Atlas SPS Plus round bar

[michaelj123]

Hey there.

I quote on jobs for a steel machine shop in Canada.

I'm looking at a drawing that calls for Atlas SPS Plus round bar. Being diligent, I searched your forum history and found a post from 2003 where someone had found Atlas SPS on a drawing and had discovered it was manufactured by Atlas Alloys in Canada and is a very old designation that has fallen out of use. None of my suppliers know exactly what Atlas SPS Plus refers to, and I cannot find any literature online to point me in the right direction. Atlas Alloys Canada no longer exists.

My question is - what is the equivalent to Atlas SPS Plus round bar as called off by a blue print?

If it helps, these bars will be machined into pins used to build a collapsible miner canopy assembly.

Thank you in advance for your help!

 

[metman]

http://shopswarf.orconhosting.net.nz/steelequiv.html

This site shows Atlas SPS to be AISI 4140.

The Plus vesion could be different.

Design for RELIABILITY, manufacturability, and maintainability

 

[michaelj123]

Hi metman.

I've come across this equivalency chart in my hunt for answers. Unfortunately it doesn't specifically designate the "SPS Plus." I'm hoping someone has an old reference manual kicking around on their desk, or a physical properties spec for Atlas SPS Plus to compare to what's available now.

Thanks!

 

[btrueblood]

May be a trade-name or knock-off of "Stressproof Steel", which is Niagara's trademark designation for a cold-rolled AISI 1144 bar stock.

 

[redpicker]

Does the drawing refer to any mechanical property reqruiements?

I have a vague recolection from 30 years ago (or more) of Atlas Steel and that SPS Plus refered to a modified 4140 that was modiifed to allow increased mechanical properties. Similar to 4140H vs 4140. What is unclear is whether or not the SPS Plus referred to a proprietary set of mechancial properties, or only the chemistry.

I'll be watching this thread, as I am now curious.

rp

 

[michaelj123]

I'm looking at the drawing and it gives no indication at all to the physical nor chemical properties of the round bar. The only detail I have is "All round bar must be Atlas SPS Plus or equivalent."

The customer has chimed in on the drawing, stating that 4140 Annealed round bar will suffice for the job, but he nor his boss know if 4140 Annealed is equivalent to what is actually called off on the drawing.

While the problem is resolved on my end, I remain curious as to what is equivalent to Atlas SPS Plus.

 

[dbooker630]

My Woldman's book shows Atlas SPS has a composition of 0.40 C, 0.75 Mn, 0.60 Cr, 1.25 Ni, 0.15 Mo and balance Fe. I would say the above composition is more similar to the former standard 9840. My 5th edition book does not show an SPS Plus.