Precision Lapping 101

In this video we take a look at a couple of lapping methods and the kinds of geometry they produce. We also take a look at some of the A2 tool steel parts and gages that just came back from heat treating. We examine some of the surfaces and do some initial surface lapping and evaluate the surfaces with the helium monchromatic light and an optical flat.

[@johnalexander2349]

"I'm not a robot." You know who says that? Robots, that's who.

[@somebodyelse6673]

I know who the robot is. Dale Derry. Guy doesn't blink at all in most of his videos.

[@josephssen]

hey, i passed the turing test on only my third try!

[@OldFella547]

Hi Tom. i always like watching your posts as it brings back memories & even though I've been retired for many years when I worked as A Toolmaker at a Government Factory & during The Vietnam War we made heaps of Fuse Timing Components for Both The Australian & American Services we had Vacuum Furnace which was very handy to Harden very small Punches & Dies as we could make them to Size Then harden them without any movement like what happened in The Salt Pots. Also we used The Diamonds on Lapping Plates.. We also Rolled Diamond Dust onto Small Mandrills for Jig Grinding very Small holes.

[@NuclearHedgehog]

Great video. The elegance of producing premium surfaces with this method is just beautiful.

[@EddieTheGrouch]

"Just because it's shiny doesn't means it's flat" - Nicest thing anyone has said to me. My shiny bald head thanks you!

[@EddieTheGrouch]

Lol. At least won't need an optical flat to find the belly button.

[@kellerrobert80]

One of your best. Well, organized and presented. Keep up the good work.

[@aeromech8563]

Hi Tom, awesome video as always. I'm an aircraft engineer and started my career building jet engines for B707s one of the jobs I enjoyed was lapping the carbon seal face plates we had a 16" cast lap plate with a diamond slurry, straight line rubbing was the name of the game count to five then turn 90° and repeat as you can imagine a hard chrome faceplate took a while. Gee the hours I spent doing this haha good memories. There's something special about old school engineering that satisfied me and still does. It's an art.love the show you do. 🤠🇦🇺

[@fcarp1685]

This channel is fascinating! Thank you for posting for us!

[@bugrobotics]

Awesome content as always. Thanks for sharing. The epoxy embedded Renzetti stones look great!

[@jhueth3969]

Thanks for all your time with the video, just got a lapping job coming up and can use all the techniques I can get.

[@edsmachine93]

Great video. You're definitely the next level and beyond. Very interesting Technology and explanation. Thanks for sharing. Take care, Ed.

[@James-fs4rn]

looking forward to learning how you maintain the geometry during lapping. thanks for another great vid Tom.

[@jackbm99]

love your vids, I learn something every time I watch them

[@philipyoung9002]

Thank you for this most informative tutorial! I learned a lot about lapping.

[@eclecticneophyte2581]

Very good info as always. Still working to get my plates flat, but it's also good to see what is possible, and how it is achieved. Thanks Tom! 👍

[@LetsRogerThat]

I learned a lot from the lap series and the light and lens measurement technique is amazing

[@vnyggi621]

Your're a really good teacher, thanks for the video!

[@drewnix7201]

Thats a deep understanding a love for knowledge to master this art. And a shop load of tools. Much respect

[@stephenpeterson7309]

I find this fascinating. Why, I don't know. I'll never need to do this. I'm not a machinist and at 70, it's not likely I will become one but I like your videos anyway. Nice work.

[@Landrew0]

Tom's videos show us a side of machining we rarely see. Part of his job is to explore the best techniques for specialized machining jobs. From seeing the techniques he can share, it make us all a lot wiser.

[@JamesChurchill3]

That tool steel is such a nice colour after heat treating. Great stuff!

[@chrisstephens6673]

And I thought you were going to talk about cats drinking milk and not spilling any, You learn something new every day.

