SAE 1144 Stressproof

Can somebody help me cross reference SAE 1144 Stressproof to a BS number. A stab in the dark puts me at EN9.

The people in the USA seem to like this steel for making crank shafts. I can understand why from what I can read up the steel is very stable even after heavy removal.

I need to make a crank for a USA model that is calling for SAE 1144 and would like to get something as close as posable to this spec to avoid the normal pit falls.

Said crank will be made from 50mm/2" sold and 250mm/10".

Cost is not the problem I'm just very unsure of my specs.

No idea of EN standards but shipping cost from the US of a small piece might be worthwhile.

From previous discussions about it I don't think there is am equivalent available in the UK.

I tend to use EN8 and if making a flat crank from round take a bit off one side, flip it over and a bit off the other and so on. Leave it 1mm or so oversize and let it sit for a week or two before final machining.

Doesn't the SAE 1144 steel have a bit more Manganese than EN8/9 and around 0.2% Sulphur so it is free-cutting? Similar to what we call 44SMn28.

Thor

See:

https://equivalentmaterials.com/materials/sae-1144

Basic 1144 cold drawn is not the same as 1144 Stressproof which has been stress relieved though composition is the same.

That is why it is liked for crankshafts as it does bot go banarnna shaped when you cut more off one side than the othe

Edited By JasonB on 22/03/2022 08:13:32

In the golden era "Take a piece of half shaft". Ahhh, those were the days.

Regards Ian.

Thank you all.

It seem this has been spoken about before and every body has found all the same results as me. Or should I say they have not found a replacement with in the UK.

US Shipping right now is just a joke for every £20 spent shipping is about £50 and as of right now I have 2 lost fly wheels in there system. The second one being the replacement for the first one. So my trust right now is a tad low.

EN8 was my last pick from my racing days we use to make every thing from EN16 old habits and all that. But I think having ago with EN8, EN9 and EN16 just to see how each one moves over time could be fun as most of the work will be CNC any way.

If you get black EN8 it's less likely to move than bright. I've used this guy on e-bay a few times.

What is the engine?

Postage from the US is certainly not cheap going by what I have paid for US made casting sets

Edited By JasonB on 22/03/2022 19:57:47

At work, we stress relieved steel part machined aircraft parts at 190C for 3 hours, in a fan oven, cooling naturally in air.

Edited By old mart on 22/03/2022 20:20:00