OneWay Posted February 5 Share Posted February 5 Good day all. I want/need to fabricate a hammer strut for my Automag III. These are notorious for bending the struts and are extremely hard to find replacements for nowadays. I was going to post a picture but the url would be to a commercial business so not doing that. It is a simple stem (.075) square on .075 sheet stock, with a flat spade about half it's length and a .125 hole in it- not much to its shape or fabrication. Can someone enlighten me as to a material that would be best to make it from to resist the stem bending and the hammer link pin wear? Needs to be tough and resistant. Heat treating with a torch will be a challenge as the "stem" is about 3 times smaller than the spade/hole end and difficult to uniformly heat-treat. The design bugaboo is where the stem meets and is the point of bending (failure). Thanks kindly, much appreciated Link to comment Share on other sites More sharing options...
80seriesaddict Posted February 6 Share Posted February 6 A guy on ARFCOM had some auto mag parts for sale. I’ll try to find you a link. Link to comment Share on other sites More sharing options...
80seriesaddict Posted February 6 Share Posted February 6 There ya go… hope a strut is in there. https://www.ar15.com/forums/ i read further… looks like your trying to make an upgraded part. Sorry to waste your time. Link to comment Share on other sites More sharing options...
Tampa-XD45 Posted February 6 Share Posted February 6 You might get more info here: https://www.amtguns.info/ Check Ebay. I see Automag parts listed there. Link to comment Share on other sites More sharing options...
OneWay Posted February 6 Author Share Posted February 6 18 hours ago, 80seriesaddict said: There ya go… hope a strut is in there. https://www.ar15.com/forums/ i read further… looks like your trying to make an upgraded part. Sorry to waste your time. Not a waste of time. Appreciate your input, THANKS Link to comment Share on other sites More sharing options...
OneWay Posted February 6 Author Share Posted February 6 3 hours ago, Tampa-XD45 said: You might get more info here: https://www.amtguns.info/ Check Ebay. I see Automag parts listed there. Thanks for the lead. I didn't initially post there as I had pretty well sifted through everything I could locate on the web search and dead-ended. I came here basically looking for some knowledge about types of steels, annealing, etc. It is a pretty straight forward piece and with the correct thickness of the proper material, it shouldn't be too hard of a project. Even laser cutting or EDM may be viable. After all AMT (apparently) did not do a particularly stellar job of manufacturing the part. The Automag III in .30 carbine is a great piece, but there were a couple things that engineers could have been done better. Link to comment Share on other sites More sharing options...
OneWay Posted February 7 Author Share Posted February 7 Would 4130 Chromoly survive as a hammer strut? Link to comment Share on other sites More sharing options...
Farmer Posted February 7 Share Posted February 7 (edited) It should a material that can be hardened similarly to the spring so the two can slide easily together without the spring digging in but something that doesn’t get brittle. I know on some of my guns where I’ve polished the struts that they are pretty hard but I think could be bent slightly if needed. You may be on the right track with a chrome moly as that’s what many springs are made of. The heat treatment will be the key but I think can be done fairly easily. I know Brownells has some stuff called I believe called Hard and Tuff (I’ll have to check) that you dip your part in before hardening it. It protects the surface from o2/oxidation and gives a hard surface hardness while leaving the center non brittle. I’ve used it on some die’s I’ve made and it works well. Edited February 7 by Farmer Added Link to comment Share on other sites More sharing options...
Toolguy Posted February 9 Share Posted February 9 I would make it out of S7 drill rod. Shock resistant tool steel. Harden to 62 Rockwell C and draw (temper) to around 40 Rc. Link to comment Share on other sites More sharing options...
OneWay Posted February 10 Author Share Posted February 10 FARMER- Thanks, Brownell's (used to be) a great source for materials but any more it is hit and miss ALONG with their higher prices they always had. Once I had some of their paste that resisted heating and still may have some Kasenit. They no longer list the paste (forget the name) but with it on the stem and Kasenit on the wider hole-end it could maybe work. Toolguy- Thanks also. If the S7 is indeed drill rod stock, I no longer possess a means of milling it uniformly flat. I am versed on an 'elbow-mill' that with a flat file could fabricate said part from proper flat stock. I'm going to post my inquiry on the AMT forum and see if anyone there can be of assistance on this particular problem. Thanks again all, MUCH APPRECIATED! Link to comment Share on other sites More sharing options...
Farmer Posted February 10 Share Posted February 10 @OneWay Think it was Heat Stop. I may even still have some. It was a light wet clay like material that really did absorb a lot of heat. Was similar to some of the stuff they use in furnace pots to protect the bricks. Link to comment Share on other sites More sharing options...
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