# Making strip with a rolling mill

If you’ve used a rolling mill on round or square wire you will have
noticed that not only does it get thinner and longer, but it also
gets wider. If you could predict it, it would be a great way of
making thin strip.

The application at The rolling wire-strip calculator has moved

does this prediction. As long as your browser or smartphone has
Javascript, it should work. Although the app is web-based, the
calculations are done locally.

You input the width and thickness of the strip you want, and the app
calculates the size of the round or square wire you should start
with. Additionally, if you tell it the length you want, it will tell
you the length of the input wire.

Unless you are lucky, its unlikely that you already have wire of the
required input size, but its easy to make it from some that’s
thicker. Tell the program the thickness of what you have and it will
tell you how much you need in order to make required starting size.

Once you’ve got the starting size, roll it to the required width or
thickness in as few passes as possible.

A word of caution: unless you keep the wire at right angles to the
rolls it will produce a curved strip which is impossible to
straighten. I use parallel pliers against the rolls to hold it at a
slight tension.

The parallel pliers have a hollow hinge so the wire can go from the
jaws right through the hinge - the pliers and the wire are then at
right angles to the rolls. Since the pliers are much thicker than the
opening of the rolls, there is no possibility of them being caught.

Regards, Gary Wooding

Hello Gary,

Thanks for posting this!

Did you write this calculator yourself?

Thanks for throwing in the little tip about applying tension of the
wire as it feeds, this is essential! One of those simple little tricks
that makes such a huge difference!!

I had to learn this through trial and error before I got the magic
formula.

I recently have gotten into blacksmithing (almost a year now) and
the folks I have met so far share everything, most will not only tell
you about a technique but (if time and space allows) they will also
demo it for you as well…

This experience has been a polar opposite in regard to my
experiences with jewelry making, where most of the folks I have met
who fabricate guard their knowledge fiercely.

Anyway, apparently blacksmithing used to be like this not too long
ago, but the craft almost died so now people share it so the
knowledge will never be lost.

It is nice to see folks so willing to share jewelry making
knowledge, this way the craft of fabricating jewelry can live on!

Thank you again
Kenneth

I have been collecting this and writing it down in my
bench notebook for years. I still have to go back and look it up and
then guess most of the time. I have looked at your calculator and
can get results, but they don’t seem to be based on any specific
units. Can I assume metric and how to you represent the gauge of
thickness? Your suggestion on placing tension on the feed side of a
rolling mill is well noted.

Thanks. Rob
Rob and Sandy Meixner

What are the measurements in the Rolling wire-strip calculator in MM?

Jerry

``````I have been collecting this and writing it down in my
bench notebook for years. I still have to go back and look it up
and then guess most of the time. I have looked at your calculator
and can get results, but they don't seem to be based on any
specific units. Can I assume metric and how to you represent the
gauge of thickness? Your suggestion on placing tension on the feed
side of a rolling mill is well noted.
``````

I use millimetres myself, but you can use any actual units you like,
as long as they are consistent and you don’t mix them in the same

But you can’t use gauges. I never use gauges because there are so
many different ones. There are several different wire gauges, for
example, and nobody actually states what gauge system they are using.

Regards, Gary Wooding

This is a great tool, but from experience one thing to note is that
different rollers “spread” metal at different rates and the rate of
reduction will also affect how much it spreads. Looking over my
notes here some of the calculations are way off. For instance to get
a 5mm x 1mm rectangle profileI start with a 3.5mm square and that is
using a rolling mill with 150mm diameter rollers that spread the
metal much more than the smaller 100mm diameter rollers. If I was to
use the size recommended by the calculator the metal would end up
4mm x 1mm. Ben

``````This is a great tool, but from experience one thing to note is
that different rollers "spread" metal at different rates and the
rate of reduction will also affect how much it spreads. Looking
over my notes here some of the calculations are way off. For
instance to get a 5mm x 1mm rectangle profileI start with a 3.5mm
square and that is using a rolling mill with 150mm diameter rollers
that spread the metal much more than the smaller 100mm diameter
rollers. If I was to use the size recommended by the calculator the
metal would end up 4mm x 1mm. Ben
``````

Thanks for that Ben. I developed the calculator by
tabulating a series of experiments using my rolls that have 65mm
diameter rollers.