Cutting "square" holes in sheet metal?
 

Hi Jeff,

Does it really make a square hole with sharp corners or does it make a
square hole with slightly rounded corners like the one shown in the
figure on http://mathworld.wolfram.com/ReuleauxTriangle.html ?

Jerry

Jeff Wisnia wrote:
wrote:

How would I go about cutting small 1/4 inch square holes in 10 gauge
sheet sheet metal?



Well, I'm glad you aren't trying to cut *large* 1/4 inch square holes,
they're pretty difficult to do right.

But the small ones are easy, just get retro and pick up a 1/4" square
drill from:

WATTS BROS TOOL WORKS, INC.
760 AIRBRAKE AVE.
PO BOX 335
WILMERDING, PA. 15148
phone, 412-823-7877

The company is so retro themselves that I don't believe they are
bothered about not having a web presence yet, or if they have one it's
pretty well hidden.

For any folks who think I'm "smoking the drapes" about the square drill
thing, there's a photo description of a polygon drill at:

http://www.integerspin.co.uk/polygon.htm

IIRC these were the drills that made the carriage bolt what it is today.

Jeff (Ducking.....)

Cutting "square" holes in sheet metal?
 

How would I go about cutting small 1/4 inch square holes in 10 gauge
sheet sheet metal?

Cutting "square" holes in sheet metal?
 

How many and how accurate? For just a few, drill a hole and use a
triangular file. 10 ga is .134" IIRC, that will take a serious punch and
die set to do a series of them, about 3-1/2 tons of die pressure.

wrote:
How would I go about cutting small 1/4 inch square holes in 10 gauge
sheet sheet metal?

Cutting "square" holes in sheet metal?
 

wrote:
How would I go about cutting small 1/4 inch square holes in 10 gauge
sheet sheet metal?



Well, I'm glad you aren't trying to cut *large* 1/4 inch square holes,
they're pretty difficult to do right.

But the small ones are easy, just get retro and pick up a 1/4" square
drill from:

WATTS BROS TOOL WORKS, INC.
760 AIRBRAKE AVE.
PO BOX 335
WILMERDING, PA. 15148
phone, 412-823-7877

The company is so retro themselves that I don't believe they are
bothered about not having a web presence yet, or if they have one it's
pretty well hidden.

For any folks who think I'm "smoking the drapes" about the square drill
thing, there's a photo description of a polygon drill at:

http://www.integerspin.co.uk/polygon.htm

IIRC these were the drills that made the carriage bolt what it is today.

Jeff (Ducking.....)

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

Cutting "square" holes in sheet metal?
 

wrote in message
ups.com...
How would I go about cutting small 1/4 inch square holes in 10 gauge
sheet sheet metal?


Load a 12ga. with pieces of 1/4" key stock

Cutting "square" holes in sheet metal?
 

J Gold wrote:

Hi Jeff,

Does it really make a square hole with sharp corners or does it make a
square hole with slightly rounded corners like the one shown in the
figure on http://mathworld.wolfram.com/ReuleauxTriangle.html ?

That depends on your definitions of "sharp" and "slightly rounded,
Jerry. :-)

I did locate a Brit manfacturer of them:

http://tinyurl.com/8wh7h

And that page states:

**************************

QUALITY

Square holes are produced with corner radii. The tools could be made to
make the corners square but would have too short a life to justify their
use. Hexagon, octagon and other polygon holes have sharp corners. A
short stubby push broach can be used to clean out the square corners,
but would not normally be required.

*************************

So I guess they're not really "sharp", but probably good enough to be OK
for accepting things like carriage bolts or the kind of square tubing
used for "wrought iron" stair rails.

Jeff


--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

Cutting "square" holes in sheet metal?
 

A pyramidal broach? Ie, take a 1/4" sq. broach, taper it a little (might
need a grinding house to do this right), drill a 1/4 or 15/64 hole, and
broach away, proly doable on a BP or a drill press.

Greenfield makes a "knockout punch set" for electricians, where you drill a
3/8 or 1/2" starter hole, and thread the male/female halves of a threaded
ball-bearing punch set on either side, and ratchet out your desired pipe
opening--over 2" in many cases.
Maybe you can locate this style of punch for small square holes, altho you
are dealing w/ a substantial thickness for that dimension.

Very fine O/A might could do it also. You can get amazingly smooth cuts w/
O/A, esp. if you get the heat right, and it kind self-rounds the edges--if
you desire. Or it can leave them quite sharp. You'll need some kind of
fixturing guide, for height and dimension. Will take some practice, also.

The 12 ga shotgun suggestion may just be a good bet!
----------------------------
Mr. P.V.'d
formerly Droll Troll
wrote in message
ups.com...
How would I go about cutting small 1/4 inch square holes in 10 gauge
sheet sheet metal?

Cutting "square" holes in sheet metal?
 

http://www.makezine.com/extras/15.html


On 2 Nov 2005 09:12:18 -0800, wrote:

How would I go about cutting small 1/4 inch square holes in 10 gauge
sheet sheet metal?

Cutting "square" holes in sheet metal?
 

On Thu, 03 Nov, Nick Carter and Felice Luftschein wrote:
http://www.makezine.com/extras/15.html

And for those unaware, Make is just about the best single magazine *ever*.

Subscribe. You'll be happy you did.


--Donnie

--
Donnie Barnes http://www.donniebarnes.com 879. V.

Cutting "square" holes in sheet metal?
 

And duck you should, Jeff!

Bob Swinney
"Jeff Wisnia" wrote in message
...
wrote:
How would I go about cutting small 1/4 inch square holes in 10 gauge
sheet sheet metal?



Well, I'm glad you aren't trying to cut *large* 1/4 inch square holes,
they're pretty difficult to do right.

But the small ones are easy, just get retro and pick up a 1/4" square
drill from:

WATTS BROS TOOL WORKS, INC.
760 AIRBRAKE AVE.
PO BOX 335
WILMERDING, PA. 15148
phone, 412-823-7877

The company is so retro themselves that I don't believe they are bothered
about not having a web presence yet, or if they have one it's pretty well
hidden.

For any folks who think I'm "smoking the drapes" about the square drill
thing, there's a photo description of a polygon drill at:

http://www.integerspin.co.uk/polygon.htm

IIRC these were the drills that made the carriage bolt what it is today.

Jeff (Ducking.....)

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

Cutting "square" holes in sheet metal?
 

Thanx for the pointer to "Make" magazine. I subscribed.