[@doright6461]

Thanks for an awesome video! Reminds me of a time when I was challenged years ago with putting together a lapping department for Pratt & Whitney bearing seal plates for main LPT shafts on JT8D, JT3D, GG4 + GG3 engines. The roughly 5" to 10" in. diam. thin plates were a repair. Had to grind off chrome, plate again, rotory grind .00005 flat and and lap. Tolerance .00002 and 5 micro. I used Speedfam and Lapmaster revolving tables w/ 9 to 5 micron slurry and a polish on the lapmaster with a 5 micron lexan film all under unconstrained free weight. The trickiest part I fond was cleanliness between the work and flat. I used a 12" flat. I used similar to drag method but dragged wipe from under work instead of work off wipe. Always that 'pinch' of fiber on the ending edge. I then resorted to moving the part away from last wipe contact to 'roll' any fiber out from under the part edge. Yes, I put work on flat with mirror under it with a 12"x2" thick circular flat which is cumbersome to move around. Clean sterile clean was the key to achieve 1 dispersed circular fringe without suction meaning it was simply hugging the flat which was flat within .000002. Glad I'm making chips again ;- ) Thanks and thumbs up!

[@sriramneravati5048]

This video was so captivating. I appreciate it! I cant wait to get into some high accuracy lapping sometime in my future :)

[@georgeliu7575]

This is just fantastic. Great talent!

[@RGSABloke]

Hi Tom, as I mentioned on on of Robin's recent videos, when watching both your channels, my head tends to explode getting my brain around these measurements. As you eluded to 'All that glitters is not gold'. Kindest regards. Joe.

[@markenna5955]

You missed your Calling. You are a great Teacher, Now i finally understand the process, I might need to know that someday. Thank You.

[@stanjarmolowicz]

that is incredible educational video ..every minute of it is fore price of gold . thank you for shearing

[@Wobblybob2004]

I can't believe you have made over a hundred lapping videos. Good man, keep em coming. :-)

[@EmmaRitson]

very interesting stuff, as always we learn a lot.

[@bpoweski]

Thank you. You’re an exceptional teacher.

[@TheZoraccer]

Hi Tom! Maybe you find this useful : aluminum foil from food or hardware store (especially 30-40um) is pretty precise, thickness deviation is less than 1um for the whole roll. I use pieces of this foil as a "bib" for my surface plate while running a 3d-printed planetary lapping machine with abrasive powders on it. Just a tiny drop of viscous (220cSt) oil on a plate, decently spread on surface, holds foil sheet very strong. Surface plate is always clean, and you don't have to wipe it while changing abrasive number. Parts from this DIY lapping machine are almost as flat, as an optical flat, checked that recently.

[@Muuce]

Инженер that sounds like a great setup, could you do a video on it?

[@oxtoolco]

That sounds very interesting. I have never heard of lapping done this way but it appears to have all the ingredients with the exception of grooves in the lapping plate. Film thickness would have to be controlled well to get good results. Thanks for the comment and suggestion. Cheers, Tom

[@TheZoraccer]

Yes, grooves do a lot of good job with worn-out abrasive particles, foil method has this disadvantage. Classical flat-lapping machine uses interchangeable disks with grooves, but they are big, heavy and rather expensive. Thank you again for all your videos, it's a pleasure to watch!

[@TheZoraccer]

Why not, will try to do a short clip.. If you agree to deal with my horrible "russian english")

[@TheUglydandy]

Ай промис ту дил виз ё хоррибл рашн инглиш, соу вэйтинг фо ё видео игэрли.

[@hamiltonpianos]

Excellent video! Hoping you have a "Part 2" in the pipeline, as I'm very keen to see how you go about lapping for square and parallel, as that's something I need to do in my workshop soon :)

[@jacklav1]

That was a fantastic video

[@AaronCaviness]

Hypnotic! Jezz! Got to watch it again

[@bmalovic]

Hi Tom, another great video. When you clean sandpaper on a plate, wrap rare earth magnet in some plastic foil (even thicker plastic bag will work). Just gently swipe over sandpaper and it will collect all swarf. Unwrap magnet over the waiste bin, all swarf fall of, and magnet is clear. Of course it works only for steel/iron, and may not remove every tiny bit of swarf, but you do not get swarf and grit flying in the air around. Another thing is that loose abrasive grit will stay on top of sandpaper and continue to cut, so you get more from same sheet. Yes I know this is not lapping, but you can consider it "rough" preparation, and there are situations where this is just good enough (of course not for toolmakers instruments).

