What does milgrain size refer to?

Milgrains are numbered 1 thru 15 in the catalog I’m looking at. Says
for example #12 is 1.2mm.

What exactly does that dimension refer to? If #12 is used for 1.2mm
thickness edge, that’s pretty darned big. Yeah, my cheap side is
showing I don’t want to buy the whole bunch of them.

What exactly does that dimension refer to? If #12 is used for
1.2mm thickness edge, that's pretty darned big. Yeah, my cheap side
is showing I don't want to buy the whole bunch of them. 

Personally, I’d say it’s safer to just consider the numbers as
arbitrary size labels, not relating to a given and useful
measurement. Among other things, sizing of the tools from one to
another, or one shipment to another, isn’t all that consistent. And
the thickness of the edge you’d use a millegrain tool on depends some
on how you want it to look. On some pieces, the long line that goes
down each side of a line of grains when the tool is narrower than
the edge, or the edge not a sharp enough ridge, can be a detail some
people like, since it defines the line of the millegrain more. On
other pieces, that line is mostly a scar, a toolmark to be avoided.

The sizes you’ll need depend on the work you do. In the pieces I
make for my employer, most everything is done with #8 millegrains. A
few with a 6, and some with a larger 12. The 12 is hard to use on
harder metals when hand driven. Even driven with a power handpiece it
can take several passes to get a decently full impression instead of
just the train track crosshatch markings…

By the way, if you do get in the habit of driving millegrain tools
around with a power handpiece (Lindsay or GRS), you’ll find the
little axle pins on which the tool wheels spin are pretty soft steel
that doesn’t last long. They bend, shear, and otherwise quickly fail
when driven by an impact handpiece. If you have a laser welder
though, you can easily fix them. I do this with new tools, just so I
don’t have to do it later. lightly sand the sides of the tip, taking
down the rivited over ends of the pins until you can drive the pins
out. Replace it with a suitable length of the shank of a high speed
drill bit. I think it’s the #76 bit that’s the right size, but I
could be wrong, so check that measurement. Since the drill bit is way
too hard to rivet over, you use the laser to weld the ends of the
drill bit back to the side holes of the millgrain tool. With that
hardened axle pin, the tools will wear out as they’re supposed to,
ie the impression wheel will get worn and dinged, rather than the
axle pins shearing off. You probably don’t need to do this for
millegrain tools used the normal way, ie by hand, and for smaller
sized tools, that works better anyway. But the power handpieces do
make it very easy to steer the tools around tight curves consistantly
if needed, and they help getting a fully formed impression if you’re
working with both a larger size tool and a hard metal, like some of
the white golds.

Peter

Milgrains are numbered 1 thru 15 in the catalog I'm looking at.
Says for example #12 is 1.2mm. 

I like size 6. 12 is huge!

Stanley Bright
Owner
A&M Jewelers

If #12 is used for 1.2mm thickness edge, that's pretty darned big.
Yeah, my cheap side is showing I don't want to buy the whole bunch
of them. 

Neil, that’s pretty cheap ;} Yes, the size is the millimeter width.
For old-fashioned bead setting with a millgrain edge I’d suggest a
#6 if you only get one. #12 is more towards the edge of a ring,
though the rings you buy are lathe done with lathe tools that are
even bigger than that. I use 4, 6 and 8 most of the time for the
usual jobs - have a #15 for the occasional thing.

The sized are to correspond sizes of gravers. For the best results
use #2 with graver #2; #4 with graver #4; and etc.
#2 - 0.2 mm
#4 - 0.4 mm
#1.2 - 1.2 mm

Leonid Surpin
www.studioarete.com

millgrains are the number of lines in a mm that you can apply with
the varoius tooling heads. Just roll them onto the sheet, or flat
/sizing stock and you have a millgrain edge. They are sold in sets
and can be ordered individually fromWholesale Tools in a large range
of sizes.Most jewelry supply vendors carry standard sizes as are
applied to wedding bands, etc…rer

Neil, that's pretty cheap ;} Yes, the size is the millimeter
width. 

Ok I compromised on cheapskatedness, I bought every other one
listed. Measured em too. MM width does not correspond to the number
although catalog says it does.

The sized are to correspond sizes of gravers. For the best results
use #2 with graver #2 

A graver would cut a groove, these are female wheels which leave
raised beads on a rib of metal. I don’t understand what you mean
here, Leonid.

Personally, I'd say it's safer to just consider the numbers as
arbitrary size labels 

Yeah, I think that’s it.

A graver would cut a groove, these are female wheels which leave
raised beads on a rib of metal. I don't understand what you mean
here, Leonid. 

I use milligrain in the following way. If I have to apply it on the
edge, I cut a grove next to the edge. The grove is necessary to clear
the edge of the wheel so the business part of the wheel can go to
work. It happens to be that the best results are achieved when
milligrain #2 is used with graver #2 an so on… Here is why:

The #2 graver will cut the groove corresponding the of the virtual (
created by spheroid depressions ) groove on milligrain wheel of the
same number.

That mean that angles of inclination of 2 planes forming the grooves
are the same. That brings both surfaces into the full contact and
enable creation of fully formed grains. Used away from the edge, I
cut
grooves on both sides creating a ridge.

Leonid Surpin