My favorite part of Sunday mornings is hot coffee and new D4A! Best automotive channel on the interweb! Thank you so much for all your amazingly thorough and easy to understand videos!
I'm an automotive engineering student and I didn't even know anything about oil clearance thanks for all the educational content. Your channel is awesome m8 :)
Finally finished the install on my turbo upgrade on my MR2T today! Feels so great to be finally finished (exactly in time for spring and my birthday next week)! Had to share with someone who understands.
Hey just a quick tip, i learned from my grandfather how to use the brown wrapping paper used to prevent rust on automotive parts, this paper cut into strips can be placed behind bearings to ajust the bearing clearance to a better smaller value without having to buy new bearings ..also may need to pass a file on the bearing parting surfaces to create a clearance when tightening the bearing caps...just avoid getting this paper wihin 0.5cm of the bearing lock tabs which are supposed to prevent the bearing from spinning in the bore...
I finally realized my mistake in zeroing the dial bore gauge in the micrometer. I moved front part of it up and down not the spring loaded back part to zero it. I never knew whether i should push it in completely or if i should take any point in the middle and zero that. Now i found out that i have to do it the other way around. I don't know if somebody understands what i mean but you definetely made my day👍🏻
Plastigage. Extremely accurate regardless of claims to the contrary. AND it measures actual torqued clearance which micrometers do not. Divide by 2 to get the actual oil clearance. Cost $3.
Whenever you buy a used engine, you need to check the bearing clearances, no matter what, You must remove all the big end bearing caps and inspect the bearings, the crankshaft and you need to measure oil clearances, to determine if you bought a lemon and whether you need to take it back for a refund or exchange most used engine Japanese imports have warranties for their engines Also you need to do a compression test but most used engine Japanese imports do compression tests before they sell them, but you must also check
You may not be able to return the engine if it's been opened. I bought a junkyard engine here in California and the valve train had rusted solid. I took apart the engine, tried to free up the valves, and put it back together. When I tried to return it, they wouldn't accept it. If the junkyard/importer or whatever has match marked the crank pulley or other parts, it's likely they won't accept a return.
I use micrometers just like that one everyday at work. This is a really good video as usual, but I'm a bit a skeptical of the sliding the micrometer method. Also, using these tools is a matter of developing a lot of tactile sensitivity. If people want to try this as amateurs it is great, but it takes quite a while to learn to use these tools precisely, and in the beginning it is hard to know if you are doing it right if you don't have other people around to compare your results with
Very good information. This is the only way to check for taper and out of round. And also for ordering the right size bearing, to make sure you have the right oil clearance
I gotta say I love this channel. One thing I would love to see more of is how all these details change when you change the engines "purpose"... so when you marinize a v8, switch a diesel to say kerosene or biofuel, run a car angine as a plane engine and run it at constant high rpm or upside down.. All those things noone sane does.. :D
This guy knows how to simplify complex engine subjects easy to understand as i watched some other videos on this subject I couldnt understand like I understand from this guy 👍
Damn I just spun my rod bearing last week too. I was so lost on how to fix this and was considering just getting a new motor from the junkyard but now I might try to fix it. This video is totally kick ass man thanks a million you have no idea!!! Always look for your new videos
Absolutely TOP car channel!!. Love Scotty's, but not even close as clearly didactic & accurate as your 'in - depth' info!!.. Many thanks & Blessings!!.. 🤗🙏🙏🙏🙏
when you are on the loos side use bit thicker oil and crank up oil pressure. Check if you can find higher flowing oil pump for your build, more flow = more pressure for your loose measurements.
For those watching and learning. Know that him spinning the crank in the bearing saddles is for demonstration purposes only. Don't spin your crank until the main caps have been installed and torqued-to-setting" .
Good video. I'm a machinist and I never use the ratcheting knob on a mic. Also never met a machinist who does. Also measure rod bolt stretch instead of using a torque measurement whenever possible.
I have done this very meticulously, but when I measure with bearing shells installed vs plastigauge or measuring a calibration ring, I always see about an extra 10µm clearance. I seems like the bearing shell surface is so soft, the inside micrometer digs into the shell's top coating 5µm (0.2 thou) on each side. I use trimetal bearings. I can see the area the tool interacted with. Since then measure all the parts, but the final step is always plastigauge. Honda K-Series engines use very small clearances. 10µm is pretty much halve of the clearance tolerance with minimum crank main clearance being only 17 µm.
