The choice of metric or imperial tool sizes.

[Andy Kev.]

I was wondering what the best strategies are for dealing with the choice between metric and imperial systems. The obvious answer is to plump for one or the other. However, I got a set of imperial chisels, which I suppose doesn't matter because if you are going to cut a mortise it seems to me that you just have to pick a chisel which looks the right size, irrespective of what it actually measures or is measured in. On the other hand if you come up against hardware, then I reckon that dictates what you must use e.g. if the only screws available are metric then you have to have metric bits. Then again my auger bits are imperial.

Because I didn't encounter metric until secondary school my instinct is still to think in feet and inches. To me the big advantage of imperial is that notions like half, quarter, eigth etc. are perfectly natural (even Europeans talk about halves and quarters in daily life). To do metric I have to stop, get a ruler and see what e.g. 25 cm actually looks like.

So, has anybody got any suggestions which are better than my current approach?

 

[t8hants]

Unless you are fitting machine parts together I don't think it would matter that much. The wood doesn't know or care what system you use, but as you are based in Germany I would presume finished stock comes in metric. If you are preparing your own material from the rough then you can par off to imperial if you wish.

G

 

[RogerP]

I'm in my 70's so grew up and was taught imperial but in my later days worked in a school where it was all metric.

These days I use either or both, sometimes mixed and sometimes neither (story rod)

 

[wizard]

Imperial! Most of my machines are whitworth

 

[Spindle]

Hi

I use and have both but my advice to you would be metric - better resale value :wink:

Regards Mick

 

[Cheshirechappie]

I think it depends what you're doing. If you intend to make large numbers of interchangeable components for batch production of many items, absolut measurements matter. If you're making one-offs where each component is cut and trimmed to fit others, absolute measurements are neither here nor there, so it follows that tools could be imperial or metric with equal facility.

Suppose you're making a small coffee table. The tenons on the rails will be cut and trimmed to fit the mortices in the legs, which will be about a third the thickness of the rails, give or take a bit. If the rails are about 3/4" thick, mortices of 1/4" or 6mm would do equally well. If the rails are 20mm thick - well, ditto. If the legs finish 7/8" square or 22mm square matters not a jot.

Also worth bearing in mind is many sizes of woodworking tools - especially vintage ones - are quite 'nominal' anyway. Put a micrometer to a selection of 1/2" firmer chisels, and they'd vary from just over 7/16" to just under 9/16". Modern ones are a bit nearer the mark, but still not dead to size in engineering terms. Your 1/4" chisel might turn out to be nearer 6mm anyway. Doesn't matter a jot - it still cuts wood accurately enough.

 

[JohnPW]

I would choose one system and stick to it. If you use metric, on old tools, just measure its actual size in mm and work from there.

 

[Woodchips2]

I was brought up with imperial so now have both imperial and metric tools and measuring devices. Some days I measure in imperial and cut in metric and sometimes vice versa so often have stock cut too small or too long

As much as I say "metric will never catch on" I would stick to metric, I can't think we would ever revert to imperial even if we came out of the Common Market :lol:

Regards Keith

ps wonder if Nigel Farage drinks pints or litres when he's in Brussels :roll:

 

[AndyT]

Picking up on your question of metric screws, I don't think they will mind whether your pilot holes are 1/8" or 3mm. :wink:

 

[bugbear]

On the other hand if you come up against hardware, then I reckon that dictates what you must use e.g. if the only screws available are metric then you have to have metric bits.

The fits of scsrew to wood varies with the hardness of the wood anyway, and is not an exact science.

I mainly use a 3mm bit to pilot #8 screws in hardwood!

BugBear

 

[Andy Kev.]

Those are interesting replies.

With respect to what AndyT and Bugbear say: maybe I'll scribble some notes as a reminder for where the differences are so small that it doesn't matter.

Mick's point about resale values would never have occurred to me but as I have no intention of selling any kit, I don't suppose it will effect me.

I suspect that in general terms where I must use measurements, I'll probably end up defaulting to imperial (because of the chisels) and because I have a feel for them and will use metric where I must. Perhaps the most valuable tool in this area is my 12" steel ruler which has also got cm marked on it.

 

[bugbear]

With respect to what AndyT and Bugbear say: maybe I'll scribble some notes as a reminder for where the differences are so small that it doesn't matter.

I think you've misunderstood me - pilot holes for screws vary sufficiently with wood type that you just need
need the right size, regardless of wether the screws are imperial or metric or wether your bits are imperial
or metric. You're NOT matching the bit to the screw precisely. You're matching the bit to the required
pilot hole, which varies (strongly) with wood type and screw length, so as long as you
have a range of finely gradated bits, it's doesn't matter wether they're imperial, metric,
or picas and points.

BugBear