What are 1 2 3 blocks?

[Brian Rupnow]

I see the term 1 2 3 blocks referred to in this site and on the machinists website, and I don't know what they are. Can someone please explain to me?---Brian

 

[Mike N]

Precision ground block of steel 1" x 2" x 3"

 

[jack404]

Brian they are as described

precisely ground blocks of steel

they are used like parralells to get a job square
some have threaded holes in them for mounting

i have a larger set that i used when cutting rails to get a perfect parralell cut

2 such blocks held to a plate with bolts can be used like a large Vee block to hold pipe inline and parralell

i also mount them to hold a Vee block to work a right angle one angle through the hole in the 123 block the other rest in the Vee on the Vee block this way i know both angles are perfect

thay have a lot of uses but basically its a tool to ensure you get the right angle, or right angle if you get what i'm saying

very handy to have

cheers

jack

 

[tel]

very handy to have

.... that was gonna be my answer - they have a multitude of uses once you get aholt of a pair.

 

[Brian Rupnow]

Thanks guys. One more thing that I have learned about this machining business.

 

[Tin Falcon]

Brian do not feel bad. I know what 1-2-3 blocks are but up until a couple of years ago I had not really used them .Keep in mind I have been trained and have worked as a machinist. I asked on another board what are the various uses for the 1-2-3 blocks the answer I got from one guy was you may as well ask what a spoon is used for .
I did not think it was a stupid question but he did I will not mention names because this guy is a respected published author and very experience machinist.
Since then i just started using them for whatever seemed right and got creative. I use them a lot for machining the edge of a plate 3 inches wide or so just put one on either side of the work piece to stiffen the setup.
The big brother twins are 2-4- 6 blocks same thing but scaled up.
Tin

 

[artrans]

Every day is a school day

 

[rake60]

We had a training session at work a few years back.
The older gentleman who was the teacher of that training session got a bit
off topic there one day.
He was a retired engineer / shop owner / machinist / hobby machinist / teacher.

He wanted to make his own 1 2 3 blocks and a small set of V blocks so he
made the plan for them and machined them to + 1/4"
Then he heated the up to cherry red and threw them outside behind the shop.
After 3 weeks, he brought them back in and machined them to + 1/8" on
all surfaces. Heated them up again and threw them outside to stabilize.
A month later he brought them back in and machined them the the final specs.
This time he was pretty sure the internal stresses on the material had been
given away. He was right.

He had made them 30 years before meeting us.
30 years later the 1 2 3 blocks and V Blocks measured NO indicated run out
on the most sensitive of measuring devices.

I wouldn't have the patience to spend 2 years making 1 2 3 blocks when you can
buy them for $20.
Knowing a man who did have that patience...
Well, I don't know how to put those feelings into words...

Rick

 

[shred]

1-2-3 blocks are one of those things "everybody" said "you should get" when I was starting out not too long ago, so I bought a cheap set and rarely even looked at them for the first 6 months. Now I find myself using them quite a bit-- bolt them together to get a 90-degree angle that can move; rough-square up a machinists vice with a table by slapping one alongside; use them as tall parallels in the lathe chuck for short work; use them to support thin stock above the vice; hold one on the lathe chuck or work to quick-square a parting tool; etc; etc.

 

[kvom]

The first use I was taught at school this year: Assume your lathe has no DRO and you want to turn off a precise length of stock, but it's greater then the 1" a dial indicator on a mag base can measure. Hold the block against the carriage to add 1, 2 or 3 inches of reach to the DI.

Making a pair 1-2-3 blocks is a project at my vo-tech school for those learning heat-treating and surface grinding.

 

[mklotz]

I have an interesting use for 1-2-3 blocks. Say you want to measure the taper of a tool or workpiece.

Lay the 1-2-3 blocks on a surface plate with the 1" dimension vertical. Put the tapered item between them so the axis of the taper is vertical. Lay your calipers flat on the upper surface of the blocks and measure the diameter of the tapered item. Call this dimension d1.

Now repeat this process with the 2" dimension of the blocks vertical. Call the measured dimension d2.

You now have two part diameters measured exactly one inch apart. The half-angle of the taper can be found from:

angle = arcsin [(d2-d1)/2]

Double this angle to find the included taper angle.

Since the blocks provide a nice flat support for the calipers, it's easy to get accurate diameters spaced a known amount.

Since I make mostly smaller models, I've made myself a set of half-size blocks - 0.5-1-1.5 inches. They're as handy, at least to me, as the full-size blocks.

 

[Philjoe5]

Marv, Kvom,
Thanks a lot for those suggestions. Those are things I'm always trying to figure out. I never thought about using the 1-2-3 blocks that way :bow: :bow:. These applications remind me of something a student of mine once said - "I can't wait to graduate so I don't have to learn anything else". Poor kid missed the whole point :'(

Cheers,
Phil

 

[shred]

I snapped a swarfy pic of a 1-2-3 block in action as a vice stop. Lots of ways to skin this particular cat, but this one is quick and easy.

 

[Stilldrillin]

Hmmmm........
I learned of 1 2 3 blocks, on here, last week.

That`s after 40+ years as a production miller in rock drilling manufacture! ??? :

But I did have a large selection of assorted parallels.....

 

[BobWarfield]

Hmmmm........
I learned of 1 2 3 blocks, on here, last week.

That`s after 40+ years as a production miller in rock drilling manufacture! ??? :

But I did have a large selection of assorted parallels.....

Yep, I'd imagine that being in the UK a 25.4-50.8-76.2 block just wouldn't be very memorable!

