# Precision Gauge Blocks



## Brian Rupnow (Apr 19, 2021)

Precision gauge blocks---how many of you have them and how often do you use them? I can buy an 81 piece set for around $180 but I'm not sure if I would use them enough to justify their cost.---Brian rupnow








						81PC STEEL GAUGE BLOCK SET GRADE AS 2
					

Busy Bee Tools is Canada's largest Woodworking & Metalworking retailer. Find power tools, woodworking tools & metalworking tools at factory direct prices.




					www.busybeetools.com


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## goldstar31 (Apr 19, 2021)

Guilty as charged, Me Lud-= Metric and Imperial and a 5 inch sine bar plus dial gauges etc in tenths of thous.
Honest answer before the verdict is read?  Forget it all,

However, I would love to have a Facimt machine and a Double Slide Rule.
Reason -- for the Hell of it - again.


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## tornitore45 (Apr 19, 2021)

I bought a set of (cheap) precision disks, about 0.8" diameter with a #10-32 threaded hole in the center, various thickness from 0.050" to 1"  They are ground with the "intention" to be accurate but for what I pay I am not counting on much.
They agree with the mike.
I bought them because like most of us I am a toolhaloolic.
I do find them useful and used them a few times.  Is a bit like adjustable parallel, I could use them more if my imagination was better at spotting the perfect use.

I used them for:
Operation where a measurement or offset or setting up must be repeated
I interpose one between the carriage stop and the carriage to give me accurate movement
Use narrow one to measure thin slots
I do not like much to readjust my height scale because of loosening 2 picking it up to see where to set it, lock the fine adjustment and fiddle with it, then lock the scribe. So I set up the size(s) I might need repeatedly to speed up the process of tracing a part.
I like to verify with a 6" scale most of my mill table movement to be sure I am not 0.1" off. In some situation the scale does not fit with all the clamps and what not around the set up. A cylinder of the correct dimension is easier to reference in between an edge and a line or a tool.
I used them as I would have used a machinist jack when the jack would be too tall.


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## doc1955 (Apr 19, 2021)

I have a set and use them quite often. They are nice to have when you need them I have some dial bore gauges and use them to set them up.


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## Vietti (Apr 19, 2021)

Dumb question no doubt, but how do you use them to calibrate a bore gauge.  Measuring bores is the bane of my life!


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## Tim Wescott (Apr 19, 2021)

I think that's the sort of tool you get thinking you'll use it once every decade, and then slowly find yourself using it all the time.


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## Sprocket (Apr 19, 2021)

"Measuring bores is the bane of my life!"
I have to agree with that. I could seldom get the "T" gauges to agree two measurements in a row, and even when I thought I had it right, my OD part might not fit my ID part as well as I'd like, and I know the OD parts were correct.
I got one of these  www.travers.com/dial-bore-gage-set/p/57-017-678/ this winter, and I think it is making things easier. Directions say to set it with a micrometer, then you are using it as a comparison. I use it as you would a "T" gauge, note the reading, then use the mike to compress it to that reading, and I have my ID. While I doubt I'll ever use it to 6", it will read that. You can see if there is taper as you slide into a bore, and actually measure how much as you go.
Only done a few ID's since, but I have liked the results.
Doug


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## Vietti (Apr 19, 2021)

Doug,

Thanks for the info.  Looking at bore gauges on eBay I see different styles.  Wonder which system is best, for these prices it should pay to get the right one.

Thanks to all.  John


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## xpylonracer (Apr 20, 2021)

I have sets of gauge blocks, an imperial set by Coventry to 6" and a very nice Russian 80 piece set to 150mm, the latter were bought at a car boot sale in the Czech Republic in 1987 for very little money, the Coventry set were bought at a factory closing sale and again cost was very low.
The most used is the 0.50mm which I use for tool setting on the milling machine, many of the others have never been used since I had them but on the few occasions when used there is no substitute.


