high strength/impact resistant shafts

[BillClark]

I will apologize for my ignorance in advance.
I am interested in locating a high strength, high impact tolerant, shaft material 8-10mm in diameter, preferably precision ground to fit bearing. This will be used in a fixture to conduct destructive testing.
test example-
-8mm shaft
-about 6" in length
-4" of this shaft will be supported (mounted)but not rigid (will have damping to allow it to obsorbe energy somewhat)
-about 2" of the shaft will have to deal with the bulk of the forces
-a 27" long plastic object with a weight of 100g (cg midway) will swing from one side (imbalance) and be slowly accelerated to 1500+rpm. If that goes well another object will be placed (from a remote location) in the path of the 27" plastic object
-shaft can bend if overloaded but can not break
-flexibility over rigidity would be a plus
-must be able to machine small hole in one end of shaft material
-largest safety factor for shaft preferred

the component that attaches the object to the shaft is what is being tested as well as the shaft itself. I realize there is much detail missing and will try to furnish if I can. This will be a "worst case scenario" for the tested component/shaft. Hy Tuff, AMS6418 popped in my head although that material appears to cater more toward fatigue resistance. I really need some help, please

 

[MikeHalloran]

When you say precision ground shafting, I think "Stressproof G/P". As opposed to regular Stressproof, which you have to buy way oversize. It may or may not be appropriate; it sounds like you have almost enough numbers to work out the kinetics of the situation, and from that estimate the stress levels encountered.



Mike Halloran
Pembroke Pines, FL, USA

 

[CoryPad]

Unless you are working on a safety-critical application, I wouldn't look at Hy-Tuf steel (cost, availability). I think a hardened and tempered steel shaft (e.g. SAE 4140) is likely to meet any needs you have for this application.

 

[TVP]

I think availability of 8 mm precision ground stock is going to be the limitation, and therefore I agree with CoryPad that you should probably start with a more common grade like 4140. Grades like 4340 and Hy-Tuf tend to be available only as large diameter hot-rolled bars.

 

[unclesyd]

You might want to give these people a call for metric sizes.

http://metricmetal.com/products/round.htm