Cheers,

BW

 

[Kludge]

Yep, I'd imagine that being in the UK a 25.4-50.8-76.2 block just wouldn't be very memorable!

True dat. It would make too much sense.

Actually, the base dimension should be some fraction of the width of Queen Elizabeth's foot (the original QE, not this one) measured in wheat grains during her coronation precisely at the moment they plopped the crown on her royal head. Eventually, that measure would become so ingrained in the Imperial system of measure that no one would notice that, like the inch, foot, cubit and mile, there is no reasonable way to get from one unit to another without fudging a bit. That fudging was done along the way to make things work out more or less consistantly despite the somewhat odd multiples required to get from one to another.

Oddly enough, this system is still favored in some more or less civilized corners of the world and is deeply loved by those who use it, so much so that England recently was successful in telling the EU to stick it rather than become all metric. You go, England!

Best regards,

Kludge, the Historian. ;D

 

[Stilldrillin]

Yep, I'd imagine that being in the UK a 25.4-50.8-76.2 block just wouldn't be very memorable!

Cheers,

BW

Nice one, Bob!

Hmmmm..... I have just remembered......
Long ago, I made a pair of screwjack blocks, drilled & tapped for 5/8 whit capheads.
Still got `em, somewhere.....

The blocks measured 1.75" x 2" x 2.25".

Guess they`ll be 44.45 x 50.8 x 57.15 blocks?

Kludge.

I spent the last 20yrs or so making rock drilling components on a (metric) Takisawa machining centre.....

All components were in Imperial measure & tolerance, apart from the button bit insert holes, which were metric, & graded in microns. :

Engineering`s a funny old game....

 

[scoop]

wishful thinking Kludge.Imperial units of measurement are fading fast.I have had the experience of starting out in engineering in inches and slowly converting to metric.During this time I realised that metric is by far the best system of measurement.As an Englishman I know I should go and wash my mouth out with soap,but its true.No more fractions to deal with,ie not having to add 1-31/64" to 3-7/16" just to arrive at 4-59/64",which you cannot measure with a micrometer or a vernier,then having to convert to 4.9219" only then to find that if I was working in metric is only a few tenths of a thou' over 125mm,which if I was working to a tolerance of +/- 0.010" I could have measured with a steel rule.Sorry about all the confusion but it is a fact of life that working in tens is a doddle compared with twelves,sixteenths etc etc.More confusing is having engineering drawings that are dimensioned in metric but still retain all the thread detail in imperial so that just when you think its safe to throw all your old imperial stuff out,somebody draws a 10-32 thread on his latest creation instead of keeping to metric forcing you to search the skip outside for the correct gauges.Hope I have not wound anybody up with my pro metric ramble,any body else got an opinion.Maybe a vote on it is required.

best regards Steve C.

 

[Kludge]

wishful thinking Kludge.Imperial units of measurement are fading fast.

Can you still buy a pint in your local friendly pub?

No more fractions to deal with,ie not having to add 1-31/64" to 3-7/16" just to arrive at 4-59/64",which you cannot measure with a micrometer or a vernier,then having to convert to 4.9219"

So why not start with decimal inches? Our lathes, mills et al don't have fractions on them - or none that I've seen do - so why dimension in fractions to begin with? That's something I've never quite understood. The only time I used fractions on drawings was when I was in classes. The rest of the time, it was all decimal for precisely the reason you state. Fractions are almost as evil as I am.

More confusing is having engineering drawings that are dimensioned in metric but still retain all the thread detail in imperial so that just when you think its safe to throw all your old imperial stuff out,somebody draws a 10-32 thread on his latest creation instead of keeping to metric forcing you to search the skip outside for the correct gauges.

Okay, you asked for it. Soon as I have my tool kit to a reasonable point, I shall build something using as many different thread systems as I can. :big: :big: :big:

any body else got an opinion.Maybe a vote on it is required.

Oh, boy. ASking for an opinion here is dangerous. 1992 members (at this writing) will yield 2500 opinions at least. ;D

Oh. What are we voting on because mine's for pizza.

BEst regards,

Kludge

PS: If you read the body of my message, you'll note that I was having some fun. Honest!

 

[Brian Rupnow]

When I started in engineering in 1965 everything was in British Imperial.--inches, feet, miles, and pounds (weight). Then, our blind and stupid government leaders, decided that we in Canada would go totally metric to be in line with our foreign trading partners. Somehow they overlooked that country with which we share our longest common border, just south of us who account for 85% of our foreign trade, has 100 times our population, and was NOT going metric!!! Then ensued a long and very painfull 5 year period when all engineers and designers were forced to learn and work in the Metric system. Educators quit teaching feet and inches in the public schools, high schools, and colleges, and proceeded to teach all the kids to work in metric. However, all of the machinists and mechanics who had a ton of money invested in tools that measured in British Imperial basically said "Screw this!!", and as soon as a metric blueprint hit the shop floor, it was converted to British Imperial by the people who had to work from it.---with many numbers being "rounded off". All of our steel mills shrugged their shoulders and went on rolling structural steel shapes based on feet, inches, and pounds, as they always had. After about 10 years of this nonsense, many of the smaller machine shops quietly said "Enough of this damn foolishness" and went back to using British Imperial. However, the big companies with trade ties to Europe stayed working in Metric. Now we have the damdest mish mash of measurements styles, preferences, and confusion that the world has ever seen. Any engineer or designer must be prepared to work in either British Imperial or Metric, depending on who the customers is. And the kids somehow have all managed to graduate and move into the workplace, not being certain of the difference in a foot, inch, millimeter or cubit!!!