macrafic
Well Known Member
I agree with those who are looking for alternative screws to the AN-509 Phillip screws. However, a bit of caution is in order, so that you know the difference between a structural and a non-structural application. Van's plans do not point this out. Here is the reply I got from MicroFasteners when I asked about their screws. Microfasteners is the brand that has shown up quite a bit on various RV forums:
"Our stainless steel 100 degree flat head torx drive screws are all intended
to replace the cross recessed screws of NASM24693 (which has superseded AN507) covering non-structural screws. Their tensile strength is 85,000 psi minimum, same as the requirement for structural screws of NASM24694 (which has superseded AN509,) so the tensile strength for 8-32 screws is 1190 lbs, minimum. However their intended use is nonstructural and the grip length requirement of the structural screw spec is not met.
We emphasize that these are not mil spec screws; first no testing has been done to verify that, apart from the different drive, they meet the
requirements of either of the specs listed above, and second there is no mil spec covering these screws, to the best of our knowledge.
We don't have the AN509 spec, but the superseding NASM spec lists parts of three different compositions and hence strengths: low alloy steel at 125,000 psi, aluminum alloy at 62,000 psi and corrosion resistant (stainless) steel at 85,000 psi. Our parts are the latter. Please don't use them where the 125,000 psi parts are specified."
"Our stainless steel 100 degree flat head torx drive screws are all intended
to replace the cross recessed screws of NASM24693 (which has superseded AN507) covering non-structural screws. Their tensile strength is 85,000 psi minimum, same as the requirement for structural screws of NASM24694 (which has superseded AN509,) so the tensile strength for 8-32 screws is 1190 lbs, minimum. However their intended use is nonstructural and the grip length requirement of the structural screw spec is not met.
We emphasize that these are not mil spec screws; first no testing has been done to verify that, apart from the different drive, they meet the
requirements of either of the specs listed above, and second there is no mil spec covering these screws, to the best of our knowledge.
We don't have the AN509 spec, but the superseding NASM spec lists parts of three different compositions and hence strengths: low alloy steel at 125,000 psi, aluminum alloy at 62,000 psi and corrosion resistant (stainless) steel at 85,000 psi. Our parts are the latter. Please don't use them where the 125,000 psi parts are specified."