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What are the most common drill letter sizes used in woodworking?.Is there a standard chart or reference guide for drill letter sizes?.How do I determine what size drill letter to use for a specific task?.
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It takes me about 5-10 minutes each and it’s well worth the savings. Now I’m ready to tackle my whole pile of used orifices and get them ready to be re-used. I had no problems drilling the new holes and the brass plug doesn’t look like its going anywhere. Although the holes might look close, the newer (shiny) one is actually much smaller than the original. Below is a picture of one of the original orifices and one of the rebuilt and redrilled ones. Then it was ready to re-drill with a smaller hole that I needed for LP gas. Once that was done I used my belt sander with a fine grit belt to clean up and flatten the end of the orifice. The rod also expands in the middle and completely seals the orifice on the top and inside.
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The two ends of the brass rod are pressed out like the head of a nail by the force. This works just like a brass rivet to create a solid plug. The using a hammer I tapped and then with a little more force, smashed the little piece of rod into place. Then standing the orifice up on end so the threads are face up and the orifice hole (now plugged) is facing down towards the anvil, I placed a flat punch down into the orifice from the top. Make sure the flattened size is on the outside. I put one of the little pieces of rod into the hole of one of the orifices. Now I went over to my vise which has a small anvil on it. I then used a pair of pliers to hold each piece of rod and touch it to a fine belt sander to flatten the end (get rid of the angled cutting marks). I then used a pair of wire cutters to cut about 1/4 inch pieces of the rod – one for each orifice I was fixing. While it spun around I cleaned it with some 600 grit sandpaper I had. The brazing rod was a little oxidized so I cut a piece about two inches long, put it into my drill press. Step 2 – Clean Up and Cut the Brazing Rod I then put a small countersink bit (or you could just use a larger drill bit), on the top of each orifice to create a bevel to the hole opening in the top. So, I put the number 42 drill bit into my drill press and proceeded to drill each orifice with an even bigger hole than it had before. I then played around and found that a number 42 drill bit was just about the right size for the rod. In my shop I found some 3/32 inch brass brazing rod which I decided to use as a filler or plug. Step 1 – Drill Out the OrificesĪll of the orifices I have are made of brass. That being said, I am very pleased with my results and love it that I was able to finish my project that night and save a bunch of money in the process. If you choose to take this information and do something – anything with it, you are on your own. I am publishing this for information only, not as a guide for others to do it. It probably goes against everything a good gas guy learned at school. This process is not something that you should do. At the same time I am giving you my caveat: Now yes, I was able to pull it off and I’ll explain it here in detail. That’s when the thought occurred to me – maybe those natural gas orifices could be rebuilt with what I had laying around. I could go online and probably find them but I’d loose about a week waiting for them and it would cost me between four and ten dollars each. But the ones I had all had huge natural gas holes in them. It was a great design and I knew the orifices existed because I had a bunch of them. I had a simple design that used orifices with a male thread on them which would screw directly into the manifold. So, I was rebuilding a smoker oven late one Friday night. Since most of my work is with propane, these old natural gas orifices are mostly worthless – or are they? Natural gas orifices have much larger jet holes in them than propane orifices. The problem is that most of these were used for natural gas. I also have a larger box of used orifices that I have pulled from a wide variety of old used equipment over the years. If the hole get’s too big there is not turning back to make it smaller – or is there? When I’m building something I use these and drill the hole out to the size I want. I have purchased a small stock of standard orifices with the smallest hole possible in them. Also they have a cool BTU cross calculator that is really useful. Convert a Natural Gas Orifice for use with PropaneĠ5-2019 Update: Shout-out to Anderson & Forrester who took the time to write me with some great info! Take a look at their website at: Specifically look at page 19 of their catalog for a kit to resize your orifices.