Screw Type for Spreader Flag Halyard
 

My plan is to install a new pad eye for a flag halyard on the lower spreader. The spreader is an Isomat aluminum spreader with a minimum specified wall thickness of 2mm. According to the cross-section diagram the thickness at the middle of the spreader foil MAY be thicker as the diagram shows a thickened area in that location. Accordingly, the thickness then MAY be in the range of 4mm to 6mm (by eyeball).

See url for cross section drawing: http://www.rigrite.com/Spars/Isomat_..._spreader.html

1. Does anyone have experience with the Isomat spreaders to know if the center of the section has a thicker wall thickness than the minimum specified?

2. What would be the best screw type to attach a relatively small padeye: Sheetmetal or Machine? I have no problem drilling and taping for a machine screw and I'd use an antisieze compound in any event.

Any other input would be appreciated. Thanks.

Screw that
 

Hello,
Sheet metal screws are for, well, sheet metal, and even thin-walled spreaders are a bit thicker than that. So even for extremely lightly-loaded items like flag halyards we never even think of using sheet metal screws; if the metal is too thin to take a screw happily ó and here the ideal is a wall thickness roughly the same as the screw diameter ó then we'll use stainless rivets or, preferably, Riv-nuts.
Fair leads,
Brion Toss