Square-drive stainless screws

[JMacLeod]

I noticed the stainless screws used in the window frames are a different composition than the stainless used in the door frames and grab handles.
All were exposed to the same conditions in this spot, but only the window screws show pitting and green corrosion.

 

[ssobol]

Seems like you have something other than SS screws in the window frames.

There are different grades of SS (e.g. 304 and 316). 316 is better than 304. Eventually 304 will show some surface rust. Never seen SS turn green.

 

[thataway]

It would be interesting to see if these are ferrous metal. Take a magnet and see if it sticks to the Robertson (name of square drive--comes In 3 different sizes) screw. If green, then suspect some copper plating perhaps under chrome?

Agree with ssobol ref types of SS. However even some SS labeled "316" from China, may not really be 316 alloy.,

 

[Robert H. Wilkinson]

https://www.trawlerforum.com/forums/s3/ ... 28408.html


This contains some good info.


Rob

 

[JMacLeod]

It would be interesting to see if these are ferrous metal. Take a magnet and see if it sticks

Nope. Didn't stick.

Found a good variety of Robertson screws at Albany County Fasteners.
https://www.albanycountyfasteners.c...Search=square drive screw&Sort_By=bestsellers
I forgot the exact count, but 250 screws is enough to replace them all.

 

[JMacLeod]

https://www.trawlerforum.com/forums/s3/stainless-steel-brass-28408.html


This contains some good info.


Rob

A lot to digest.
Thanks Rob.