Brian's comments are correct, in my opinion. If you will look at the underside of a bolt head, you will see a nice little radius , which is a stress reliever. (also see recent comments about radii in crankshafts). In fact, there is a right way to turn the washer so that the punch side is toward the head.
I've been a Designee, then Tech Counselor for about 33 years, and a Mechanical engineer for 48 years, and have never seen a satisfactory REASON for a limit of two washers under a nut. More to the point, where the bolt is carrying a shear load ( think WAFs ) you need to be absolutely sure that the body of the bolt passes completely through the fitting, not threads in the fitting. At LEAST one thick washer, and as many as needed to allow visual inspection to confirm that the nut is torqued properly, not bottomed out on the threads. SEE AC43-13-1B, Section 7-37, which says maximum 1/8 inch of washers, but no reason stated. Ron Freiberger mail to ronandmar...@earthlink.net -----Original Message----- From: krnet-bounces+ronandmartha=earthlink....@mylist.net [mailto:krnet-bounces+ronandmartha=earthlink....@mylist.net] On Behalf Of bgd...@vvm.com Sent: Thursday, June 23, 2005 8:52 AM To: KRnet Subject: Re: KR> Re:wing attach Hi All! I'm of the opinion that a washer under the head is best for spreading the forces out more evenly. Also when the bolt is turned on installation the proper way is to only turn the nut. While I know that this does not always happen. Having a washer under the head will tend to reduce scratches and stress risers. Just my opinion Brian G. Douglas
