Should I learn Metric now? Beginning woodworker help.

[Jon Steffen]

I would say i'm a beginner of "fine woodworking", but i've been building stuff for 20 years. Gazeebo Eagle Scout project, deer stands, garage storage, fences, car ports, remove load bearing wall.....

I'm in Wisconsin USA and learned on the imperial system, but i'm wondering if I should start measuring things and using tools in Metric.

Any of you Americans make the switch and wish you did sooner?

Any not so obvious reasons why I should not and just stick to Imperial?

Is Metric more accurate or precise?

[Jamie Buxton]

There's one more possibility: decimal inches. You get to use the decimal system, which is way better than fractions. And you get to use inches, which you and your suppliers both understand.

American machinists have been using decimal inches since the eighteenth century. That's why we have things like 45 and 22 caliber bullets -- that's .45" and .22".

[Jon Steffen]

There's one more possibility: decimal inches. You get to use the decimal system, which is way better than fractions. And you get to use inches, which you and your suppliers both understand.

American machinists have been using decimal inches since the eighteenth century. That's why we have things like 45 and 22 caliber bullets -- that's .45" and .22".

didn't know about that.
i'll have to see if incra, or the table saw I might get has rulers like that. Maybe wixey has a digital fence that also does inch-decimel. I feel like they would.

[David Bassett]

Plenty of outstanding work done in both systems. I don't think learning metric would hurt you in anyway either. (I.e. become "bilingual".)

That said woodworking generally doesn't need high precision, just like parts matching with high accuracy. How you achieve this depends how you are working. E.g: Neander's will scribe lines from part or space to the next stock to be cut. A power tool user will learn to set the table saw fence and cut all like parts without moving it. (Derek Cohen extensive posts documenting his builds where you can see this in practice. He does a lot of handwork, but also uses power tools. Plus he works in metric and it's never interfered with understanding what he's doing.)

I'd guess, working in the US, you'll end up choosing inches & fractions because so many of our supplies are imperial and marked that way.

[Curt Harms]

I'd guess, working in the US, you'll end up choosing inches & fractions because so many of our supplies are imperial and marked that way.

I think that's the biggest reason to use inches and fractions. If I lived in a country that had been metric my entire life I'm sure I'd find Imperial measurements odd and foreign. As mentioned, calculations are far simpler in metric than inches and fractions.

[Jim Becker]

I'd guess, working in the US, you'll end up choosing inches & fractions because so many of our supplies are imperial and marked that way.

The thing is...a lot of what we buy in materials are metric underneath, but remarked in inches for the convenience of the retail trade. Plywood is a very good example. It's been metric for a very long time. Screws and bolts in much of the products we buy are metric. Etc. As I noted above...we're sitting in the middle with both systems currently overlaying each other.

[Jamie Buxton]

The thing is...a lot of what we buy in materials are metric underneath, but remarked in inches for the convenience of the retail trade. Plywood is a very good example. It's been metric for a very long time....

The "three quarter inch" plywood I get is pretty consistently .72" thick. That's 18.3mm. I'd say it is unclear whether it is metric or imperial. (My guess is that it is 3/4", with all the tolerance taken to the shy side.) And the "quarter inch" plywood now runs .21" or so. That's 5.3mm. Again, not obvious what the underlying system is.

[Rod Sheridan]

I believe the plywood standards specify standard metric dimensions such as 19, 12, 6 etc which are then sanded...Rod

[Jim Matthews]

I measure parts off each other, to assure best fit.

Any measuring system that uses a tape measure, yard (or meter) stick or laser range finder is subject to transposition errors.

Marking pieces in place reduces such errors.

I favor a marking knife and double square for layout.

[Bob Jones 5443]

I reach my limit with inches when I run into the need to take half of 23-11/16. Then I tend to convert using the calculator on my phone and maybe convert back to inches if need be.

Also, when I'm checking the extension of a plane iron from an Eclipse jig, I use mm.

[Warren Wilson]

It’s odd. As a old Canadian I was born in the British Imperial system with inches and gallons and bushels and pecks, but everything has been meters and litres and kilometres for many decades and I have adapted in some areas and not in others. The metric system just makes sense any time you are calculating. Gas mileage, for instance, ratios, conversions. But I have continued to use inches for woodworking because for the most part it is measurement rather than calculation and I’m mentally lazy. Though if I have to divide 2’ 7 7/16” into thirds, I’d reach for my metric measuring tape!

It doesn’t have to be an either-or. It’s trivial to just use another scale — maybe even fun to try: but maybe not buy the Starrett rules until you’re sure.

[Frank Martin]

I grew up with the metric system. When I started woodworking (about 18 yrs ago) I pretty much had to use the imperial system because table saw fence and some of the other common scales were all imperial. Now I use a euro combo machine that has both scales. If I had not already invested into the imperial system, I would certainly switch to metric. May still do one day.

[David Bassett]

I reach my limit with inches when I run into the need to take half of 23-11/16....

Dividing in half is one thing that works pretty well with fractional inches. (23-11/16 / 2 = 11-16/32 + 11/32 = 11-27/32.)

Try dividing something into thirds. (Get the calculator out, convert to decimal inches, divide, and then try to find a fractional inch equivalent that isn't ridiculous, or...)

Use the "old fashioned" way: get the dividers out, step it off, and don't worry about what the value is!

[Josh Molaver]

When I started woodworking about 10 years ago I made the decision to go metric (having grown up in the US / imperial) - took a little getting used to but I am glad I did l, and can convert back and forth and work in either system now.

[roger wiegand]

Grew up in Imperial, went into science and learned about metric, concluded that we were insane for not having adopted it back in 1790. I lived with a mixed shop for a long time and just last year went through and did the full metric conversion-- mostly involving putting new sticky-back tapes where needed and buying a couple more rules and measuring tapes (the 5.5 m tapes from Tajima are great!) I still have a few things that I won't replace, like a good set of inch Forstner bits. and lots of stuff where it doesn't matter.

The one thing to avoid at all costs is doing conversions. That will kill your accuracy and drive you crazy. Just learn what a centimeter looks like and think in those terms. It's awkward at first and then becomes second nature. It does tend to drive my wife crazy when we're cooking because I can eyeball 500 g of flour or 100 g of butter to within a couple percent but can't for the life of me tell her how many cups or furlongs or whatever that might be.