.89 then e would be 0.09022mm but not the shown 0.922mm. Is there a digit missing (bad programming of the "Pruefprogramm Nr. 5") or is the assumption e = h wrong? If h would be e then (0,2-0,0922)*500 = 53,9 but not 54.89. The substraction of both equals to 2*10^-3. Is this the innitial indent depth or is there another equation explaining the delta?

[@MaterialsScience2000]

Answer to "I was looking for the e variable on screen but only found an h in the lower left corner. ..." Sorry, e is equal to h; we should have used the international e instead of h. Congratulations for your observations! The difference between the displayed and the calculated result is due to a calibration procedure. The indenter in our testing machine has been calibrated, using highly reliable specimens with accurately known hardness. Indenters, especially for HRC, are never perfect, and the calibration increases accuracy. Sorry for the late reply, I was extremely busy.

[@naota3k]

Fantastic.

[@MaterialsScience2000]

I am afraid I am hopeless: Instead of "international e instead of h" the correct answer is "international h instead of e". Sorry.

[@abdulghaffar2886]

plz tell that these HRB,HRV and HRV are used to determine compressive load

[@basikwon1]

Hello everyone, I had a question regarding Rockwell harness indenters. Hopefully someone can help me out. Ball indenters are classified as class a and class b. I recently ordered an indenter but received a class a indenter, can a class a indenter be used in lieu of a class b? Class b indenters are for everyday use and indirect verifications as class a are to be used for indirect verifications and standardizing test blocks. The company that we purchased from states that a class a can be used for everyday testing since it goes through more stringent QC. Any help would be greatly appreciated.thanks!

[@sammyblackchow9541]

I would ask the person(s) that I was performing the test for to give you the information needed. Talk to a certified testing lab.

[@sudenair22]

Please explain the intender and intendation size (width) difference in between HTC and HV. Please advice, that will be very helpful

[@MaterialsScience2000]

Answer to "Please explain the intender and intendation size (width) difference in between HTC and HV. Please advice, that will be very helpful" You probably mean "HRC" instead of "HTC". This is actually a long story. Main ideas are: The Vickers hardness measurement method is almost universal, giving the opportunity to measure with very low forces (extremely small indents) up to about 100 kp (981 N) (medium size indents). The Rockwell hardness measurement method is suitable for moderately hard to comparative hard materials. HV is difficult to automate (the diagonal of the indent has to be measured), HRC is easy to automate (the depth of indentation is easy to measure). In both cases the indenters are made of single crystal diamond; the lateral dimensions of the indenters are around up to 1 mm, so this is the maximum lateral indent size. The Rockwell hardness measurement method offers many variants, not only the described HRC method.

[@Buchunteli]

is HRC28 and HRC40 a good quality?

[@JustinThompson-yz8yz]

What if I need a very hard material? Is Rockwell Hardness C of 65 enough?

[@MaterialsScience2000]

Answer to "What if I need a very hard material? Is Rockwell Hardness C of 65 enough?": This depends very much on the application. 65 HRC is a relatively high hardness for steels (maximum about 70 HRC) and many tool steels have this hardness. However, there are much harder materials such as cemented carbides or ceramics. For very hard materials, HRC is not a suitable method and HV is measured instead.

[@ryansafour5479]

Haha wow, anti climax much! Waiting for something cool to happen.... 'Thats it!'... Did i miss something :p Thanks Uploader!

[@finnmurtons8727]

well all they did is find the hardness of the steel sample. they expect us to wear ppe whenever we use this tester but we really dont need it tbh. our rockwell tester is an older, manual version where you have to manually wind the wheel up until it displays around 100N then you put the weights on, wait 10s, then release

[@backyardmachinist]

The more we automate engineering and production, the more it will feel that way. CNC machining is the same. Its important to understand the processes happening though.

[@austinchew224]

How to convert HRB values into HRC values?

[@gaithsabah1026]

Thank you for helping:)

[@lewisrand9488]

the permenatnt depth that is measured by 'e' is tht from depth 1 to 3 or 1 to 2????

[@billdavies6463]

Watch video from 0.53, it states that the permanent deformation is from 1 to 2.

