A friend just asked me how I might go about making 1 1/4" dia. round
holes in the bottoms of tin cans. He was thinking of making a chassis
punch to do the job. He needed an excuse to do something on his South
Bend Lathe.
I suggested making a "Dinker Die", as an easy to do, faster
alternative. I googled "dinker die" to get a .jpg to send him, and
didn't get many hits. This surprised me. I thought everyone knew about
them, but apparently not.
So, here's what I wrote him on the subject (use tool steel if you
want it to last):

Yuh know, us blacksmiths chisel cut sheet steel up to 1/16" thick or
more, cold, with a sharp cold chisel. I have several dozen of these
that I have made. I have a set of them that are curved, so I can
produce radii from about 1/4" to about 2".
You could also turn a "dinker die" in your metal lathe. It's just
a piece of tubing (water pipe, etc.) whose ID is correct for the hole
size. Then you turn a chamfer on the outside of the tubing at about 60
degrees. all the way towards the ID until it is sharp. Just set the
sharp end on the tin, backed with wood, and hit it. You simply punch
out a slug.
I have made many of these over the years. Sometimes its the hole
that I want and sometimes its the slug.
----------------------------
These work great for punching holes in rubber, leather, canvas, etc., too.


Pete Stanaitis

I've seen sets of these available as gasket hole cutters, Pete. Some
versions have holes in the wall of the tube section for inserting a tool for
ejecting the slug.

I've seen the tapered cut (to form the cutting edge) on the inside too,
making the OD the desired hole size.
I don't actually recall the term/name Dinker though, just remember them as
being referred to as hole cutters or cutting punches.

The forming of the sharp edge starts as a chamfer, but ends up being a
bevel, technically speaking.

From back in my early days as a pup, I would use nails for punches, and
sometimes still do. The point is ground or filed away, leaving a flat end
with a sharp edge.
Using the endgrain of a hardwood block as a backer, tapping the nail/pin
thru the sheetmetal, leather, rubber etc, produces a fairly clean hole with
little distortion in the sheet.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"spaco" wrote in message
...
A friend just asked me how I might go about making 1 1/4" dia. round holes
in the bottoms of tin cans. He was thinking of making a chassis punch to
do the job. He needed an excuse to do something on his South Bend Lathe.
I suggested making a "Dinker Die", as an easy to do, faster
alternative. I googled "dinker die" to get a .jpg to send him, and
didn't get many hits. This surprised me. I thought everyone knew about
them, but apparently not.
So, here's what I wrote him on the subject (use tool steel if you want
it to last):

Yuh know, us blacksmiths chisel cut sheet steel up to 1/16" thick or
more, cold, with a sharp cold chisel. I have several dozen of these that
I have made. I have a set of them that are curved, so I can produce
radii from about 1/4" to about 2".
You could also turn a "dinker die" in your metal lathe. It's just a
piece of tubing (water pipe, etc.) whose ID is correct for the hole size.
Then you turn a chamfer on the outside of the tubing at about 60 degrees.
all the way towards the ID until it is sharp. Just set the sharp end on
the tin, backed with wood, and hit it. You simply punch out a slug.
I have made many of these over the years. Sometimes its the hole that
I want and sometimes its the slug.
----------------------------
These work great for punching holes in rubber, leather, canvas, etc., too.


Pete Stanaitis

In article , spaco wrote:
A friend just asked me how I might go about making 1 1/4" dia. round
holes in the bottoms of tin cans. He was thinking of making a chassis
punch to do the job. He needed an excuse to do something on his South
Bend Lathe.
I suggested making a "Dinker Die", as an easy to do, faster
alternative. I googled "dinker die" to get a .jpg to send him, and
didn't get many hits. This surprised me. I thought everyone knew about
them, but apparently not.
So, here's what I wrote him on the subject (use tool steel if you
want it to last):

Yuh know, us blacksmiths chisel cut sheet steel up to 1/16" thick or
more, cold, with a sharp cold chisel. I have several dozen of these
that I have made. I have a set of them that are curved, so I can
produce radii from about 1/4" to about 2".
You could also turn a "dinker die" in your metal lathe. It's just
a piece of tubing (water pipe, etc.) whose ID is correct for the hole
size. Then you turn a chamfer on the outside of the tubing at about 60
degrees. all the way towards the ID until it is sharp. Just set the
sharp end on the tin, backed with wood, and hit it. You simply punch
out a slug.
I have made many of these over the years. Sometimes its the hole
that I want and sometimes its the slug.

