How to make "speed holes" using dimple dies
Have you ever made a panel or a bracket for your hot rod, only to find out that it was flimsy and flapped in the wind? Here is a way to firm up those flimsy panels and brackets so that they hold solid and release the air that flows over them.
 How to make 'em
Start off by drilling a hole or series of holes in the panel or bracket that you want to make using a drill bit that fits the pilot hole of the dimpling die.
After the hole is drilled, insert the pilot bolt along with the male and female dies. Center out the die in the hole.
Using a breaker bar, start tightening down on the pilot bolt until it comes in contact with the panel (sheet metal). Spray some WD40 on the dies and threads of the bolt to ease the strain it causes on the metal.
After tightening down to an appropriate level, this is how it should turn out...
...a nice line of holes.
If you were making a bracket that required stiffening to make it ridged, this is what you would end up with after making a series of holes and using the dimpling dies. A ridged panel that would flow air through it, not hold air back.
 Here's another way to do 'em
1. Layout a sheet of metal with the center lines marked horizontal and vertical (spacing).
2. Fit the hole cutter on for the appropriate size of center that you would like through a pre-drilled hole (3/8 or 1/2 inch)
3. Tighten down on bolt using a pneumatic gun and wrench until die cuts through material.
4. Now that your centering hole is punched, follow that up with using a corresponding dimple die that is inserted into the hole.
5. Tighten the bolt up with the impact gun and Voila! a perfect tapered dimpled hole that is very ridged and strong, as well as good looking.
6. Flat sheet to dimple, as easy as 1...2....3.
 Where to get dimpling dies
- Check these guys out: Kar Tek
- Flared hole dies: Light Racing
- Sets of dies: Van Sant Enterprises, Inc.
For a set or individual dimpling dies or cut-out dies made of 1018 or 4140 heat treated dies, get a hold of Mosley Machine at 903-866-2006 and talk to Leah. Ask her for the best deal of the day. They make anything from 1/2" to 5 or 6 inches. Here's a link that shows you the product, http://www.pirate4x4.com/forum/showthread.php?t=841511 & this one, http://www.pirate4x4.com/forum/showthread.php?t=796323
 Or, make your own dies
A special thanks to Drewfus from the HAMB site for offering up the pictures for the homemade dies that are shown here.
We’ve all seen fancy dies, toss them a elaborate press, and off you go... unfortunately most don’t have that luxury. So, to create a cheap and easy method to get the flair, without breaking the bank, a 4” long piece of 2” solid bar was used; the following details will explain the basic process used to create the dies.
 The female die
First, drill a 10.8mm hole through the centre. In an effort to make 2 dies from the one bit of bar, a female taper was machined to both ends, the angle was approx. 30 degrees (from square to the centre line), with the O.D. of each taper being 46mm (for the 1 1/4” hole), and 33mm (for the 3/4” hole). A 1/2” UNC thread was then tapped through the centre (because that’s what was readily available, a UNF thread, or a larger bolt size would be better if available).
 The male die
From an off-cut of the 2” bar, a 1/2” hole was machined through the centre (to match the bolt), and a large chamfer was machined at approximately 15 degrees (any bigger of an angle and you will have difficulty in ‘nicely’ flaring the hole by hand.
 Where do you want to use 'em?
As you looked over the pictures that you seen here, more than likely your creative juices have started to flow on where you would use them. If making a bracket to hold up a piece of sheet metal under a fender, bend up an angle bracket or gusset plate and weld or bolt it in. With this idea of dimpling, now layout the bracket on sheet steel (satincoat or stainless). Using a circle template and black marking pen, draw a series of different sizes of holes on the sheet steel. Then find the center of each hole, center punch and drill an appropriate hole for the dimpling die (see note 1, below) and dimple the sheet steel. The dimple would not only make it more ridgid, but the flaring would add strength to the bracket. You would then bend up your bracket and weld or bolt it in. The bracket would let air flow through, wouldn't gather debris and would wash clean in the rain.
Could you also imagine using these dimple holes or oblong flared holes in your frame or panels to allow access to bolt-ons or accessories? Flared holes make good access holes to master cylinders that are located below floor panels and its easy to make covers for them too.
Note 1: An appropriate size for the centering hole for up to 1 inch dimple is 1/2 to 3/4 inches, for 1 to 2 inch dimple is 3/4 to 1 1/2 inch hole, and 2 - 3 inch is 1 3/4 to 2 1/4 inch hole. Hole punches make sharper and cleaner holes than hole saws.
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