[@Cpl.Cadaver]

Thanks for the very informative video.

[@JonesAndGriesmann]

Wow thank you for this video Tom.

[@temptorsent]

Hi Tom, another great video! I just wanted to mention that you can further improve your accuracy and increase time between resurfacing your laps if you rotate them periodically in addition to rotating your part. An even more ideal option, especially for larger parts, is a heavy stand you can walk circles around while lapping.

[@oxtoolco]

I do rotate the laps as I use them. Just didn't happen to show in the video. Good point as a reminder.

[@MrJugsstein]

Thanks Tom Enjoyed the content. Very Zen for me.

[@SteveSummers]

Nice video Tom, thanks for sharing 👍

[@chevystuffs5971]

Man, I'm so jealous you can do cool shit as an exercise. You are doing something right man. Beautiful work.

[@rickeycallen]

FINALLY BACK TO NORMAL TOM!!!! THANK GOD!

[@corylannon8546]

"11 millionths - pretty flat" Love this channel man. As a hobby woodworker/welder/machinist I now have an idea as to how un-flat the backs of my chisels are.

[@TC-um2ti]

This is very interesting and illuminating, I appreciate the education in new precision terminology such as, dinguses, humpty bumptys, little du-du-dah-dits and little hick-ups, etc. As these terms are new to me, I beg your tolerance in my spelling, I’m sorta wingin’ it. On the serious side, this was extremely interesting and I look forward to more

[@bobbybeard67]

Excellent teaching!!!

[@stevecanny1583]

Super good Tom! Thanks for this :)

[@josephwilson6651]

Missed your detailed description of what you are doing, Hope everyone is well. You have obviously been quite busy,to bake any meatloaf. (i do enjoy it so very much) I Thank You Mr. Lipton

[@Rorschach1024]

Used to work at a machine shop that ground Steel mill rolls, and these rolls were ground to a 3 microinch finish. At that level of finish, the surface actually becomes dark, the linear scratches set up an interference pattern with visible light causing the reflections to cancel each other out.

[@mattcurry29]

Great video Tom. Keep them coming. Matt C.

[@rickhickman2730]

I need to make surface plates for lapping the bottom of my handmade infill wooden hand planes 😁 great work

[@R.E.HILL_]

Hope you make a new video soon... it's a pure joy to watch you do your thing... ☺

[@1jtolvey]

GREAT VIDEO !!!

[@LonersGuide]

Great video. I feel like I just got a practical introductory education in lapping flat surfaces.

[@billbrennan8405]

Thank You Tom for another great video ! When I worked in the die shop 45 yrs back we would grind magnetic blocks to the chuck and first grind them in flat. Then we would grind the surface till it cleaned up, backing off the the mag chuck power we would turn the part 45 Deg and using the same height take a pass across the part. Then turn the part 45 Deg in the opposite direction and run across the part again at same height setting, we called this cross check grinning which would leave a cross check pattern but would remove many of the humps and bumps. Very Interesting Video & Helpful. Bill B

[@oxtoolco]

Hey Bill, That makes for pretty flat ground surfaces. There is another technique called spot grinding but its not for the faint of heart. Probably not a good thing to show in video form. Thanks for the comment. Cheers, Tom

[@somebodyelse6673]

That sounds pretty similar to what Don Baily shows in this video. kzbin.info/www/bejne/eaS3k4p3qpWeY9E

[@bcbloc02]

This is not the world I work in but it is cool to see and learn about none the less. :-)

[@REALIVH]

the same here :) have asses to a milling machine and Lathe both Manuel in a Makerspace also others hand tools, but only a pin-welder no TIG or MIG

[@ZyNoOne]

Great video! Keep it up!

[@jamescole3152]

Interesting. Good job

[@torstenb5248]

„I have a much bigger one, but it tends to squeeze all the air out.“ 😂

[@vikassm]

Super useful! Between your videos and those from Robin Renzetti, One of these days I'll get down to reconditioning these surface plates lying around neglected.