[@dalebrenke2238]

Question, how do we check hardness when the steel is much thinner, as in 28 ga sheet metal

[@MaterialsScience2000]

+Dale Brenke Answer to "Question, how do we check hardness when the steel is much thinner?" If the sample is too thin (in HRC testing less than 0.5 mm (hard material) and 1.6 mm (rel. soft material)) no reasonable test is possible. >> Use Vickers hardness test with low load instead.

[@talkstreats934]

how do i find the e for this?? what instrument can i use to measure this e

[@MaterialsScience2000]

Answer to "how do i find the e for this? what instrument can i use to measure this e?" The depth of indentation e is measured by a displacement transducer (a device that measures a distance / a path). This device is located inside the machine. ":

[@robtennant98]

does this test produce an indentation in the material then?

[@MaterialsScience2000]

Answer to "does this test produce an indentation in the material then?": Yes, testing typical materials there is always a permanent indentation. It is not much, in the case of HRC testing up to around 0.2 mm.

[@wyattbrule12688]

I am taking a CWI training course through the AWS. The learning module claims it is IMPERATIVE to prepare the test specimen's surface - I got the sense it should be borderline mirror finished or polished to get an accurate reading. Is this true? or what are the surface metrology requirements? Thank you

[@MaterialsScience2000]

Answer to: "I am taking a CWI training course through the AWS. The learning module claims it is IMPERATIVE to prepare the test specimen's surface - I got the sense it should be borderline mirror finished or polished to get an accurate reading. Is this true? or what are the surface metrology requirements? Thank you" The idea of the preliminary (or minor) load in the Rockwell hardness test is twofold: (i) to press the test piece in a defined way onto the support table and (ii) to create a small preliminary indent. This preliminary indent makes the test result independent of the influence a moderate surface roughness. So for the HRC test the specimen's surface does not need a special preparation, as long as the surface is not too rough. In contrast, a polished specimen surface is required for the Vickers hardness test at very small test forces and very small indents.

[@maulikruparel7831]

Thanks from Gujarat, India!

[@ManufacturingET]

Thanks!!

[@MrAghosto]

Nice Video.. Thanks a lot

[@pnb3876]

Does the tester have to walk backwards?!?!

[@vejet]

+MaterialsScience2000 Is one test seen as being more reliable then the others(Rockwell/Vickers/Brinell) or do they each have their own advantages/disadvantage and what are those?

[@MaterialsScience2000]

Answer to "Is one test seen as being more reliable then the others(Rockwell/Vickers/Brinell) or do they each have their own advantages/disadvantage and what are those?": They are all reliable, but they have their own pros and cons. Briefly: Rockwell is easy to fully automate, Vickers offers the possibility to produce very small indents (smaller than a material grain), Brinell the possibility to produce rather large indents (good for testing inhomogeneous materials such as cast irons in one test and get the average hardness).

[@vejet]

Thank you for the quick and concise answer.

[@jeevanselvaraju7449]

MaterialsScience2000

[@VinayKumar-jq3ed]

Sir please tell what is (0.2) and (500)

[@MaterialsScience2000]

Answer to "Sir please tell what is (0.2) and (500)": The two numbers are used in the equation to convert the measured depth of indentation e into "nice" or "convenient" hardness values of up to 100.

[@moinulshdu]

good job

[@nathanlubbe3676]

makes much more sense

[@tirus7472]

Brother pleas tell me the HRC of mild steel

[@MaterialsScience2000]

Answer to "Brother pleas tell me the HRC of mild steel": Mild steel is too soft for HRC measurements; hardness values of around 0 or even negative values would result.

[@hewdrillingrigs5232]

What is HRC

[@MaterialsScience2000]

Answer to "What is HRC": HRC is an abbreviation (or rather a symbol) and means Rockwell Hardness scale C.

[@vijaykumarjones4060]

✨✨

[@sanjibbarman1404]

God blesss you sister

[@muratcelikel8623]

bizden kimler izledi :D

[@aneesh0011]

Ok

[@Zemo-j7e]

was diese zemo

[@tomhunter6158]

Many mistakes. A copy of current ASTM E18 ( or the European equivalent) should be at hand. After every change in test load and indenter you are required to verify correct operation of the tester by checking with a test block. No certificate of calibration visible on the tester. You open your self up to a law suit by using uncertified results. The surface of the gear is too rough for accurate reading. The surface should be ground and polished. The specifications are in the ASTM manual. The gear was induction heat treated, thus the gear teeth a very hard HRC 60 and the body of the gear less hard HRC 45. You choose to test the part on the boundary between the two zones, a pointless operation with no value in the number generated. To test the gear teeth cut out a section of the gear teeth, grind and polish to metallographic finish and then use vickers with one kilogram load. To test the body of the gear you grind and polish a spot and use rockwell as close to center of gear as you can safely test.