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## Brian Hutchings (Apr 20, 2021)

I have an 81 piece set that was returned from calibration with many pieces that did not meet the standards. It was cheaper for the company to buy a complete new set that to replace all the duff ones. I offered to dispose of the old set on guarantee that not would find their way back into the company!
The calibration cert is still with them and the worst error is 109 millionths of an inch which is less than I care to worry about. They are frequently used for marking out, setting up on  the mill and occasionally for length setting on the lathe.
Brian


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## Rotormac (Apr 20, 2021)

Vietti said:


> Dumb question no doubt, but how do you use them to calibrate a bore gauge.  Measuring bores is the bane of my life!


Set up the required measurement with the slip gauges with an extra piece at each end protruding.  The distance between the extras is the setting for the bore gauge.


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## Tim1974 (Apr 20, 2021)

I use every day but for home shop  use ? There expensive there’s all ways a different way but if you have the funds why not


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## clockworkcheval (Apr 20, 2021)

Pure greed once led me to buy a set of 92 (now 91) Hommel Class 1 Precision gauge blocks. To my amazement I use the set quite often. In the first place on the lathe between carriage stop and carriage, in the second place to measure slots and in the third place to measure and set angles with a sine bar based protractor. The precise setting of carriage and angle on the lathe is for precision work like making gear and pinion cutters.


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## Charles Lamont (Apr 20, 2021)

I have a good pre-owned Matrix set, bought 15 or more years ago for something like £90 on Ebay. I thought at the time they were a bit of a luxury, but I have never regretted buying them. They are used quite often, and often for tasks that would  otherwise be difficult to do.


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## kvom (Apr 20, 2021)

I have a set that gets used on occasion.  But the 1" block I use as a tool setter on the CNC mill vey frequently.


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## kquiggle (Apr 20, 2021)

I bought a set several years ago, and use them only occasionally, but I'm glad I bought them because the few times I have needed them they were very helpful.  Also quite useful for confirming that your micrometers and calipers are working properly. I would not consider them a "must have" for general metal working - more of a "nice to have" once you have your basic metal working tools in place.


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## L98fiero (Apr 20, 2021)

Vietti said:


> Dumb question no doubt, but how do you use them to calibrate a bore gauge.  Measuring bores is the bane of my life!


Here's a picture from the Wikipedia site, I have a similar but longer clamp and just use a couple of pieces of ground, square HSS for the anvil faces at the end, not as accurate as the real thing but as good as you'll need 99% of the time. It's not as good as a reference bore and takes a little fiddling to set the bore gauge but it's better than trying to set the bore gauge with an outside mike. Obviously this won't work for setting the three point bore mikes.


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## Richard Hed (Apr 20, 2021)

Rotormac said:


> Set up the required measurement with the slip gauges with an extra piece at each end protruding.  The distance between the extras is the setting for the bore gauge.


Rotor,
In your icon, you have a gyrocopter.  Do you have a vid of it flying?  How many people does it carry?  What is the horse power?  How far can you fly on a tank of gas?


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## awake (Apr 20, 2021)

Brian, I understand and affirm your hesitation on this, and am pleased to offer a solution. If you will go ahead and buy them, and have them shipped to me, I will test to see how often they get used and give you a report. Note that we will need a sufficient length of time to account for the intermittent nature of my machine shop time - maybe 5 years?

No, no, no need to thank me; I am happy to offer this service free of charge, simply out of the goodness of my heart. Please let me know when to expect the gauge set.


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## goldstar31 (Apr 20, 2021)

But you see that you really need to use a controlled temperature water bath to get the best out of your Jo Blocks.  Well, surprise, surprise but tou do.

It's a bit like checking viscosities using a a PRS Viscometer or a perhaps Number 4 Ford cup.
Again, I DO  know  Statistical Quality Control. Never mind the why's and wherefores but it is not far renoved from the maths in Cost Accountancy

But in most cases,  a set of Jo Blocks is overkill and something simpler and you can't have somebody with a set to jumble and spill so something could be desirable.
 A set of homemade 'blocks' i say 1/16th or a set in millimetre intervals often suffices!. I have  cheap and far from nasty set of professionally made metric ones!
Sometimes a 6" Ruler 'stuck' to a square  block can be used to set up work- Quickly.

