PDA

View Full Version : Making a simple die



Tony Ennis
08-22-2011, 07:56 PM
I want to make a number of brass pieces that look like blunt nails. The shaft would be 1/16" in dia, the head 1/8" in dia.

My idea was to make a die (if that's the right word) by drilling a 1/16 hole in some steel perhaps 3/8" deep, then centered on that hole, a 1/8" hole about 1/16" deep. These holes would be made with an endmill so they'd be flat-bottomed.

The idea is to put a brass rod in the hole and whack it with a hammer to mash the brass into the 1/8" part.

The die would have to have 2 parts so I could push the part out from the bottom.

So, what's the right way to do this?

Evan
08-22-2011, 08:50 PM
It doubt it will work well. In order to have enough material to fill the volume of the head the 1/16 material will have to project 3/16" from the top of the 1/16 hole. Based on much experience driving rivets that is too far and the wire will most likely "dump" instead of forming a head. Dump means to fold over. Rule of thumb is 2 times diameter at most. Also, the brass will have to be dead soft.

Mike Burdick
08-22-2011, 09:36 PM
Tony,

I have made brass rivets roughly in the shape you describe with 1/8" welding rod but not with the 1/16" you desire. Mine were round headed.

Here's how I did it...

I made a "dimple" in the side of a piece of steel for my form tool - this dimple was in the shape of the head I wanted on the brass. I placed this "form tool" in the holder on the lathe.

I chucked up a piece of ordinary brass welding rod in the lathe and let it stick out about 1/2". To form the head, I ran the lathe at a medium speed while using the carriage to push the form tool into the end of the brass. I guess this would be considered a form of spinning.

Once one gets the "technique" worked out, rivets can be made very quickly!
.

Black_Moons
08-22-2011, 09:37 PM
Considered casting? Brass melts at a reasonabley low tempature compaired to steel/etc...

HWooldridge
08-22-2011, 10:12 PM
You are describing an upsetting die. Put a blunt point on the struck end to center the impact and use a heavy hammer, maybe 2 lbs. As Evan said, dead soft annealed stock is best. You can either put an ejector pin in the bottom or make left and right halves then clamp them together with a Kantwist c-clamp. You could spend time making leader pins to align the blocks or just use the brass stock.

Tony Ennis
08-22-2011, 10:24 PM
I'm making a spring-loaded pin, not a rivet, by the way.

The good news is that the head of this thing has two purposes:
1. form a platform against which a spring will push, and
2. prevent the pin from falling out of a hole.

The head will not be visible.

So if it dumps to some extent, it would not be the end of the world though of course we all like perfection.

I'd need about 200 of these pins.

(we'll talk about the tiny springs on the next thread, though we've been over spring-making several times...)

Tony Ennis
08-22-2011, 10:27 PM
...and the size of the pin is relatively arbitrary. As long as the pin won't fall out, it doesn't have to be 1/16". it could be 3/32", or whatever. The 1/8" diameter value is a harder number - I am space constrained.

CCWKen
08-22-2011, 11:05 PM
I've made some custom brass rivets using the same method. The only difference is that my "die" was the length I needed with the hole all the way through. I then set that die on a flat plate. After the head was formed, I just punched the rivet loose from the bottom of the die. I'm just glad I only had to make 10 or so. ;)

By the way, I used a rivet set and air riveter to form the head so that went quick and head looked factory formed. It took longer to punch the rivet out of the die than to make it. A little oil helps, just don't over do it. It will blow out! :eek:

huntinguy
08-22-2011, 11:12 PM
http://www.matoska.com/cgibin/gencat.cgi?AC=genitems&IL=1010-100-014

looks like they are available from a craft supply store. If they will work.

I am sure you could find them locally.

Evan
08-22-2011, 11:19 PM
As long as the pin won't fall out, it doesn't have to be 1/16". it could be 3/32", or whatever. The 1/8" diameter value is a harder number - I am space constrained.

Adjust the parameters of wire gauge and head thickness until the unfilled volume of the head equals a length of wire no greater than 2 times the diameter of the wire and it will work fine. Using 3/32 will probably do it. You do the math this time. :D

JoeCB
08-22-2011, 11:23 PM
Check the boat building supply house Jamestown Distributors for copper and bronze nails

http://www.jamestowndistributors.com/userportal/search_subCategory.do?categoryName=Nails,%20Tacks, %20Brads%20and%20Escutcheon%20Pins&category=481&refine=1&page=GRID

Joe B

rdfeil
08-22-2011, 11:49 PM
+1 on JoeCBs idea

A small brass nail or tack would come close to your description except the head would be thinner

yf
08-23-2011, 02:09 AM
Sounds like a brass "tinners" rivet would do.
I don't know if they come that long.

If making them yourself, you can get away with more than the 2x stickout by heating the wire with a torch in the left hand and a heavy hammer in the right hand.
One blow ought to be enough for 1/16" brass.

Make the block thick as the finished length with multiple holes. Place it on your anvil, heat one wire, hammer it, repeat, then cool the whole thing, turn over and punch out the finished parts, tumble them to clean up the discoloration from heating.

CCWKen
08-23-2011, 03:18 AM
You can heat brass to anneal it but I wouldn't work it hot. It will crack, split or break. Brass needs to be worked cold. Heat to red and cool between heavy working. It can air cool or fast cool (dip), it doesn't matter-It won't heat treat. I wouldn't bother if all you're doing is forming a head.

Ian B
08-23-2011, 08:53 AM
How about going the other way - start with 1/8" dia rod, make a mini bar peeler and machine the 1/16" portion. The tool would look something like a normal threading die with 3 or 4 cutting edges, only with a smooth bore.

It's a tiny amount of metal you're removing. Highest spindle speed you have, hold the bar peeler in a tailstock die holder, hand feed it to a preset stop, part off with a small parting tool in the toolpost.

Ian

Richard Wilson
08-23-2011, 01:53 PM
Does it have to be brass? would copper do? I've done the same job quite successfully starting with copper rivets, and deforming the dome head into the flat recess. It overcomes the issue Evan raised about the projecting length being too great to succesfully rivet down. Of course, if you can find brass rivets, then thats the complete solution. Starting with dome head rivets means you don't need a 2 piece die either, because the preformed head stops the piece sliding down the hole, you just turn the die over and punch it out from the back.

Richard