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David David is offline
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Join Date: Apr 2002
Location: Houston (Clearlake), TX
Posts: 8,624
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Brittle fracture since it failed instantly. It better not be cast. These bolts should be made from bar stock, have rolled threads and forged heads. It appears that this bolt was drilled too deep for the socket head, this reduced the cross section to where the specified torque was too much. A good material lab could section the bolt and see if the head was in fact forged, I doubt it was. At the minimum, material should be checked. It should be chrom-moly steel with about 0.4% carbon and the hardness should be around 37-40 Rockwell C.
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2014 Cayman S
2011 Cayenne Turbo
1979 930 (475 rwhp at 0.95 bar)

Last edited by David; 06-29-2004 at 05:50 AM..
Old 06-29-2004, 05:10 AM
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