Again, I made up a set of spring loaded indicators for setting up stuff in a 4 jaw independent chuck.

Of course-- ho ho ho, I use a centre pop and - that's it.
And of course, I have rather wonderful DRO system on the Myford and a cheap and actually quite nasty so called DRO

 Oh and perhaps, I have drifted off but I have--- shush-- stub drills

N


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## Mike Henry (Apr 20, 2021)

I have a used Mitutuyo gauge block set of unknown quality and an import set and use them just often enough to make them worth their cost.  I tend to use gauge pins a lot more often to check sizes of holes that are too small for the usual hole measuring instruments.  For larger holes where accurate sizing is needed I've gradually acquired used name-brand tri-mikes.  Those aren't cheap, even used, but are satisfying to use.  The ring gauges to calibrate them are pretty expensive, especially as I bought those new to be more certain of their accuracy.  For holes between 0.2 and 1.2 inches where extreme accuracy isn't needed, I use a Starrett 700A internal micrometer.


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## methuselah1 (Apr 21, 2021)

I have several sets; Johanssen, Pitter and Matrix. if you've got them, you use them- more especially if you don't have DROs on everything. Some of my sets are out of industrial limits, not that it bothers me at home, the Pitters were retired simply because they are imperial. I have never paid over £40 for a set, and although setting a sine bar can be done just as easily with an adjustable parallel, the cost of a set of those is more expensive than my blocks.

They also come into their own when packing between crankshaft webs during multi-throw crank manufacture, and obviously for calibrating intruments. Sadly, for three point bore micrometers, there isn't much of a substitute for a ring gauge.


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## Rotormac (Apr 21, 2021)

Richard Hed said:


> Rotor,
> In your icon, you have a gyrocopter.  Do you have a vid of it flying?  How many people does it carry?  What is the horse power?  How far can you fly on a tank of gas?


It's a Bensen, really a flying chair. 



 flew for the first time just before everything shut down last year so the only vid I have is 400Mb and not suitable for uploading here.  Single seat, engine VW bug 1.8L 70Hp (for 5 mins) then 40HP for cruise.  Carries 18L unleaded, cruises at 45MPH, good for a an hour with 5L in reserve.  
Philip.


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## ajoeiam (Apr 21, 2021)

Hmmmmmmmmmm - - - interesting  - - - - how heavy a 'body' is your 'flying chair' (grin) rated for please?


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## ignator (Apr 21, 2021)

Brian, I purchase my new set off eBay about 6 years ago. I use them with sine bars and my sine plate. On my lathe I have a sine bar I made a quick bracket to clamp to the side of the compound for precision setting of the angle.
You can get an 81 piece set, new for $92USD off eBay. They are grade B, but they all come with a sheet showing the error of nominal, and they are higher tolerance then even a tenths micrometer can read. You can buy used, but finding a complete set is luck
I found a photo of the sine bar clamp mount, but I'm using pin gauges.
I have a test indicator mounted to a long test bar from my tail stock, but I could have it on the ways of the lathe as well. This method sets the compound angle by sliding the carriage back and forth to zero the indicator movement. I went to gauge pins as wringing them was an issue (not degreased enough). I thought the 6 different boxes of gauge pins was crazy at the time, but they are handy when testing for bore size, or in this case of setting a sine bar on the side of the compound.


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## ignator (Apr 21, 2021)

Rotormac said:


> 400Mb and not suitable for uploading here.


Download a free program, HandBrake, I use this to compress large mp4 videos to 2-8MB size depending on the compression.