I'll be prepared for you next video about bearings in different materials, because I want to start a engine modification and the first step is to install molybdenum bearings
set micrometer to journal diameter, set a telescoping t bore gauge to the bearings under torque in the caps, then use feeler gauges to see gap when you put t bore gauge inside of micrometer
I spun a bearing and had the engine rebuilt at the machine shop. 500 miles later, it is rod knocking and I sent the whole truck for warrantied repair. I now suspect they didn't clearance the bearings accurately (loose) because my pressure light was flickering on idle and my oil pressure gauge fails to bring pressure up on hot-oil start up. thank you for giving me more insight on what possibly happened with this video.
When it comes to bearing clearances, you've got what you've got. There's not many ways to adjust it and the majority of people don't have the capability to do it.
you can always take it to the machine shop to grind the journal or close and hone the caps as needed. The important thing is to take accurate measurements so you can make an informed decision. Its far better than just winging it.
@@shriramvenu The ideal way to do the job is the same as boring for the pistons. Buy the pistons first then bore the block to suit. Buy the bearings then grind the crank to give the correct clearance. Both jobs are for the machine shop, not the DIYer at home.
Very good video, but I have a doubt, do mechanic really uses micromete that to inside, they just visually examine th Journal by observing the side ( unloaded area ) & judge if has become undersized.
Preemtive smash of the like Button comes rather early today :D Let's see what masterpiece we got here today.... yup another great video right there, well done. Gives one a good idea on what, how and why to look for those clearances in an engine.
Theres an old engine builders saying "too tight and EVERYONE knows. Too loose and only you will know." I always shoot for .002-.003 depending on journal size, but i kid you not when ive seen .006 and still showed adequate oil pressure on a couple engine designs
@@Milkmans_Son You measure at 4 locations and / or axially around the journal. But many modern bearing shell designs run more clearance on the sides the help with oil transport in the higher loaded centre sections of the bearing. To check for out of round journals, you need the micrometers, indeed.
Micrometer has to be held on the U shape body, where the name of the manufacturer is usually sticked, it reduce the error due to the temperature of your hand for example and this way you can dose all the measure to the same manner
Reminds me of the insanity that is Mazda RX8 stationary bearing journals. Those things keep running with the copper on the bearings stripped off. The only hint is the faintest of knocks because the crank on constrained by the rotor. Then it stops and never restarts. Unless you know exactly what to listen for it's a silent failure because it's nowhere near as loud as a standard piston engine.
Could you please a video about lubrication, like hydrodynamic and hydrostatic and where the are used in engine, bearings clearances to allow for hydrodynamic lubrication and im sure you would explain in better
I believe they are usually deliberately elliptical to a small degree, as shown in this video. This helps stabilise the oil wedge at high RPM, otherwise you can have 'oil whirl' issues that ruin the bearing.
Coming back to this video bc i took my block to a machine shop and in the following weeks i heard some complaints about that shop about valves being badly seated and stuff And now I'm worried that maybe they will mess up my engine
That was a really well done tutorial and should give people who will never build a performance engine some insight why it costs so much to have things done. The 0.001 / inch or mm is intersting, never seen a published number before. Does it change due to oil viscosity, (particularly in respect to modern engines using 0w-20, etc?) I imagine it does as the Toyota clearance was smaller than 'theoretical' clearance.
Thank you, glad you found the vid useful. Yes, running a low viscosity oil with the 0.001 rule of thumb thing wouldn't be a good idea. Most of the new stuff runs closer to 0.0005 or even 0.0004. The rule of thumb clearance most applies to performance builds of popular and go to engine platforms. That being said even some relatively modern stuff runs large clearances and high viscosity from the factory, but it's mostly large v8 or v10 supercars and hypercars.
Awesome video. Pls i need your advice. I am an Electronics engineer but looking to setup a workshop to rebuild engines back to stock. I'm based in Nigeria, Africa. I ran this through a local mechanic but was discouraged that it's not profitable. That it would be be profitable to just sell the parts of the engine. Problem is most of the mechanics know nothing about precision in measurements. From your years of experience, is it possible to return worn out engines back to excellent shape?