[@MaterialsScience2000]

Answer to "Many mistakes ... ": Thank you very much for your detailed comments! I generally agree with almost all of your comments. There are even more issues that need to be considered, and most of them are addressed in the ASTM or EN standards. Why did we do it this way? Our intention was to show the basic principle of HRC hardness testing without going into the details. We do that in all of our videos. The next step would have been to explain all the specific details that need to be taken care of.

[@SlopedOtter]

That guy walks like he has watched KZbin tutorials on how to walk but has never actually done it

[@gheegggggg]

why use non standard unit kliopond? kgf is same much beter

[@MaterialsScience2000]

Answer to "why use non standard unit kliopond? kgf is same much beter": Both of them are non-standard units. It is an interesting topic, why there is still a reference to these units. It has to do with old units, the problem of expressing the hardness just as a number and some more points ...

[@tituszrecsko1869]

Nagyonjolett🙈

[@parthasarathymuthukrishnan4392]

COULD HAVE BEEN ELABORATE

[@nauman8030]

Please Make more Videos. This is the only channel on Material Science that is good. You guys can help us (little first year undergrad kids) in understanding concepts.....Please

[@logansmith4776]

Great video, helps me understand the process for parts that I buy within the aerospace industry

[@TWalsh2]

Since they removed his gear this guy only has reverse.

[@bapestaa]

i rate that my drilla

[@linus8759]

HOLA, ¿QUÉ TAL?

[@apm2649]

Scene💥

[@nureenayuni5018]

syu single ges

[@alexisbizaguirre7022]

in spanish pless

[@vijaykumarjones4060]

🔥

[@tonyapascarella3368]

The video is very good. Is there a way to contact you to get permission to use this video on my website which sells knives. I think it will help people understand what the Rockwell Harness number means when looking for a knife. Thanks.

[@MaterialsScience2000]

Answer to "The video is very good. Is there a way to contact you to get permission to use this video on my website which sells knives. I think it will help people understand what the Rockwell Harness number means when looking for a knife. Thanks.": Downloading and hosting the video on your own website is not permitted due to the standard license. However, you can always put an internet link from your own website to the video. This can be done in different ways. Some of them are very attractive.

[@rizwanraza3152]

Thank you very much angela i hv seen all video n i found that helpfull for me

[@sixfootdworf9545]

Why not use Newtons (a standard unit of energy) to measure the force applied to the object, after all, Newtons are an exact and standard measurement of energy.

[@MaterialsScience2000]

Answer to "Why not use Newtons (a standard unit of energy) to measure the force applied to the object, after all, Newtons are an exact and standard measurement of energy." Well, Newtons are the unit for force, not for energy. But the question, why in many areas of hardness testing the old force unit kilopond (or kilograms force) is still used, is a very old and long one. It has to do with the idea of leaving away the unit in the result of the hardness test, with the problem of changing to the "new" unit Newton, and other points. Sorry, too long to explain here.

[@shubhamsrivastava6028]

link for Rockwell hardness test B scale please

[@mohdizzatlayman4770]

Apa nama alatnya

[@AliHasan-gj9tb]

what is different between rockwell hardness test or brinell hardness test ?

[@kamilqurbanov375]

Ali Hasan hala cevap arıyorsan cevaplayabilirim

[@saidiskandar11]

Any new videos coming out soon?

[@YourAnonymousGuy]

thank you for sharing, very usefull .

[@vishwassharma]

Thanks

[@sk8yunky6]

you forgot to seat the indenter

[@MaterialsScience2000]

Answer to "you forgot to seat the indenter": Thanks for the comment. I hope I understand you correctly. Typically, the indenter must be used multiple times with a calibration test piece before a proper Rockwell hardness test (not shown in the video). This enables the indenter to be set and a test of the machine itself. In addition, after the end of the standard dwell time of the indenter with the minor force (preliminary load), the depth of indentation is tared (set to zero). This is done automatically by the machine in all tests.

[@JonnyKV93]

Thanks .. :)