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## Richard Hed (Apr 21, 2021)

Rotormac said:


> It's a Bensen, really a flying chair. View attachment 124731
> flew for the first time just before everything shut down last year so the only vid I have is 400Mb and not suitable for uploading here.  Single seat, engine VW bug 1.8L 70Hp (for 5 mins) then 40HP for cruise.  Carries 18L unleaded, cruises at 45MPH, good for a an hour with 5L in reserve.
> Philip.


I often live in the philippines where Moalboal is about 3 hours from Cebu City. That is, it is three hours by philippine mehtods--in US or Europe it would be about 45 minutes.  So I often thimpfk about a flying chair to go to the city, avoid all the pollution and agonizing ride.  The difference in max 2 hour round trip and 6 hour round trip--you can easily understand this.  The odd thing is that this trip by bus could be shortened SO EASILY if the roads were straightened and a few bridges put in.  They don't seem to understand that dynamite is very cheap, a caterpillar works wonders and "cut and fill" is a basic technique of road building.  Every two years (or less) they rip up the road and put new concrete in because the last job didn't use any rebar to keep the concrete from breaking.  It's really about feeding the construction companies (which ar generally owned in some way, often by hidden corporations, by the local politicians) public monies.  In Europe and US, the corruption is hidden quite well, but in 3rd world, the corruption is basically on top. 

How long did it take you to build your flying chair?  Do you feel safe?  What is the material of the rotor/wing?


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## Rotormac (Apr 21, 2021)

How long did it take you to build your flying chair?  Do you feel safe?  What is the material of the rotor/wing?

I built it first as a towed kite.  Towed behind a small car 30MPH great fun.  I rebuilt it last year with the Veedub on board.  The blades are extruded 6061.  It's good for a 250Lb lump on board.  It performs better with a lighter driver, I'm 165Lbs and it climbs at approx 1100FPM. (even with a set of gauge blocks on board ;-) 
Roads in Ireland have improved drastically since we joined the EU.


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## Richard Hed (Apr 21, 2021)

Rotormac said:


> How long did it take you to build your flying chair?  Do you feel safe?  What is the material of the rotor/wing?
> 
> I built it first as a towed kite.  Towed behind a small car 30MPH great fun.  I rebuilt it last year with the Veedub on board.  The blades are extruded 6061.  It's good for a 250Lb lump on board.  It performs better with a lighter driver, I'm 165Lbs and it climbs at approx 1100FPM. (even with a set of gauge blocks on board ;-)
> Roads in Ireland have improved drastically since we joined the EU.


That's about my weight:  I am a 250 lb lump.  But if you had a kite, was it one big wing or two?  What if you crashed?  Do you have photos?

The roads in the philippines are being widened in and near the cities but they ignore other more easily made projects such as the cut and fills and a few small bridges.  Very basic stuff.


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## Rotormac (Apr 21, 2021)

A while ago, when I had coloured hair.  Approx 2000AD.  Notice no registartion.  The blades in the pic (which flew very well) were hombuilt, mostly from 1/8" ply and mahogany, from the Bensen plans.  the tow hook was on the pointy bit at the front.  Build took about a month with another month for the blades.  Sand, fill, sand, paint, sand..........


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## awake (Apr 21, 2021)

Impressive! What sorts of inspection or procedures are needed to ensure that the blades are holding up as intended? I have to confess that I would be a wee bit nervous about trusting blades that I myself had made! But that is based on my own limits and abilities. I'm very impressed that you were able to craft this.


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## Richard Hed (Apr 21, 2021)

Rotormac said:


> View attachment 124743
> 
> 
> A while ago, when I had coloured hair.  Approx 2000AD.  Notice no registartion.  The blades in the pic (which flew very well) were hombuilt, mostly from 1/8" ply and mahogany, from the Bensen plans.  the tow hook was on the pointy bit at the front.  Build took about a month with another month for the blades.  Sand, fill, sand, paint, sand..........


It's difficult to believe those rotors would be able to provide enough lift.  Don't they have to be rotating?  Being towed doesn't seem like it would work.