Yes, of course engines can be rebuilt. It's done all the time. But you need a lot of experience to be good at it and costs are high if you want to do it right which also means you have to charge a lot. These costs are often hard to justify for cars where it's usually cheaper to just buy a good used engine. Rebuilding usually makes more sense on trucks, tractors and other industrial vehicles. Or on rare and valuable vehicles.
Does the temperature of the room or the parts will make any difference? If yes, what is the recommended temperature to be set before start getting the readings?
hello thanks so much for this vedio . when we mesur oil clereance using plastic gages the total value found in both side of bearing must be equal to the to value of oil clearenc given by engin manufactur or not . value of oil clearenc given by engin manufactur is for each side of bearings or must be divided betwin them
Turbo lag is a function of the turbo itself and is also affected by the plumbing. Is there anything more to be said than an inline engine has potentially shorter plumbing leading to the turbine? Packaging concerns make this not a sure thing, though.
your videos are great and informative. Could you maybe make a video about DIY exhaust? Picking the right exahust manifold, tube size, cat etc for power and displacement?
Hi, very good! Only a point… 6:41 (sorry for my English).. if circumference of micrometer is divided for 50 (you see 5, 10,…45, 0) so every step is 0,02 mm, the measure is 39.97 and 39.98, right?
0-150MM 0.01mm/0.0004 Inch Outside Micrometer set ban.ggood.vip/WVod
50mm-160mm 0.01mm Dial Bore Gauge bit.ly/36jYWQI
Dial Bore Gauge kit smaller diameters ban.ggood.vip/WVoz
Support d4a: driving-4-answers-shop.fourthwall.com/
istekli linkovi jel mozes ih refreshat ?
I love how this guy shares not only knowledge, but know-how also
Indeed
My favorite part of Sunday mornings is hot coffee and new D4A! Best automotive channel on the interweb! Thank you so much for all your amazingly thorough and easy to understand videos!
Amen!
I'm an automotive engineering student and I didn't even know anything about oil clearance thanks for all the educational content. Your channel is awesome m8 :)
Must be day 1 at uni
No wonder why the modern engines are so s..t 😂
Stop making cars so hard to work on
u should change your colleague.
@@byloyuripka9624 my career is about electronics and electronic systems design (like ADAS). We have nothing to do with power plants tho.
I also use platicgauge for checking bearing clearance. It may be old school, but its quick and simple,accurate and it works.
I don’t even have a car but I NEED TO KNOW THIS!!!😂
It's always good to learn new things
Same here. I don't own a car but i need to know. 🤣
👍
I am going to buy me some main bearings and connecting rod bearings and then I'll buy me a car 😁
Ha3x... maybe its because you like engineering stuffs.
I used to operate these grinding machine for the crankshaft...
As the owner of a very old diesel engine I happen to live on top of (in a boat), you're an absolute godsend. Thank you so much for this!
Finally finished the install on my turbo upgrade on my MR2T today! Feels so great to be finally finished (exactly in time for spring and my birthday next week)!
Had to share with someone who understands.
Congrats my friend!
Correct
Hey just a quick tip, i learned from my grandfather how to use the brown wrapping paper used to prevent rust on automotive parts, this paper cut into strips can be placed behind bearings to ajust the bearing clearance to a better smaller value without having to buy new bearings ..also may need to pass a file on the bearing parting surfaces to create a clearance when tightening the bearing caps...just avoid getting this paper wihin 0.5cm of the bearing lock tabs which are supposed to prevent the bearing from spinning in the bore...
Thanks so much for this. I am a vibration analyst and all your videos on Recip. Engines are joy to me. I appreciate.
I finally realized my mistake in zeroing the dial bore gauge in the micrometer. I moved front part of it up and down not the spring loaded back part to zero it. I never knew whether i should push it in completely or if i should take any point in the middle and zero that. Now i found out that i have to do it the other way around. I don't know if somebody understands what i mean but you definetely made my day👍🏻
Plastigage. Extremely accurate regardless of claims to the contrary. AND it measures actual torqued clearance which micrometers do not. Divide by 2 to get the actual oil clearance. Cost $3.
so true, cant beat old school.
@user-gj8oq7fw1u Micrometers are older school than plastigauge.
