Oxy-Propane Curtting: Pressures

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I've had a Smith oxy-propane cutting torch for maybe a year. Since I don't find the need to cut often, I'm not an expert at it by any means. However,  I have been able to make some nice cuts with it when the need arises.For tips I have an SC40-0, SC40-1, SC40-2 and an SC40-3. Recently I had need to cut 1" plate with it. At the time it had the SC40-1 tip on it so I just decided to use that. I ran the propane pressure up to 30 or 35 pounds and the oxygen up to 50 pounds or so. It made an amazingly nice cut as in beautiful. Very little slag on the bottom side and very smooth on the cut itself.Later I looked up the chart in the Smith catalog and found that I should have been using an SC40-2 with a propane pressure of 10 and an oxygen pressure of 41 at the tank.With that experience in mind, I have several questions. How much fudging around should you do? I know with acetylene  I wouldn't want to be bumping pressure up over 15, but with propane I can't think of any safety concerns. I made a beautiful cut. Is that all that matters or are there other considerations?I notice that on all the charts for the 40 series tips it shows a propane pressure of 10 no matter the tip or the metal thickness. Is there danger associated with going over 10?I also notice that for the SC40 series tips, there is no setting for cutting less than 1/4" steel. Can I do a decent job running down to 5-7 pounds on the propane or do I need a different series of tips?Thanks.
Reply:The oxygen does the cutting, not the propane, so there really is no reason for a high fuel gas pressure, just like the references you stated indicate.-Tim
Reply:Thanks. That makes sense. As far as cutting stuff that is less than 1/4" thick, what is the recommended process for that? None of the charts that I can find in the Smith Catalog show any settings for less than 1/4". In my experience if you have a torch set for cutting thicker metal than you're actually cutting, you make a mess. Do I just set the oxygen pressure lower to do thinner stuff or are there different tips available or...?Finally, where do you obtain tip charts other than the catalog? The Smith site has a video on the homepage. All it shows is how to set a neutral flame, but at the end of the video they show tip charts and I have not been able to find a place to obtain those. I would think you could just download them in PDF format from somewhere and print them off but I have not seen them. Thanks.
Reply:There probably isn't any danger in over pressure but its wasting fuel. On my Oxy-Pro, I usually have the propane down in the 5-7psi range while running 21-25psi on the oxygen. 80% of what I cut is less than 3/8".Its all about fuel cost.