Small request

[Lognic04]

Hi all, :hi:
I'm making a mirror, which needs precise saggita measurements. I use coins under a steel ruler to gauge the depth, as i have no feeler gauges or a spherometer.
I'm wondering if someone would be kind enough to measure the precise thickness of a one and two dollar coin with calipers for taking measurements? (or more coins!)
I can then precisely check my saggita and also update the clearly wrong wikipedia article
Thanks!!! Hope someone can help! :thanx:

:thumbsup:

[billdan]

Here you go Logan this has all the details for you.

https://en.wikipedia.org/wiki/Coins_of_the_Australian_dollar


EDIT: Whoops your suggesting that wikipedia is wrong, sorry about that.

[eddiedunlop]

As requested, I obtained the following measurements (in mm):

$1: 2.6, 2.5, 2.55 mean 2.55

$2: 2.7, 2.75.2.65 mean 2.7

Measurements were taken from randomly selected positions on the coin rim. I did notice a bit of variation on individual coins.

[Lognic04]

Thanks Martin!
Seems like i have been overestimating the saggita a LOT!

[Saturnine]

Logan

If you have access to a set of metric drill bits in 0.5mm increments you can use them to slip under the steel rule edge to measure the sagita.
For arguments sake, if a 2.5mm has some play and a 3.00mm wont fit , then your sag. is somewhere in between, say 2.75mm. Theoretically you should then be able to measure to an 0.25mm accuracy, give or take a bit.

[bojan]

This (https://www.ebay.com.au/itm/AU-Digital-LCD-Depth-Gauge-Car-Tyre-Tire-Tread-Brake-Pad-Shoe-Pad-Wear-0-25mm/282495840826?hash=item41c610723a:g: Iy0AAOSwK6RZKRI6) is the tool for you.
Or this (https://www.ebay.com.au/itm/Car-Tire-Digital-Tread-Depth-Gauge-0-25-4mm-Measurer-Motorcycles-Tyre-Tester/222858778657?hash=item33e36b1821:g: lc0AAOSw7yZalVvG) one..

Or, if you prefer analogue.. this (https://www.ebay.com.au/itm/Test-Gage-Metric-0-10MM-Outer-Measuring-0-01mm-Accurate-Clock-Dial-Indicator/162602542127?epid=1964076473&hash=item25dbdde42f:g:f9QAAOSwOGlbY 7Fx).