Whenever you buy a used engine, you need to check the bearing clearances, no matter what,
You must remove all the big end bearing caps and inspect the bearings, the crankshaft and you need to measure oil clearances, to determine if you bought a lemon and whether you need to take it back for a refund or exchange most used engine Japanese imports have warranties for their engines
Also you need to do a compression test but most used engine Japanese imports do compression tests before they sell them, but you must also check
You may not be able to return the engine if it's been opened. I bought a junkyard engine here in California and the valve train had rusted solid. I took apart the engine, tried to free up the valves, and put it back together. When I tried to return it, they wouldn't accept it. If the junkyard/importer or whatever has match marked the crank pulley or other parts, it's likely they won't accept a return.
I just love this videos its allways a perfect sunday when they come. When I meassure the clearence i use plastigauge.
I use micrometers just like that one everyday at work. This is a really good video as usual, but I'm a bit a skeptical of the sliding the micrometer method. Also, using these tools is a matter of developing a lot of tactile sensitivity. If people want to try this as amateurs it is great, but it takes quite a while to learn to use these tools precisely, and in the beginning it is hard to know if you are doing it right if you don't have other people around to compare your results with
You're definitely this does take some "feel" that only comes with repetition
I am also a machinist.
Very good information. This is the only way to check for taper and out of round. And also for ordering the right size bearing, to make sure you have the right oil clearance
I'm sorry for that retention algorithm, I clicked out of one of your other videos for this one
I gotta say I love this channel. One thing I would love to see more of is how all these details change when you change the engines "purpose"... so when you marinize a v8, switch a diesel to say kerosene or biofuel, run a car angine as a plane engine and run it at constant high rpm or upside down.. All those things noone sane does.. :D
There's some really good video ideas here!
Amazing once again! Not all things have been said to school.
This guy knows how to simplify complex engine subjects easy to understand as i watched some other videos on this subject I couldnt understand like I understand from this guy 👍
Damn I just spun my rod bearing last week too. I was so lost on how to fix this and was considering just getting a new motor from the junkyard but now I might try to fix it. This video is totally kick ass man thanks a million you have no idea!!! Always look for your new videos
Did you ever fix it?
Absolutely TOP car channel!!. Love Scotty's, but not even close as clearly didactic & accurate as your 'in - depth' info!!..
Many thanks & Blessings!!..
🤗🙏🙏🙏🙏
Who in their right mind would dislike this mans videos?
Best car engine channel !
Best automotive maintenance Chanel!! Keep going!
when you are on the loos side use bit thicker oil and crank up oil pressure. Check if you can find higher flowing oil pump for your build, more flow = more pressure for your loose measurements.
Would this be a good application for the notorious Lucas oil?
Thank you so much for this video. I never undestood very well the measures of the crankshaft before watching this video.
For those watching and learning. Know that him spinning the crank in the bearing saddles is for demonstration purposes only. Don't spin your crank until the main caps have been installed and torqued-to-setting" .
Good video. I'm a machinist and I never use the ratcheting knob on a mic. Also never met a machinist who does. Also measure rod bolt stretch instead of using a torque measurement whenever possible.
Thank you for your time and sacrifice to open my eyes and brain in measurement .
D4A upload.. Oh, right, it's Sunday.
Some people like to use plastiguage to measure the clearance, if used correctly its a valuable tool
I have done this very meticulously, but when I measure with bearing shells installed vs plastigauge or measuring a calibration ring, I always see about an extra 10µm clearance. I seems like the bearing shell surface is so soft, the inside micrometer digs into the shell's top coating 5µm (0.2 thou) on each side. I use trimetal bearings. I can see the area the tool interacted with. Since then measure all the parts, but the final step is always plastigauge. Honda K-Series engines use very small clearances. 10µm is pretty much halve of the clearance tolerance with minimum crank main clearance being only 17 µm.
It's really amazing the tolerances we can achieve with modern manufacturing/tooling.
This guy is very good he makes it very simple
I'll be prepared for you next video about bearings in different materials, because I want to start a engine modification and the first step is to install molybdenum bearings
set micrometer to journal diameter, set a telescoping t bore gauge to the bearings under torque in the caps, then use feeler gauges to see gap when you put t bore gauge inside of micrometer
I spun a bearing and had the engine rebuilt at the machine shop. 500 miles later, it is rod knocking and I sent the whole truck for warrantied repair.
I now suspect they didn't clearance the bearings accurately (loose) because my pressure light was flickering on idle and my oil pressure gauge fails to bring pressure up on hot-oil start up.
thank you for giving me more insight on what possibly happened with this video.
