[jdholbrook]

I've had my mill a few months and my lathe at least a month and I'm tired of having to convert fractions to decimal to decide what tool to cut what and what corner radius to use to suit my tools.

Why are we still with this archaic system?
If I didn't have to buy end mills in fractions I would go pure metric.

Time wasted!

[InMesh]

Many of us in other Countries wonder why the US still uses this and there is no reason any more for 345 /64 ths please stop .(VW polution is in Metric )...

[cmantunes]

I feel your pain. Customary units suck and need to be put to rest. I find myself memorizing a bunch of fractional inches in millimeters and avoid having to deal with the archaic system.

[mactec54]

I've had my mill a few months and my lathe at least a month and I'm tired of having to convert fractions to decimal to decide what tool to cut what and what corner radius to use to suit my tools.

Why are we still with this archaic system?
If I didn't have to buy end mills in fractions I would go pure metric.

Time wasted!

You must be new to the machining world, almost all suppliers sell metric or fraction size cutters in the USA, if your machine is CNC it does not matter whether you cutter is metric or fraction sizes, you just program to suit

[Kiwi]

...if your machine is CNC it does not matter whether you cutter is metric or fraction sizes, you just program to suit

I've seen vernier callipers based on 1/128 fraction but never heard of CNC programming done in fractions.

[mactec54]

I've seen vernier callipers based on 1/128 fraction but never heard of CNC programming done in fractions.

I thought you were smarter than that, you should do a study on your NZ history, your change to metric was not complete until 1976, it started in 1969, before that you used the English & American system, all numbers no matter what the number is, it breaks down from a fraction size to a Decimal number, the same for metric

When you are using a cnc, it does not care what size your cutter is it can be a fraction size 3/64 ( 0.469 ) or 3/32 (.0938 ) or metric size 1mm ( .0393 ) 5mm ( .1968 ) they all will do the same job, that's cut the part

I use both Metric & Inch it makes no difference to me, they are both just numbers, if you reground your cutters, you have all kind of sizes, you program to suit the cutter you are using

[jdholbrook]

MacTec54. The conversion chart drives my point home.
Wouldn't need that if everything was metric.
Hours saved converting this and that.. even if you're not mixing metric and imperial. Simply the fraction to decimal conversion.

Just ranting because I've wasted too much time on calculating the decimal equivalent of a fraction not to mention the mistakes I've made while converting.

[Kiwi]

I thought you were smarter than that, you should do a study on your NZ history, your change to metric was not complete until 1976, it started in 1969, before that you used the English & American system, all numbers no matter what the number is, it breaks down from a fraction size to a Decimal number, the same for metric..

Thank you for the conversion chart. I'm old enough to be familiar with the imperial and metric system.
The OP's problem is converting fraction format (eg 13/16) to the decimal format (0.8125) when programming as we all need to do.

[mactec54]

MacTec54. The conversion chart drives my point home.
Wouldn't need that if everything was metric.
Hours saved converting this and that.. even if you're not mixing metric and imperial. Simply the fraction to decimal conversion.

Just ranting because I've wasted too much time on calculating the decimal equivalent of a fraction not to mention the mistakes I've made while converting.

You have to think in Decimal numbers, no matter what you are using metric or inch system

You need to know just as much for metric use, as you can have multiple sizes in metric as well, check the chart, knowing the decimal equivalent of 1/16 1/8th & 1/4 sizes was basic 6 grade math

If you are wasting time doing number conversions, then just use metric, & you will see that you still have to do the same amount of work, the more you use either system you will get to know the Decimal equivalent of both Metric & Fractional sizes

When doing your designs, don't use oddball sizes, use what is easy for you to work with

There are many good free wall charts, & quick reference booklets, these can be helpful for learning & just for a quick glance to check your numbers

[bhurts]

This is a old tired argument. I learned metric so I wouldn't have to fight with understanding measurements I was not familiar with. I was told starting in grade school that we were leaving the inch/fraction system behind and moving to metric. The only difference is now we sell inch and metric versions of every tool. I love the inch/fraction system and always will prefer it. I am equally as compatible with the metric system and don't complain about having to convert. Don't be afraid of numbers because like mactec said there all interchangeable if you stop complaining long enough to do some simple math. I know all my fractions and mm in decimal format by heart with no need for a chart. It means I'm more productive and less stressed. I've never posted anywhere that metric is stupid or counterintuitive even when I was thinking that was the case. A us fractional tape measure will always be more intuitive then it's metric equivalent. The numbers are easy to visualize when estimating with your eyes. I may not like metric as much but I'm glad I learned it. It has helped me expand my horizons. I'm just sick of hearing it's what we use so you should have to to. That's the kind of neo Nazi thinking that has dragged this world down so many times. It also tries to imply that if it makes since to me it should to you to without acknowledging that taking that stand has always stifels progress and knowledge.

Ben

[ger21]

I'm in a similar situation to Ben.
In the woodworking world, everything is in fractional inches, but most modern hardware uses metric sized holes and spacing, so I use both.
Fractions are just decimal numbers written differently. Learn the decimal equivalents and it's painless to switch from fractions, decimal inches and metric.

[elfrench]

If your CAM program is like mine, it has tool tables with a comment field for each tool. Just enter the metric, decimal, and fractional values for each tool. Sort the table by size makes it trivial to select the right bit.

[cmantunes]

One just needs to read Wikipedia's "Inch" History section to realize that this unit has no place in a technologically advanced civilization. The only saving grace for the inch nowadays is that it was eventually redefined in terms of metric units as 25.4mm.

[bhurts]

One has only to read the headers over each graph to know that the writer has no place in a technologically advanced society.

Ben