[@TomZelickman]

Makes me wonder if optical comparator prices jump every time you publish one of these videos. I think it's great that you are giving yourself a good challenge as well. Looking forward to seeing you soon, sir. Tom Z

[@CyrusTabery]

Euv lenses are 0.1nm figure and finish over the 600mm lens. I really liked your explanation and demo of the optical measurement of the surface. Scanning probe demo would also be good for me and perhaps your audience. Thanks again!!

[@hdheuejhzbsnnaj]

Yes. Monday is my Sunday, and I get Precision lapping instructions for breakfast.

[@routermonkey2855]

I got to spend some time many years ago with a master optician - he made large amplifier slabs for laser fusion research, a foot in diameter or more, an inch thick, and flat and parallel to 1/20 wave - and one of his tricks was to draw a few lines across a piece with a wax pencil before setting the reference flat on it. This was soft enough not to scratch anything, easy to remove, and gave the right spacing to easily see the fringes while bridging over any micro-dust that might be on the surface.

[@R.E.HILL_]

This is incredibly nerdy... I love it. Thx for sharing... ☺

[@scottkenny8203]

11 millionths- Tom: "Meh. Its Pretty flat" 😁

[@hebrewhammer1000]

Thank you for sharing! It would have been interesting to see you inspect it with an dial indicator before and after lapping.

[@peteferguson7024]

Nothing, not even the world, is "flat" :). Good demonstration, thanks.

[@krazziee2000]

thanks for the video ,, good lesson...

[@nraynaud]

"Diamonds tend to settle out": worst James Bond movie ever. It's when he and the Bond girl have gained weight, their teenage kids are entitled brats, and their respective bosses belittle them at work.

[@allennelson1987]

Logical. Don't be a superspy. It's dangerous, you get tortured a lot, your ass gets whupped a lot, and and there is no way that you can top that, and I don't say that admiringly. It's better just to live an ordinary life, that way when you start living an ordinary life, it's not a disappointment.

[@Robertwclarke]

That's the first time I'd ever heard the word 'dingus' (19:12). It is now officially my favourite word. 1. Something whose name is unknown or forgotten. 2. A person regarded as stupid. 3. Vulgar Slang The p*nis. I also learned a lot about lapping. Thanks for the super video

[@Robonthemoor]

Perfection" thanks for sharing 👏

[@pasmrohydpump4697]

Thanks for the up load, your vids are helpful. Is there any way you can make a in depth video on optical flats? Like the set up and getting measurements, or understanding when it means to get into 2 lightbands or 3 lightbands. If not, do you of any other videos that might have this info?

[@dejanira2]

Very interesting to see what flatness really is. 🙂🙂🙂

[@dansquires2713]

No more figure of eight!! Thanks Tom this totally makes sense and I always hated it. Genuine thanks.

[@fupersly]

Hello love your videos! Would it be possible to do a video on how to achieve parallel surfaces while lapping? I think that would be really interesting content as I have not seen any video covering the subject.

[@RobertPerrigoOkiechopper]

Nice job.

[@CompEdgeX2013]

Always interesting. I'm in Brians camp tho....tractor stuff! ;-)

[@grishguillotine43]

Gorgeous

[@anthonygregory3022]

When I was at Vickers BEA system's we had a rotating table. Pour on liquid grind paste. Place in the piece leave for x amount of time.

[@chkishorilal]

Good. Keep it up😊

[@yamasaki.design]

Hi Tom, firstly great informative videos, you have a gift for explaining things... I'm particularly interested in trying to achieve greater precision with my tooling around in the shed. I'm interested in the pair of little honing stones you often use to clean up the machine table etc... What sort of grit are they, how do you keep look after them and maintain flatness? Cheers Paul I

[@forrestaddy9644]

THANK YOU!!! I've been ranting for years that lapping for flatness and dimension is a skilled and finicky procedure. Rubbing two surfaces together with Clover valve grinding goo does not constitute precision lapping. My experience has been with production lapping like on a LapMaster. I have no experience with toolroom lapping or even the traditional apparatus used to do it so have been frustrated by my own ignorance in mentoring others. "That's wrong. I don't know what's right, but that ain't it." is unpursuasive to say the least and sure as hell doesn't lead to enlightenment. This video has been a revelation for me and I hope for others laboring under the blithe delusion of rubbing etc. I'd like to see more particularly lapping to dimension, roundness, gage making, lapping media, and more. Thanks again. Most educational.

