Where to get good corrosion resistant screws? (Not stainless)

belfert · August 23, 2010, 04:41:58 AM

Anybody have any suggestions for good corrosion resistant screws that will be exposed to the weather? Not stainless as stainless tends to snap during installation. These will be self drilling pan head screws in #10 or #8.

Bright zinc screws don't seem to last exposed to weather and salt. I have seen dull plated screws such as used on enclosed trailers that seem to last longer, but not sure where to get screws like that.

JackConrad · August 23, 2010, 04:47:12 AM

Brian,
I have used a standard zinc coated (harder) screw first to "cut the threads", then remove and replace with a SS screw. Jack

kyle4501 · August 23, 2010, 04:48:19 AM

We use stainless, plated, & plain fasteners all the time here at work. The only problems we have is with poor quality - & that includes all materials. We use a local industrial supplier for most of our hardware.

Have you thought about asking the enclosed trailer dealer or manufacturer? Around here, they'll sell you what ever you want if they have it.

Dreamscape · August 23, 2010, 04:51:01 AM

Quote from: JackConrad on August 23, 2010, 04:47:12 AM
Brian,
I have used a standard zinc coated (harder) screw first to "cut the threads", then remove and replace with a SS screw. Jack

That is what I have done and it works!

bottomacher · August 23, 2010, 05:22:03 AM

Turn the clutch down on the drill when you drive them; they snap because the torque is too high and overstretches them. Watch out for offshore screw manufacturers- not all stainless is created equal.

kyle4501 · August 23, 2010, 05:32:45 AM

Ahh, pre-drilling the hole. . . .

I don't like self drilling screws to drill the hole - they don't seem to work as easily as a good quality cobalt drill bit.
I've got 2 cordless drills, so it isn't a big deal to use one to drill the hole & the other to install the fastener.

belfert · August 23, 2010, 05:46:08 AM

The metal I am drilling into is thin enough that the self drilling screws cut really well. It wouldn't really be worth the extra effort to drill first in this case.

The idea of using a regular screw first and then a stainless screw is what I will probably do. The screws used by trailer manufacturers have a really wide head and wouldn't work in this case unfortunately.

kyle4501 · August 23, 2010, 06:05:08 AM

Quote from: belfert on August 23, 2010, 05:46:08 AM
The metal I am drilling into is thin enough that the self drilling screws cut really well. It wouldn't really be worth the extra effort to drill first in this case.

The idea of using a regular screw first and then a stainless screw is what I will probably do. The screws used by trailer manufacturers have a really wide head and wouldn't work in this case unfortunately.

What?
I don't understand. It isn't worth the effort to drill first, but it is worth the effort to back out the first screw & reinstall the second ? ? ?
(not to mention the risk of stripping out the hole.)

Whatever. . . . .
Lots of things make no sense to me lately . . . . .

Busted Knuckle · August 23, 2010, 06:24:25 AM

Quote from: belfert on August 23, 2010, 05:46:08 AM
The metal I am drilling into is thin enough that the self drilling screws cut really well. It wouldn't really be worth the extra effort to drill first in this case.

The idea of using a regular screw first and then a stainless screw is what I will probably do. The screws used by trailer manufacturers have a really wide head and wouldn't work in this case unfortunately.

Quote from: kyle4501
What?
I don't understand. It isn't worth the effort to drill first, but it is worth the effort to back out the first screw & reinstall the second ? ? ?
(not to mention the risk of stripping out the hole.)

Whatever. . . . .
Lots of things make no sense to me lately . . . . .

I'm with Kyle on this one! It takes longer back out and switch screws than to pre-drill & screw.
But do it your way.

BK

belfert · August 23, 2010, 07:09:20 AM

My thoughts are that if I drill a hole I still have to thread the hole with the stainless screw. The stainless screw could snap during the threading process. I've had bad luck with stainless screws snapping. I don't have any cobalt drill bits except some #4 size bits, but I suppose I can buy one in the size I need.

bevans6 · August 23, 2010, 09:38:23 AM

I snap the heads off #6 from time to time, #8 rarely, #10 never. That's if I have a proper sized hole and the material is appropriate thickness. Depending on the material I like to use anti-seize on stainless screws since they are so prone to galling and are so hard they are a bear to drill out. I use stainless regularly but like you wish they were stronger. Cad plated or zinc plated it's a crap shoot, 10 will be fine and the 11th will rust in a week, and you can't tell them apart when installing them.

Brian

belfert · August 23, 2010, 11:15:38 AM

I ordered some stainless 410 screws from McMcaster-Carr. They are less corrosion resistant, but stronger than normal stainless screws.

I'll have to get a cobalt drill bit at the hardware store.

RJ · August 23, 2010, 01:41:42 PM

Brian -

And while you're on the run to the hardware store, don't forget to stop by NAPA (or equivalent) and get a can of Permatex Anti-Seize to keep those SS screws from galling, like Brian said.

FWIW & HTH. . .

muddog16 · August 23, 2010, 01:56:37 PM

I've been drilling a lot of holes the past few weeks, I'm using self tapping #12 cadium plated screws, and because the chassis steel is .125" thickness sometimes I end up pre drilling anyway! Using cleco's I'm use to drilling, cleaning and deburring all of the holes anyway, just take your time and enjoy it!

!!!! In some area's I've drilled through, a stainless hinge, stainless panel, .125 chassis and 3/4" plywood and not to forget a .090" aluminum panel.......isn't this stuff fun?

belfert · August 23, 2010, 06:37:21 PM

These screws are actually for my new (used) trailer I bought to pull behind the bus. I am installing new .040 aluminum panels on the sides of the trailer. I am using regular trailer screws with wide heads for most of the fastening, but some of the trim and such requires normal pan head screws.

I have a tube of anti-sieze I can use with the screws if I can find it.