Unless you want the slug, my favorite approach to making holes in thin
sheet stock is a step drill. They will make a nice clean round hole, an
with care, you can even debur the top edge. They are far safer than
twist drills, and you don't get trilobular holes. For a large hole in
thin material, you can use a step drill to make a smaller hole & use a
chassis punch like a Greenlee.

For tin cans, even the Chinese step drills would probably work. For more
serious stuff, McMaster sells TiN coated ones.

Doug White

spaco wrote:
Yuh know, us blacksmiths chisel cut sheet steel up to 1/16" thick or
more, cold, with a sharp cold chisel. I have several dozen of these
that I have made. I have a set of them that are curved, so I can
produce radii from about 1/4" to about 2".
You could also turn a "dinker die" in your metal lathe. It's just
a piece of tubing (water pipe, etc.) whose ID is correct for the hole
size. Then you turn a chamfer on the outside of the tubing at about
60 degrees. all the way towards the ID until it is sharp. Just set
the sharp end on the tin, backed with wood, and hit it. You simply
punch out a slug.
I have made many of these over the years. Sometimes its the hole
that I want and sometimes its the slug.
----------------------------
These work great for punching holes in rubber, leather, canvas, etc.,
too.

This sounds useful.
How much metal distortion is there? And what is the biggest hole you ever
made this way? Did you have to heat-treat the sharp end?

--
Michael Koblic,
Campbell River, BC

We use all 5 sizes of import specials from Horrible Freight in lab
classes on 24ga galvanized and 16 ga aluminum all the time. The largest
HF goes to 1-3/8"
http://www.harborfreight.com/cpi/cta...emnumber=91616
http://www.harborfreight.com/cpi/cta...emnumber=96275
One of my students was running them on 1/4" steel without too much issue.

MUCH safer for thin metals (no lift, no great tendency to grab and spin)

Michael Koblic wrote:
spaco wrote:
Yuh know, us blacksmiths chisel cut sheet steel up to 1/16" thick or
more, cold, with a sharp cold chisel. I have several dozen of these
that I have made. I have a set of them that are curved, so I can
produce radii from about 1/4" to about 2".
You could also turn a "dinker die" in your metal lathe. It's just
a piece of tubing (water pipe, etc.) whose ID is correct for the hole
size. Then you turn a chamfer on the outside of the tubing at about
60 degrees. all the way towards the ID until it is sharp. Just set
the sharp end on the tin, backed with wood, and hit it. You simply
punch out a slug.
I have made many of these over the years. Sometimes its the hole
that I want and sometimes its the slug.
----------------------------
These work great for punching holes in rubber, leather, canvas, etc.,
too.

This sounds useful.
How much metal distortion is there? And what is the biggest hole you ever
made this way? Did you have to heat-treat the sharp end?

On Dec 9, 1:53*pm, spaco wrote:
These work great for punching holes in rubber, leather, canvas, etc., too..

Pete Stanaitis

See: "Arch Punch"

Regards,

Robin

On Tue, 9 Dec 2008 18:19:27 -0800, "Michael Koblic"
wrote:

spaco wrote:
Yuh know, us blacksmiths chisel cut sheet steel up to 1/16" thick or
more, cold, with a sharp cold chisel. I have several dozen of these
that I have made. I have a set of them that are curved, so I can
produce radii from about 1/4" to about 2".
You could also turn a "dinker die" in your metal lathe. It's just
a piece of tubing (water pipe, etc.) whose ID is correct for the hole
size. Then you turn a chamfer on the outside of the tubing at about
60 degrees. all the way towards the ID until it is sharp. Just set
the sharp end on the tin, backed with wood, and hit it. You simply
punch out a slug.
I have made many of these over the years. Sometimes its the hole
that I want and sometimes its the slug.
----------------------------
These work great for punching holes in rubber, leather, canvas, etc.,
too.

This sounds useful.
How much metal distortion is there? And what is the biggest hole you ever
made this way? Did you have to heat-treat the sharp end?

Amount of distortion depends on thickness of material being punched
and what is used for a backing. I get very clean holes in thin
metal, rubber, leather, gasket mat'l etc using a hardwood backing
block.

No need to heat-treat for very small number of uses. For more holes
I've case-hardened with Kasenite. Honing the edge after hardening can
help a lot with soft resiliant materials.

This also works well in a vise or hydraulic press, sometimes easier to
get precise location if that's an issue.

Been making and using such things as one-offs for decades but I'd
never heard the term "dinker die", thanks to Spaco for that.