[@oxtoolco]

Hey Forrest, You can count on lots more controlled rubbing. That little pile of heat treat I showed contains many examples of the types of fancy rubbing you mention. All the best, Tom

[@EverettWilson]

Hey Tom, thanks for the vid! Do you have any learnings from lapping for squareness?

[@thor8334]

Thank you for this good vidéo man ! I recently discovered an intrest in lapping, i’m not a mecanic or anything but i just wanted to lapp the integrated heat spreader on my cpu to make it better at dissipating heat by having better contact with my water cooling cpu block. I do not have the tools for feedback anyway so maybe i shouldn’t touch it so i don’t make it worst :/ Have a good day dude and thanks again.

[@RRINTHESHOP]

Very nice.

[@oceanpout5232]

That was interesting Thanks much!

[@camcompco]

Awesome info, i have become obsessed with flat/square/straight/round over the past year, you have been helpful in my pursuit of the unattainable "perfectly". Question, do you know the name of the heat treat company that RR sent these to? thx much, John

[@ninivepaulcastillotorres9845]

very good

[@aion2177]

Awesome stuff :) Can you please make videos on how to handle round surfaces - inside and outside - for precision instruments let say.. and also how to make sure you have a right angle - if you don't already have one as reference ... something like the 3 surfaces trick.. what is the equivalent for for making 90 degree corners? Or even other types of corners like 120, 60, 30 degrees.. etc. Thank you :)

[@ROBRENZ]

Nicely done Tom, have you tried the kimwipe drag method of cleaning the part and the flat? I find it to be the fastest and most sure fire method. looking forward to seeing more on these parts. ATB, Robin

[@somebodyelse6673]

Final cleaning of industrial laser lenses is done by just dragging the lens paper, as well. I think it's a common practice with optics in general?

[@markschweter6371]

Yes it is indeed.... the ol' drop'n drag. (never dry!)

[@remz473]

Hi, Tom. I'm interested in how you were going to go about making that block square by lapping, without the standard squareness block in the grinder type setup. Thanks, Tyler

[@mniteen9486]

Please keep it up👍👍

[@hile6380]

Hello Tom. I am Asko from Finland. Thanks for great videos. I have 1916 manufactured Finnish made Karhula Sorvi, Sorvi means in English Lathe.. In spring She goes in my shop. She is very good conditition about age.. 210mm x 1500mm are dimensions. Maybee I take in spring some videos here. She,s weight is 1150 kg. Nice machine. Sorry my mistakes about writing. Try understand. All best for you and your Family from Finland.. T.Asko and Pimu, Pimu is my dog, 45kg.. Pimu means in english Pretty girl..

[@ominguti6345]

Great video to come and rewatch sometimes. I just noticed you were using a raiser block on the surface grinder at 21:02 but I can't figure out why? The wheel goes down all the way to the chuck so, why would one choose to use a raiser block?

[@MTknives]

I fell down the rabbit hole, where did the time go. :D Thanks :)

[@davidkierzkowski]

I would love to see what a hand scraped surface looks like under one of these optical blocks

[@wbfinley]

Hey Tom, You may have been asked this in the past but I would love to know where you acquired your apron! That seems to be best looking/functional shop apron I've ever seen. Do you happen to know or remember where you got it?

[@jmh8743]

thank you Tom

[@cptbimes1]

Laps to mirror finish, wipes residue off with paper towel. I got a chuckle out of that.

[@malteser0212]

How did you make the fully charged diamond lap? I feel like that deserves a video. (Also I don't find any video about that on the tube, nor any article or forum post on the www)

[@paulmace7910]

How do you charge the cast iron lap? If I remember the guys that did your plates had a roller that drove the diamonds into the lapping plate. Gem cutters use a tin lap with oil for their final polish. But like you say, just because it’s shiny doesn’t mean it’s flat.