reconbob Posted May 28 Report Share Posted May 28 (edited) Does anyone know what grade/alloy of steel was used for M1918 and M1918A2 BAR receivers? I know that later the A2 receivers were machined malleable iron castings, and also some were fabricated using "Armasteel" but I am looking for the original steel alloy. The BAR receivers I have tested were not hardened anywhere at all. Plus the gun was first designed and manufactured (1918) before alloy steels (4130, 4140, 8620, etc.) existed. The bolt supports are quite hard, but they were probably case hardened back then, and they are separate parts riveted into the receiver. Any help is appreciated. Bob Edited May 28 by reconbob Link to comment Share on other sites More sharing options...
StrangeRanger Posted May 28 Report Share Posted May 28 FWIW Armasteel was a GM trade name for nodular iron, a specialized form of malleable iron. It's probably as strong as the non alloy steel in the original receivers but it's chief virtue other than massively reducing manufacturing cost is that it works very well with cyclic loadings without work hardening/embrittling. It's widely used for automotive crankshafts and conn rods for that reason Link to comment Share on other sites More sharing options...
damifino Posted May 29 Report Share Posted May 29 (edited) I'll try again Edited May 29 by damifino Link to comment Share on other sites More sharing options...
StrangeRanger Posted May 29 Report Share Posted May 29 1050 steel is heat treatable up to a max Rc58 which is pretty hard. I'm surprised they used 1050 rather than more easily machined 1045 if they weren't going to take advantage of its higher hardenability Link to comment Share on other sites More sharing options...
damifino Posted May 29 Report Share Posted May 29 (edited) 68 coupe, if there is not enough detail. I can try and email it to you. If you are on Weapons Guild, I put the complete set in their library. Edited May 31 by damifino corrected spelling Link to comment Share on other sites More sharing options...
reconbob Posted May 31 Author Report Share Posted May 31 Thank you for the info! Bob Link to comment Share on other sites More sharing options...
RoscoeTurner Posted May 31 Report Share Posted May 31 From some sources I have gathered that Armasteel was not used in the initial production of NESA receivers. What I have trying to track down is the approximate time that NESA switched to Armasteel? Link to comment Share on other sites More sharing options...
damifino Posted May 31 Report Share Posted May 31 From Wiki. Production rates greatly increased in 1943, after IBM introduced a method of casting BAR receivers from a new type of malleable iron developed by the Saginaw division of General Motors, called ArmaSteel.[28]After it successfully passed a series of tests at Springfield Armory, the Chief of Ordnance instructed other BAR receiver manufacturers to change over from steel to ArmaSteel castings for this part.[28] During the Korean War M1918A2 production was resumed, this time contracted to the Royal McBee Typewriter Co., which produced an additional 61,000 M1918A2s.[29] Link to comment Share on other sites More sharing options...
RoscoeTurner Posted May 31 Report Share Posted May 31 56 minutes ago, damifino said: From Wiki. Production rates greatly increased in 1943, after IBM introduced a method of casting BAR receivers from a new type of malleable iron developed by the Saginaw division of General Motors, called ArmaSteel.[28]After it successfully passed a series of tests at Springfield Armory, the Chief of Ordnance instructed other BAR receiver manufacturers to change over from steel to ArmaSteel castings for this part.[28] During the Korean War M1918A2 production was resumed, this time contracted to the Royal McBee Typewriter Co., which produced an additional 61,000 M1918A2s.[29] Thanks, the NESA BAR I own was one of the first 1100 produced by NESA if the assigned serial number block 500,000-750,000 is correct. I always thought it would be steel rather Armasteel due to its early production date in 1943 but was curious about what year they actually switched materials. Link to comment Share on other sites More sharing options...
damifino Posted June 1 Report Share Posted June 1 (edited) You can see the difference in the cast and machined trigger housings. Even after machining the Arma Steel casting has a grainier, even pitted, surface finish than the smooth surface of steel. Is your gun parked or blued? The steel ones I've seen were blued. If parked it would have been sand blasted and harder to tell. Maybe that will help. Also found this interesting. http://www.90thidpg.us/Equipment/Articles/BARStocks2/index.html Edited June 1 by damifino Added text Link to comment Share on other sites More sharing options...
damifino Posted June 7 Report Share Posted June 7 Here is the link to the BAR prints in the Internet Archive. Free to download. https://archive.org/details/M1918BrowningAutomaticRifleBlueprints/page/n1/mode/2up They are a great library and an asset to all of us. If you like the prints, think about donating to keep this stuff available. (If this is not allowed, please delete) Link to comment Share on other sites More sharing options...
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