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Rave About Your Rack Please do not post retail SPAM.

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Kong vs Black Diamond 6-Dec-2006 At 1:58:39 PM Sceptic

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3 Sigma is a statistical analysis term. Strictly speaking it means 3 standard deviations. According to the BD website they use this to indicate their given break strength ratings are 3 standard deviations less than the average break strength they get in testing. In effect they are saying they discount their rating or use a safety factor. Is this something special? No, it is standard practice. Most reputable manufacturers do it & it's so commonplace they don't waste breath or ink talking about it. So what does 3 Sigma mean in the context comparing nuts? Probably nothing. 1/ Because nuts generally tear out rather than break. 2/ Because the difference between between a 3-Sigma discounted break strength & average break strength is pretty small & if you are operating this close to breaking strength you are in trouble or doing something wrong. 3/ Because you don't know what discount the other manufacturers have applied to their given break strengths. As Bigmike's "7 gamma" implies, who cares.