When it comes to bearing clearances, you've got what you've got. There's not many ways to adjust it and the majority of people don't have the capability to do it.
you can always take it to the machine shop to grind the journal or close and hone the caps as needed. The important thing is to take accurate measurements so you can make an informed decision. Its far better than just winging it.
@@shriramvenu The ideal way to do the job is the same as boring for the pistons. Buy the pistons first then bore the block to suit. Buy the bearings then grind the crank to give the correct clearance. Both jobs are for the machine shop, not the DIYer at home.
Very good video, but I have a doubt, do mechanic really uses micromete that to inside, they just visually examine th
Journal by observing the side ( unloaded area ) & judge if has become undersized.
Preemtive smash of the like Button comes rather early today :D Let's see what masterpiece we got here today.... yup another great video right there, well done. Gives one a good idea on what, how and why to look for those clearances in an engine.
D4A, THANK YOU SO MUCH for this amazing info! I'm getting ready for my ASE A1 and being able to see the theory in action is extremely valuable.
We were teached how to measure stuff in engineering, but this is so much easier to understand :)
You are one of the best, tutor very clear and simple explanation ❤️
Theres an old engine builders saying "too tight and EVERYONE knows. Too loose and only you will know."
I always shoot for .002-.003 depending on journal size, but i kid you not when ive seen .006 and still showed adequate oil pressure on a couple engine designs
you can use plastiguage for this mesurement as well. it's much faster and have good accuracy
it's actually what the picture shows in the workshop manual ;)
How does plastigauge tell you if something is out of round?
@@Milkmans_Son plastiguage is for measuring bearing clearence only.. it cannot tell you if something is out of round :)
@@Milkmans_Son You measure at 4 locations and / or axially around the journal. But many modern bearing shell designs run more clearance on the sides the help with oil transport in the higher loaded centre sections of the bearing. To check for out of round journals, you need the micrometers, indeed.
Legend ! King of the "Interesting" Stuff
Thank you for your vedeo bearing clearance is very important
rod journal (muñon de biela) main journal (muñon de bancada)
Just taking a few notes for those who don't know the names in spanish.
Excellent basics!! Thanks Big!!
Micrometer has to be held on the U shape body, where the name of the manufacturer is usually sticked, it reduce the error due to the temperature of your hand for example and this way you can dose all the measure to the same manner
You are really good man. Thanks
I know how to do all this stuff. I just enjoy watching your videos!
can you also meassure the holes with an
internal micrometer?
can you make videos about large 2 stroke marine engine? and other marine engineering stuff?
Reminds me of the insanity that is Mazda RX8 stationary bearing journals. Those things keep running with the copper on the bearings stripped off. The only hint is the faintest of knocks because the crank on constrained by the rotor.
Then it stops and never restarts. Unless you know exactly what to listen for it's a silent failure because it's nowhere near as loud as a standard piston engine.
Could you please a video about lubrication, like hydrodynamic and hydrostatic and where the are used in engine, bearings clearances to allow for hydrodynamic lubrication and im sure you would explain in better
Just use the bearing manufacturer book for suggested measure and grind the crankshaft accordingly .
Some people say you shouldn't spin your crank before you torque your main caps down because the bearings aren't round until they are torqued.
I believe they are usually deliberately elliptical to a small degree, as shown in this video. This helps stabilise the oil wedge at high RPM, otherwise you can have 'oil whirl' issues that ruin the bearing.
@@nerd1000ify Possibly - but it's still fair to say that until they are torque down, the bearings don't assume their proper shape.
Love the blower bearing gap! 😂👈
🤣
Once again brilliant. But what I really want to know is how does a cannon fire threw the center of a B-109 Messerschmitt engine
Please, Is there a way to file and measure a journey for the main with the engine in the car?
Coming back to this video bc i took my block to a machine shop and in the following weeks i heard some complaints about that shop about valves being badly seated and stuff
And now I'm worried that maybe they will mess up my engine
Perfect info I was looking for thx
Thanks for all your videos
That was a really well done tutorial and should give people who will never build a performance engine some insight why it costs so much to have things done. The 0.001 / inch or mm is intersting, never seen a published number before. Does it change due to oil viscosity, (particularly in respect to modern engines using 0w-20, etc?) I imagine it does as the Toyota clearance was smaller than 'theoretical' clearance.
