jack620 24th January 2013, 01:41 PM I am building two 0.8cc diesel engines and the plans call for "StressProof" steel to be used for the crankshaft. StressProof is a brand name of an American (I think) steel company. I believe 1144 is the nearest "number" steel to StressProof, but I can't find it in Oz. Interloy and Bohler don't carry it. Nothing on eBay. Does anyone know who might stock this in Australia? If not, I think I will substitute 4140.
Chris
Ropetangler 27th January 2013, 10:43 AM I am building two 0.8cc diesel engines and the plans call for "StressProof" steel to be used for the crankshaft. StressProof is a brand name of an American (I think) steel company. I believe 1144 is the nearest "number" steel to StressProof, but I can't find it in Oz. Interloy and Bohler don't carry it. Nothing on eBay. Does anyone know who might stock this in Australia? If not, I think I will substitute 4140.
Chris
G'Day Chris, Since no-one else has replied, I'll have a go. Now while I have read quite q bit, I have next to no experience of machining, so I may be well off beam, but hopefully if so, then some of the more experienced members will chime in. While 4140 would certainly have the required strength, it may be considerably more difficult to machine, (depending on what machines you have at your disposal) than something like 1045 which should be readily available, and is not that far away from 1144 in spec. 1045 is used for trailer axles and other similar applications, and you may well pick up a scrap piece from a local engineering company. If you would like, I will send you some pages from Machinery's Handbook, with the data for these and other alloys closely related, or you could PM some of the other more experienced members such as Machtool, BT or PDW, - I'm sure they would put you on the right track. Anyway all the best with your project,
Rob
Anorak Bob 27th January 2013, 11:59 AM We were all sitting back waiting for you to reply Rob.:U
This is about the most enlightening information I can find on 1144 - Metal and Metallurgy engineering - 1144 Stressproof (http://www.eng-tips.com/viewthread.cfm?qid=21337)
I have used 1045 and 4140 but I bumble along. Chris needs the advice of those better versed in the machining of these steels. There are a number of blokes out there who could comment, you've named two.
BT
aametalmaster 27th January 2013, 12:15 PM Went by the Stressproof plant not long ago outside Chicago Il. I have some on hand and it machines great...Bob
Niagara Lasalle Steel Products - Stressproof ®, ASTM A311, Cold Rolled Steel 1144 Round Rod (http://www.niagaralasalle.com/product-stressproof.html)
Ueee 27th January 2013, 12:26 PM What size do you need Chris?
Most of my experience is with spring steels, but i think any of the medium carbon steels would be fine.
.RC. 27th January 2013, 12:30 PM The 11 means it is a free machining steel.
44 is the carbon content... 0.44%
I guess the steel was chosen because it is free machining and thus leaves a nice surface finish...
jack620 27th January 2013, 05:33 PM Thanks Fellas,
The genuine "StressProof" is drawn then stress relieved in a furnace. I think the 1144 has a similar composition, but it hasn't been stress relieved. It's probably an overkill for a 0.8cc motor, but that's what the plans call for. I do know that 12L14 isn't acceptable. I'll have a look at 1045.
Since my original post I have been in contact with Niagara Lasalle. They don't have an agent in Oz, but they are prepared to send me some 3/4" bar. I just have to see if postage isn't prohibitive.
Rob,
I have a Hercus 260. I have done a little bit of machining of 4140. It's tough stuff, but I reckon I can machine it with a cobalt HSS tool in my DTH. I already have a copy of Machinery's Handbook, but thanks for the offer.
BT & Bob,
thanks for the links.
Ewan,
The crankshaft is 15.8mm at the flywheel.
Cheers,
Chris
Ropetangler 27th January 2013, 10:26 PM Well Chris if nothing else, I flushed out some of the usual suspects to impart their wisdom.:wink: O.K. on your having your own copy of M.H. a very handy reference to be sure, if only they split it into 2 volumes, it would be much easier to handle.
I did find this mob in the U.S.
LOT OF 1" HEX 1144 CRS STEEL BARS RAW MATERIAL MACHINE METAL KRC | eBay (http://www.ebay.com.au/itm/LOT-OF-1-HEX-1144-CRS-STEEL-BARS-RAW-MATERIAL-MACHINE-METAL-KRC-/251096553511?pt=LH_DefaultDomain_0&hash=item3a76855827)
who are selling bar ends of 1144 cold worked hex bar, but the postage is a bit steep, unless they can just send you a couple of bars rather than the 10 they have in each lot, and perhaps it would be cheaper to post. Unless they have gone up recently, the flat rate boxes were about U.S.$50, not the $63.45 they are quoting, - perhaps they have a handling charge as well. This is still not "Stressproof", although it may be another manufacturers take on it perhaps. The 1045 may not be the best choice of locally available material, it probably depends on which particular characteristics of SP1144 made the designer choose it above other types. It should be readily obtainable though. On the other hand, if you can handle 4140, it is very strong and tough, and can be made more so with heat treatment and nitriding if you can access those processes.
Thanks for the cheeky compliment BT, but somehow I doubt it,:U and Your expertise is well matched to your modesty.
Rob
jack620 28th January 2013, 09:51 AM Thanks for the eBay link Rob. That may be an option if they will break the lot down. A small 4lb USPS box was $16.95 last time I got one.
jack620 28th January 2013, 09:58 AM USPS have upped their prices. $60 for a medium (20lb) box and $24 for a small (4lb) box.
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