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## Rotormac (Apr 21, 2021)

At the kite stage - as it's not legally an aircraft - there's no legal requirement for inspection, just your own desire to remain whole.  Strictly speaking (and although it can be done) it's not legal to release the tow and land untethered.  Once the tow is released you transition from kite to aircraft and all that that implies.  As a powered aircraft, all the regulations for hombuilt aircraft apply.  I've never flown under power with the homebuilt blades although I have several associates who have.  They're not as efficient as the alloy blades but do provide more than adequate lift for the single place Gyro.


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## Rotormac (Apr 21, 2021)

In the Kite, the rotors (20ft diam) have to be hand-started up to about 60RPM, the wind then accelerates them up to flying speed, about 350RPM.  Then you're off.


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## Richard Hed (Apr 21, 2021)

Rotormac said:


> In the Kite, the rotors (20ft diam) have to be hand-started up to about 60RPM, the wind then accelerates them up to flying speed, about 350RPM.  Then you're off.


That is quite amazing.  I never would have guessed.  So how do you hand start the rotors?  Are you sitting in the flying chair when you start them?  Is there a crank or something?


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## Rotormac (Apr 21, 2021)

If you're tall enough, you can reach up and push the rotor around.  Otherwise a friend can do it while you're strapped in.  If there's a bit of wind, it's fairly easy to get up to 100 - 150RPM, then the first hundred yards of the tow usually gets you there.  One of my friends set up a system using a bicycle crank for the pre-spin but eventually went back to simple hand pushing.
Towed, you get 15 - 20 seconds in the air before it's time to get back down, that's on a 700 yard grass strip.
I do recall my first take-off as quite a rush ;-)


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## ajoeiam (Apr 22, 2021)

Rotormac said:


> How long did it take you to build your flying chair?  Do you feel safe?  What is the material of the rotor/wing?
> 
> I built it first as a towed kite.  Towed behind a small car 30MPH great fun.  I rebuilt it last year with the Veedub on board.  The blades are extruded 6061.  It's good for a 250Lb lump on board.  It performs better with a lighter driver, I'm 165Lbs and it climbs at approx 1100FPM. (even with a set of gauge blocks on board ;-)
> Roads in Ireland have improved drastically since we joined the EU.



Hmmmmmm - - - - Roads in Ireland - - - - - when I was there I was taught the phrase "1/2 mile up and down for every mile" (LOL) although the country roads are FAR better than here in rural Canuckistan!

Rates for 250# lump - - - - oh well - - - - I need its big brother.

You must be the guy the airplane and car manufacturers decided to model their test dummies after - - - - grin! 

Guys like me hate airplane and car seats!!!!!!!!!!!!!!!!!!!!!!!!!
Have a good buddy who is that weight too - - - you guys are pretty rare though. 
(I'm about 2 ft across the shoulders and the last time I checked I can still squeeze body weight in either hand so its not just mid section - - - - grin!)


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## Rotormac (Apr 22, 2021)

Our roads are not so polarised.  I remember driving out of SF one time taking 30 mins to cross the 6 lane parking lot to get to the car pool lane.  It was advising a fine of $197 for illegal usage!!  Where did that number come from?
Both of my kids live in the US so I do have a small experience of the roads there.  Great major roads and wicked minors ;-)
Drove up one autumn from Vermont into C'land once and enjoyed it.
I must have been sitting beside you on my last flight over and you should share some sympathy for opressed minorities like me ;-)
When I started flying I was 220# and couldn't climb out for nuts so I worked hard to get down to where I am now.  As for squeezing my own weight, never gonna happen.  Grin grin grin.
Stay safe.  P.


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## ajoeiam (Apr 22, 2021)

Rotormac said:


> Our roads are not so polarised.  I remember driving out of SF one time taking 30 mins to cross the 6 lane parking lot to get to the car pool lane.  It was advising a fine of $197 for illegal usage!!  Where did that number come from?
> Both of my kids live in the US so I do have a small experience of the roads there.  Great major roads and wicked minors ;-)
> Drove up one autumn from Vermont into C'land once and enjoyed it.
> I must have been sitting beside you on my last flight over and you should share some sympathy for opressed minorities like me ;-)
> ...


