DiAcro shear advice please

I am considering buying an older 12" DiAcro guillotine shear. Will
it cut 26 gauge into a bezel strip without making it curl away from
the cut like what happens when I use a non-guillotine bench shear or
snips? The machine is not nearby so I cannot test it. Thought I’d
check with you all before Ibuy it.

Thanks for your help (from a long-time lurker).

in Missoula, MT

Hi Nancy,

The 12 inch diacro shear is an awesome tool for making flat square
straight cuts off a piece of sheet metal. It will need to be equipped
with the factory hold down clamp that pins the sheet to the table
while doing its job though; the clamp is spring loaded and moves up
and down as you move the cutting handle and allows the easy
adjustment of a metal to be cut in relation to the blade. The
adjustable rear guide is also great for setting up repeated straight
cuts on sheet metal for production work (after you adjust the stops
to make the desired cut it can be repeated until the entire sheet is
reduced to the size strip you want). The blade thickness on the shear
does limit the narrowness of the strip cut: the back stop gauge can
only be adjusted until it touches the upper shear blade. The blade
is 6mm thick. If you want narrower strips you have to eye ball each
cut. IF you need to make repeated shearing straight cuts in sheet
metal with little distortion then this tool just may be what you
need. It comes at a used cost on ebay of between 1600 and 800 bucks
depending on condition and accessories like the back gauge or hold
down clamp.

Having said my piece about the quality of diacro sheetmetal shears
there is another thing that catches my eye about your question
regarding this equipment; you wish to shear bezel stock without
distortion. This is only one way to make bezel stock. You could
simply purchase coiled slit stock from a manufacturer / metals
supplier. The continuous strip of slit stock coiled up actually
reduces waste and or end cuts that will need to be reprocessed. ALSO
the cost of the shear(1600 to 800 dollars) is comparable to the cost
of a good rolling mill. To produce bezel stock with a mill you only
need roll down the appropriate sheet, bar stock or round wire to the
desired gauge of bezel strip, anneal your metal along the way. I
strongly believe that if you do not already have a quality rolling
mill like a durston or a dinkel in your studio you would be far
better off spending your hard earned tool money on a mill rather than
a shear. I use my mill every day, I use my diacro shear once a week.
I purchased a duston c mill with combination rollers and half round
side rollers when I got out of college.

That mill baring a fire or natural disaster will outlast me. I only
regret that I didn’t go whole hog and buy the biggest hand mill they
had at the time the c mill was what I could afford.

Michael Edwards
Flying M Designs

Hi Nancy,

I’ve currently got a 12" DiAcro shear, and they’reworth their weight
in gold. Seriously, if it’s under $1000, and it’s in decent shape,
just get it. It’ll be the last bench shear you ever buy. Much
tougher and more rigid than anything made today for under $1500.

I’ve had a couple of the 6" DiAcro shears previously. Very nice
machines as well.

If the blade is sharp, and the gap is set right, you should have no
trouble with shearing bezel. It will curl down a little, but nothing
like the sort of ‘snail’ curl you get off of hand shears.

The blades can be resharpened reasonably easily by any decent tool &
cutter grinding shop.

The only real issue you may have is that the gap may be set too
wide. Cut some 24-26 gauge silver. If the edge of the cut burrs down
into the cut, the gap is probably set too wide.

(Steel needs a wider gap than silver, and heavier gauges need wider
gaps as well. Since the thing probably came out of a steel fab shop,
it’s probably set for heavy(ish) steel. Thus.)

You’ll need feeler gauges to get down in-between the blades (when
they’re down) to figure out what the current gap is. I can’t really
advise you on what’s “right"because it depends on what you’re
cutting, and I haven’t ever had to fuss with any of my DiAcros. But
the first step (if that’s an issue) is to figure out where you are,
and then try to figure out where you need to be. Don’t let the
blades actually touch, or grind past each other. I’d guess.002
or.003” would be the minimum gap I’d feel comfortable with. If you
really have trouble, I’ll go gauge mine, and let you know what it
is. Don’t go into it assuming it’s a problem. It may well not be.

I’ve bought 3 of them over the years, and never needed to change
anything. Do look at the blades to see if they’re nicked, (fixible)
or if they’ve got a chunk out of them. (replace) The ruler for the
’right angle’ guide may be out of square, or missing. No big deal
either way. Easily fixed. The safety clamp may be missing, which may
or may not concern you.

It gets in the way, and makes it really hard to see where
you’recutting. On the other hand, it does clamp the metal to the bed
during the cut, keeping it from slipping around, which is a good
thing. I took mine off, but it’s a personal preference thing, unless
the OSHA guys see it. Also it may (or may not) have the back fence
for setting depth on repeat cuts.

Not a critical thing for a jeweler, but nice to have.

Hope this helps