Thank you, glad you found the vid useful. Yes, running a low viscosity oil with the 0.001 rule of thumb thing wouldn't be a good idea. Most of the new stuff runs closer to 0.0005 or even 0.0004. The rule of thumb clearance most applies to performance builds of popular and go to engine platforms. That being said even some relatively modern stuff runs large clearances and high viscosity from the factory, but it's mostly large v8 or v10 supercars and hypercars.
@@d4a Thanks for reply. I've said it before but I'll say it again, I have no idea how you find out this stuff but I'm glad you do.
Tnx sir for all your support pls explain about cylinder bore tappernes and out offroundness
This is straight gold!
What clearances would u use in hi performance diesel dryblock and head ,for tractor pulling 10 seconds max power per run?
You are great teacher 👍
Awesome video. Pls i need your advice. I am an Electronics engineer but looking to setup a workshop to rebuild engines back to stock. I'm based in Nigeria, Africa. I ran this through a local mechanic but was discouraged that it's not profitable. That it would be be profitable to just sell the parts of the engine.
Problem is most of the mechanics know nothing about precision in measurements.
From your years of experience, is it possible to return worn out engines back to excellent shape?
Yes, of course engines can be rebuilt. It's done all the time. But you need a lot of experience to be good at it and costs are high if you want to do it right which also means you have to charge a lot. These costs are often hard to justify for cars where it's usually cheaper to just buy a good used engine. Rebuilding usually makes more sense on trucks, tractors and other industrial vehicles. Or on rare and valuable vehicles.
OLÁ. A medição movimentando o micrometro é o que provoca a deformação da "rosca" do micrometro nas áreas mais usadas. ABRAÇOS
I love your work
Plz make iconic engen video on
Gtr r32 r33 r34
Hope it gives more insight about oil grades and what difference can they make.
A genius at work....I like it!
You are correct, the engine park should never come into contact with udders, So keep them away from the cows.
Does the temperature of the room or the parts will make any difference?
If yes, what is the recommended temperature to be set before start getting the readings?
Engineering inspection department's are air conditioned to 20 degree centigrade. All iso measurements are at that temperature.
@@lancefawcett1809 thanks
synthetic oils are thinner so the tight clearances are necessary.
Might want to look in to a set of snap guages.
Can these measurements be done without removing the engine from the vehicle? I.e. just removing the oil pan?
You are awesome, best video ever explaining this :D
Thank you! FYI, the micrometer link is bad. Can you link again? I’ll definitely be buying it :-)
hello
thanks so much for this vedio . when we mesur oil clereance using plastic gages the total value found in both side of bearing must be equal to the to value of oil clearenc given by engin manufactur or not .
value of oil clearenc given by engin manufactur is for each side of bearings or must be divided betwin them
I need your I have questions about bearings and clearance
How do you adjust the clearance? Crankshaft comes a certain standard size, bearings come a standard size!
Can you do a video about turbo lag on boxer engines vs inline
Turbo lag is a function of the turbo itself and is also affected by the plumbing. Is there anything more to be said than an inline engine has potentially shorter plumbing leading to the turbine? Packaging concerns make this not a sure thing, though.
A noob question - is it safe to use old camshaft bolts to measure the inside dismeter? If bolts are stretched isn't going to alter the measurments?
Some say it does but I've never seen it happen in practice. Torque to spec and measure away
This is a good work. I like it too.
Fascinating.
Indeed.
your videos are great and informative. Could you maybe make a video about DIY exhaust? Picking the right exahust manifold, tube size, cat etc for power and displacement?
What is the base of the clearance size?
Sooo how do I measure without wasting the torque-to-yield bolts?
Very clearly explained! 👍
Can you explain how the (x)(0.001) formula does not change when the metrics of the x value change 1:51
Dude! I love this channel!
The best channel!
When installing the journals do you just torque the bolts without adding the extra angle on top and are the bolts single use?
Thank you very much for this very informative video.
about iconic engines, how about the long produced H-Engines from SAAB?
Hi, very good! Only a point… 6:41 (sorry for my English).. if circumference of micrometer is divided for 50 (you see 5, 10,…45, 0) so every step is 0,02 mm, the measure is 39.97 and 39.98, right?
This means "thick oil " will say : '' so , you have chosen death"😂😂