Fine number - - - - came from some idiot bureaucrat turkey's brain fart - - - imo! 
Where you got to north of Vermont is some 3000 km east of where I'm at - - - grin! 
Of I will share sympathy with you re: oppressed minorities but not re: seat sizing - - - - grin! 
I have tried to contact seat manufacturers wanting to ask their engineers if they have ever looked a people in a large meeting area (aircraft terminal or mall or theater) The number of people that actually resemble that standard engineering dummy size is way under 2% - - - - if its even that big - - - - so why are they designing for that size. 
I can feel your pain at being an oppressed minority - - - - but I hate flying and am wishing I could have the seat from my old 1980 VW Rabbit (Golf) again - - - - it fit and was oh so comfortable (drove as much as 2800 miles in two days and had no motility issues when I got out of the car!!).

Have yourself a wunderbar day!!!!!

Careful with dat flying stuff - - - - its a rush - - - but it can be a bit too much rush sometimes!!!


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## kstrauss (Apr 22, 2021)

methuselah1 said:


> Sadly, for three point bore micrometers, there isn't much of a substitute for a ring gauge.


A bearing race makes a substitute that is probably more than sufficiently accurate for home use.


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## methuselah1 (Apr 23, 2021)

kstrauss said:


> A bearing race makes a substitute that is probably more than sufficiently accurate for home use.


Absolutely! They also make very fine circular parallels- but although they're not bad, two races of the same type may not necessarily be the -exact- same width. The "important" tolerances regard the diameters.


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## Tim Wescott (Apr 23, 2021)

Gauge blocks are great for measuring groove widths -- like those piston ring grooves you cut that were apparently smaller than the cutter, over on the other thread.

Basically, if you get them, you'll find uses for them.


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## trlvn (Apr 26, 2021)

A bit of an offshoot question...

How precise are feeler gauges?  I have multiple sets of feeler gauges even though I've never bought any new.  They all came in auction box lots.  Of course, each leaf is labelled as being a certain size but are there "A" grade sets that are spec'd to a higher tolerance?  Is there a typical +/- for common sets?

Just curious,

Craig


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## ignator (Apr 26, 2021)

trlvn said:


> A bit of an offshoot question...
> 
> How precise are feeler gauges?  I have multiple sets of feeler gauges even though I've never bought any new.  They all came in auction box lots.  Of course, each leaf is labelled as being a certain size but are there "A" grade sets that are spec'd to a higher tolerance?  Is there a typical +/- for common sets?
> 
> ...


The problem I've encountered with feeler gauges, they are punched from sheet stock, and typically have a raised edge. They work OK for setting engine tappets, as the central part away from the edge is  used. I have old used feeler gauges as well, that were used back in the day, and are all dented up from being used to set the valve clearance. I think this happened when the engine was running.


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## tornitore45 (Apr 26, 2021)

Considering that feeler gauges come in 0.001" interval  the need to distinguish 0.003" from 0.0032" seems purely academic. Still I would guess the manufacturing ability to grind to thickness within 0.0001" is achieved without special effort.   Bends, dings and buggered edges are another matter.


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## trlvn (Apr 27, 2021)

After a bit of searching, I found tolerance info on a 26-leaf Mits set.  +/- 0.0002 inches for leaves up to 0.007" thickness.  Allowable variation increases to 0.00075" for leaves over 0.020" thickness.



			https://api.sbsimpson.com/storage/documents/mti/950184.pdf
		


Even the lowest spec Jo block set is far more precise than that, right?

Craig


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## ignator (Apr 27, 2021)

trlvn said:


> Even the lowest spec Jo block set is far more precise than that, right?


+8/-4 microinch max for grade 3, less then 1 inch. At least what I found. Seems the set I have, I've seen numbers that range +/-30 microinch on the calibration sheet included, so this must be an economy set of blocks.


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