HI been using EZ's for 20 years without one problem on servo pushrods and engines ( 40 120 size planes all solid metal pushrods ) i only use the nylon hold on's never felt the metal would work-JUST ME ( and i can remove and replace the same nylon holder when needed ) Saw my fellow -very experienced- modelers using them this way guys flying for yearsTHE BEST OF THE BESTso i decided i would use them until one would fail-still waiting ! i do use the sullivan clips that hold the metal clevises closed at the engine arm along with the EZ - EZ's work GREAT and make mechanical adjustments to push rods EASY E you know before computer radios came along all adjustments to linkages were made MECHANICALLY believe it or not !! I still choise to do that from time to time to keep the sevos centered- never had one failand do not think i will from this point fowardENJOY REGARDS TONY