Shaft material for bronze bushing

[JGary]

I am looking for a source or recommendations for shaft materials to use with bronze (copper/tin - low graphite) bushing that is oiled impregnated in a low speed light load application? Currently using TGP 303 Stainless and experiencing problems.

 

[metengr]

You have a wide range of shaft materials to choose from depending on your specific application, namely environment and strength requirements.

What exactly is your problem with the 303 SS, and what is your specific application? The answer to these questions can help to provide a proper recommendation for shaft material.

 

[JGary]

The 303 SS is apparently gauling and scoring which creates an oily residue that binds the shaft and bushing. The shaft lasts only 4 to 6 months of a 6-hour day 5 days a week.

The application is an idler roller shaft approx. 13.19" long and roll diameter of .813. The shaft Diameter is .3145. There are bronze bushings on both ends of the shaft held down by a small compression spring (2.5 in/lb.) The surface speed of the roller is 15 IPS.

The idler roller is used in combination with a driven roller to transport single sheets of paper through a device that scans and images the document. Typically in an office environment.

 

[metengr]

You have several options – a low alloy steel or a martensitic stainless steel. I would probably use an AISI Type 410 stainless steel to fabricate the idler roller shaft. The 410 SS should be supplied in a quenched and tempered heat treatment condition (about 28 Hrc in hardness) for optimum results. This heat treatment will provide increased resistance to galling and allow the 410 SS shaft to be easily machined for an excellent surface finish.

 

[JGary]

Thanks for the information. We will give the 410 SS a try.

 

[EdStainless]

410 is a good option. Make sure that it is Quenched and tempered, and don't let them substitute 416. This is the free machining version and it will not have as good of a surface finish.
The ends can be ground to a nice finish and should run well.

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Corrosion never sleeps, but it can be managed.

http://www.trenttube.com/Trent/tech_form.htm

 

[Tmoose]

What is the PV rating of the applicatioin and bearings?

The bearings need good alignment and both the journals need to be concentric to prevent edge-loading, which can turn a light load into a heavy load.

Journals need to be round and smooth (~10 microinch), and maybe even directionally polished to get the best results.
Some fancy assembly lube can perform absolute miracles getting thru the break-in period.