开云体育

Speaking of Metric vs. English, I once worked with a machinist who HATED metric.? He said, "There are just too many places below the decimal."? What?? That's because at the time he was working on drawings for things designed in English but with all the dimensions converted to metric.? Of course, things designed natively in metric don't typically have that annoyance.

To swing it around to lathes, although not Unimat,? ALL of the Chinese mini-lathes are metric with 1mm pitch lead, cross feed, and compound screws whether they have metric or English marked collars.? (With the exception of Micro-Mark which has English 20 TPI thread screws yielding 0.050 inch per turn.).

Here is how they have "English" units on a lathe that is natively metric.? One turn of the handwheel is 1 mm or 0.0394 inches.? That's pretty close to 0.040 inches, so they just mark the wheel in 40 increments as being "close enough."? It seems that most buying these (amateurs and hobbyists) are not bothered as they tend to measure otherwise for the final cut otherwise or something.? Or spend most of their hobby trying to improve the lathe otherwise as an end in itself.? Or don't know.? Or don't care.

But it gets more nuanced than that.? I have seen some with 40 equal divisions marked.? And some with 39 equal divisions and then one smaller division.? That would be 39 divisions for 0.039 inches and one last smaller division for that remaining 0.0004 inches.? Arguably more honest, but still not helpful if trying to count a number of turns and come up with an accurate total in your head.? But usually, we don't count a lot of turns doing lathe work.? But we might on a mill.? And the mini-mill has the same issue (except for what Micro-Mark sells) and often you DO crank a lot of turns and need to know the actual change.

For those who want to change their metric machine masquerading as English, LittleMachineShop offers conversion kits to make your world right again.

And here's an odd duck.? A while back I bought an assortment of metric thread hex bolts from China, but they had English hex heads (like 3/8 inch).

Charles E. "Chuck" Kinzer