Cup Washer

thingiverse

A Cup Washer is used when using countersunk screws on an otherwise incompatible surface. I designed this for attaching trellis to block off the overhang on my back deck. Countersinking the trellis causes the batten to split (a fact that I discovered early on). Using a Cup Washer is the obvious answer except that generally most Cup Washers are merely pressed tin... a material which would quickly rust in the weather. So, I whipped up these 3D printed versions. Being plastic they won't rust and plus I was able to print them in a colour that matched the trellis.