This is your can seam micrometer.
You'll use it to measure your First Operation seam thickness
and your Second Operation seam thickness.
How your can seam micrometer works, is your inner barrel
is divided up into 25 thousandths (0.025").
Each small tick is 25 thousandths (0.025") and
where the 1 is that would be 100 thousandths (0.100") of an inch.
The outer barrel, if you notice, one full rotation
right to 0.024" will give you 0.025".
If you notice right underneath the zero on the inner barrel,
you'll see that first line which indicates you're at 25 thousandths.
So that being said, if you see 1 tick and you pass it and land on 15,
you would be at 25 + 15 = 40 thousandths (0.040").
In this case, we use Ball cans and
Ball specifies First Operation seam thickness to be 76 ± 2 thousandths (0.076" ± 0.002").
Here we have a First Operation seamed can.
We'll grab our micrometer.
Notice that the can seam micrometer, when it's sitting perfectly on the can
sits at a slight angle because the bevel on the inside of the can is not a perfect 90 degrees.
Rotate the outer barrel of the can seam micrometer
until you just touch the material and it sits on the can nicely.
Be sure not to over tighten as you'll get an improper reading.
Be sure to measure the can in four separate locations.
At my first location, I am reading 75 thousandths (0.075").
As you can see there are three ticks showing,
which indicates 75 thou plus I just passed to about 1 thou,
so you add the 1 thou to the 75 thou which makes 76 thou (0.076").
Go to your next location and repeat the steps.
There I am showing about 76 thou.
Next location.
Same thing ...
about 77 thousandths.
... and 77.5 thousandths (0.0775").
Take the average of your four measured locations
and if they fall into your can manufacturer's specs,
then you are good to go to the next step.
Once you have done your First Operation seam thickness
you can now move onto your final seam width measurement.
Measure your can the exact same way you did in your First Operation seam thickness
by just attaching it at the right angle
and the same pressure
and mark down your measurement.
If you notice in this first location,
we have one tick showing which indicates 25 thousandths plus the 20 on the outer barrel
which shows, if you add them, 25 + 20 = 45 thousandths (0.045").
Move to your second location.
We have 25 thousands plus 21 thou which indicates 46 thou (0.046").
Third location, shows 45 thou.
Fourth location shows 46 thou.
If you take the average of your four locations,
Ball specifies Operation Two seam thickness to be 44 ± 2 thousandths (0.044" ± 0.002").
These are your Vernier Calipers.
You'll use these to measure your can seam height,
your body hook and your cover hook.
This works a lot simpler than the can seam micrometer
as you'll never go past 100 thousandths (0.100").
Whatever the needle points to, add up your ticks and that's your number.
Here we have our final seamed can.
We'll take our Vernier calipers, making sure that we're always parallel with the can and
we're not on an awkward twist to get an improper reading.
Same as Op One and Op Two, you want to measure in four different spots.
So there, we are at 99 thousandths (0.099").
98 thousandths of an inch (0.098").
99 thou (0.099").
... and 98 thou (0.098").
Again this is a Ball can.
Ball asks for 98 ± 2 thou (0.098" ± 0.002") specification.
If you fall in spec, then you can continue to the teardown.
Once you have torn your can down,
you're left with your body hook
and your cover hook.
You'll need to grab you Vernier Calipers again,
grab your can and
do the exact same thing you did with your final can seam height.
Make sure to be parallel with the can,
not twisted or crooked in anyway.
You'll want to grab the body hook,
rotate your dial in until it likes to sit down and
there we're showing a reading of 67 thou (0.067").
Again this is a Ball can and
Ball specifies the body hook to be 65 ± 5 thou (0.065" ± 0.005).
Measure in four locations.
There is 65 thou (0.065").
66 thou (0.066").
Then you can move into your Cover Hook.
Ball specifies the Cover Hook to be a minimum of 60 ± 5 thou (0.060" ± 0.005").
Here you'll have to be very careful to make sure you're grabbing the cover hook,
being square on there and getting a good reading.
There we're showing 64 thou.
Again, measure in a few places and take the average.
There we're showing 65 thou.
There we're showing 64 thou.
... and 65 thou.
Once all these measurements have been found to be in spec,
you can now go on and can!