killforfood Posted January 11, 2011 Posted January 11, 2011 I'm going to purchase some raw materials for making rocket tooling and want your guys opinion on the best alloys. From what I've read, stainless is best for the spindle and rams seem to be predominately made from aluminum. I'm wondering what alloys would work best? I guess it's a balance between toughness and machinability. Also what stainless is non-sparking?
dagabu Posted January 11, 2011 Posted January 11, 2011 (edited) It really depends on what you are looking for. Stainless steel has the durability, aluminum is cheap, brass doesn't gall. There are problems with them all and each has their benefits as well. If you dont have a lathe or access to one, stay with aluminum, its easy to tool and its cheaper in case you screw it up. For aluminum, 7075 tools the best but is twice the price. 308 SST will not spark under the conditions we put it through and is the easiest to tool. If I had $100.00 to spend on materials, I would go 100% brass. Here are a couple on my recent endeavors, 5/8" spindles and 1/2" Universal Hybrid tooling. Edited January 11, 2011 by dagabu
Peret Posted January 11, 2011 Posted January 11, 2011 Online Metals have every kind of rod and tube, aluminum - brass - steel etc - and they don't mind selling you a foot length. It's interesting to compare prices. I don't remember brass being so expensive, but I suppose that's something to do with copper going up 40% last year.
dagabu Posted January 11, 2011 Posted January 11, 2011 If I may add to Peret's list of metal stores: -eBay-Discount Steel, which is onlinemetalstore.com and is different then onlinemetals.com-Speedymetals.com Personally, I go to Discount Steel's yard and rummage through their dumpsters (I get yelled at every time until I tell them what I am looking for and then they actually help me look) for cut odd pieces so I dont have to cut them to length. the ends are also painted to identify type and size which is really handy if you have a bucket full of scraps to sift through. On brass, the scrap price vs new is only about 20%, they are not making a 200% mark up on it but the aluminum runs $2.50 a pound as scrap and in 3" round, that makes the price difference about $50.00 per foot.
WSM Posted January 12, 2011 Posted January 12, 2011 I'm going to purchase some raw materials for making rocket tooling and want your guys opinion on the best alloys. From what I've read, stainless is best for the spindle and rams seem to be predominately made from aluminum. I'm wondering what alloys would work best? I guess it's a balance between toughness and machinability. Also what stainless is non-sparking? According to the US Government, 300 series stainless steel is non-magnetic, non-sparking. I've seen many spindles made from 303 stainless which is 'free cutting" due to the 1% lead in the alloy mixture. Most aluminum for rammers is aircraft grade, 6061-T651, but yellow brass is very nice if you can afford it. Have fun and show us your new tools when you get them made. WSM
killforfood Posted January 12, 2011 Author Posted January 12, 2011 For aluminum, 7075 tools the best but is twice the price. 308 SST will not spark under the conditions we put it through and is the easiest to tool. If I had $100.00 to spend on materials, I would go 100% brass. Here are a couple on my recent endeavors, 5/8" spindles and 1/2" Universal Hybrid tooling.Those spindles look nice all polished up. Are they stainless? My local vendor is Grainger I prefer to use them because I get a discount, no shipping charge if I do a will call and they are on the way home. Unfortunately they don't have ¾" rod in 7075 aluminum or 308 stainless. But they do sell the alloys that WSM mentioned (6061 and 303).I also have some local scrap yard may have some cheaper options.
dagabu Posted January 12, 2011 Posted January 12, 2011 Those spindles look nice all polished up. Are they stainless? My local vendor is Grainger I prefer to use them because I get a discount, no shipping charge if I do a will call and they are on the way home. Unfortunately they don't have ¾" rod in 7075 aluminum or 308 stainless. But they do sell the alloys that WSM mentioned (6061 and 303).I also have some local scrap yard may have some cheaper options. My apologies, it is indeed 303 (dyslexia) and 6061 (any series) aluminum is fine, it will all work.
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