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Shot blasting to a SA-2-1/2 surface

1. We are going to Shot Blast a Mild Steel Plate <7mm Thickness (surface) with S-330 Steel Shots ,Hardness of Shots is 45~50 HRC, the surface hardness of MS Surface is around <30 HRC.Blast wheel Speed 2800RPM .Shot Blasting machine is mechanical.

Question = What would be the impact (indentation)I.e Roughness Value, of steel shots
S-330 on this surface after shot blasting ? what is the method and measurement indentation on surface after shot blasting ? Can we use the same size High Carbon Cut wire shots (conditioned) on this surface ? Generally what is the indentation value of s-330 on normal shot blasting on Mild steel surface with Hardness <30HRC?

Ashish Saraswat
plasting shop - Delhi, India
November 20, 2008

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Hi, Ashish. I think you would need to get a copy of the spec from the Swedish Institute for Standards to determine if the media you intend to use complies with the spec or not.

I believe it's actually "Sa.2.5" rather than "SA-2-1/2", but I don't think you'll find any published correlation between blasting standards and depths of indentation at various hardnesses, but maybe you will.

Please see letter 12526 for more complete explanations.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
September 3, 2009