Home Forums General Discussion Shot Peening Process, Intensity, Coverage SAE AMS-S-13165 / Peening thin tubing

OkeyDoke,

I'm fairly convinced that shotpeening is a good way to petenticallt increase the strength of our frames, whether they be 7005 Series Aluminium, 3/2.5 Titanium or Micro-Alloyed Steel.

However, I'm pretty sure that if I approach a local peener, they well never have peened a high end custom bicycle frame before, so if I decide to take the plunge, I need to know what to ask for an what to expect.

Now, the spec I've been told to adhere to is SAE AMS-S-13165. My question is, does this spec have provisions for peening a tubular structure, often with wall thicknesses less the 0.035" (.889mm) in Titanium and down to .500mm for steel?

What information/knowledge should I have in hand before I approach a local shotpeener?

Can anyone recommend a firm in San Francisco that would be the best people to approach?

Finally, what would you expect the typical cost to be to shotpeen a high end bicycle frame?

OkeyDoke,

For sure peening is a good way to increase the fatigue life, am not sure however that it could be really beneficial for your application ($ vs improvement).

Anyway, to answer your questions, AMS-S-13165 will not recommand peening Titanium or Steel section under 0.09" thicknesses. For aluminium, it is suggested to use an intensity of .004 to .008 N using glass bead or ceramic shot.

If you wanna approach local shotpeener you need to tell them what intensity u need and the coverage desired (100% is standard).

I think Metal improvement might have a facility in San Francisco or around and they have been doing it for a long time.

Well you might wanna be extra careful on how the part will be peen if you wanna avoid deformation. Manual and wheel machine might cause more deformation than robotic peening, but robotic peening might be too expensive. Like I said before am not sure that it would be beneficial for your application.

Just out of curiosity let me know the outcome of the test if you run some!

I just though about it, but you could also used flapper peening with Mil-R-81841 spec.

This spec call for an intensity of 0.003 - 0.006 A for steel and titanium part, but nothing on Aluminum. Depending on your frame geometry, you might not be able to reach all area and cause more harm than good!