The dangers of stainless steel bolts


 
Shoot, I could have told you that stainless steel fasteners will gall up even without watching the video. Thing to remember is that water slide's bolts are structural, and proper clamping force is going to be more than a little important. In an awful lot of cases, they'll be single use fasteners because you'll break them off on disassembly. It's not just that much of an issue when assembling a grill, and for the most part, I wouldn't worry about it on a grill. I would use Seldom-Seez, either the standard silver or the hi-temp copper compound.

Edit: There is another issue with the water slide that comes to mind. With stainless' tendency to gall, you cannot use an untreated stainless fastener to pull together structural members. When you start putting a fair degree of torque on stainless fasteners, the threads don't slide past each other like zinc plated mild steel, and the friction starts to degrade/destroy the mating threads. I'd be willing to bet that there are other significant issues with that slide's assembly. WIthout the proper clamping force applied across those plates, the entire load is going to be carried through the bolt rather than friction loaded through the plates, potentially leading to a shear failure of the bolt.

Food equipment manufacturers deal with this all the time due to requirements to use non-corrosive materials and fasteners.
 
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I use SS and NeverSeize but I am puzzled by the "nickle causes galling". I use stainless in other applications (where it's not going into aluminum) and don't bother with NS and I have never had an issue. Been doing it for at least 35 years and never witnessed an issue. But I know they're brittle so I don't use them in high stress applications
 
Larry, I have started to shy away from stainless axles on grill restores for the brittle aspect you mentioned. Years ago I posted about an expensive Crown Verity Canadian-made all stainless grill. Besides the burners, the one thing I needed to replace was a snapped stainless axle.

I still go with stainless - 316 grade where possible - for nuts and bolts on my grill restores. And, as I mentioned, with Loctite or a similar anti-seize applied.
 
Stainless steel can be a pita at times. We would use coriolis mass liquid flow meters in a controlled flow loop of Ammonium Chloride. The meters were stainless steel due the corrosion issue with the Ammonium Chloride. BUT, when energized by 30 kHz mechanism in the flow meter, stainless steel becomes brittle. We ended up using hastelloy meters instead.
 
Bob Bass said:
Stainless steel can be a pita at times. We would use coriolis mass liquid flow meters in a controlled flow loop of Ammonium Chloride. The meters were stainless steel due the corrosion issue with the Ammonium Chloride. BUT, when energized by 30 kHz mechanism in the flow meter, stainless steel becomes brittle. We ended up using hastelloy meters instead.
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WAY over my head
 
I think "the dangers of stainless steel bolts" is a bit dramatic as it applies to an outdoor grill, don't you? What's the worst that can happen? It galls and you can't get it apart?

And if you don't know what you're doing, then don't do it, right?
 
Ed P said:
I think "the dangers of stainless steel bolts" is a bit dramatic as it applies to an outdoor grill, don't you? What's the worst that can happen?It galls and you can't get it apart?

And if you don't know what you're doing, then don't do it, right?
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Actually by using SS I guess the danger is you CAN get it apart LOL. Interesting tidbit. On both my Z Grill and my Member's Mark all the screws are anodized stainless steel. What's nice is it makes it a snap to get things apart if ya need to service anything
 
I've had stainless nuts get galled and stuck on stainless bolts before. Sometimes you don't even get them hand tight and they can get stuck. Using different families of stainless for the nut vs bolt is better than both being from the same family. Also, 1/4 inch and smaller are less prone to gall. I had a terrible time using some 3/8 bolts when building a camper. Eventually I switched to brass aircraft nuts on 316 stainless bolts (3/8 size). I used many (a few hundred) of them with zero problems.

Stainless is prone to stress cracking in odd ways. In the Philippines they have Jeepneys which are largely made of stainless. The welds all hold up fine but the stainless often cracks along the weld or in areas of stress where plain steel would probably not crack.

I had a stainless steel shift lever in my old Dodge truck (a welder made it for me and picked stainless because he thought it would look cool). Well, after a while it snapped off right where it was bolted to the transmission stub shaft. It snapped mid-shift in an intersection. Not easy, but I got the transmission into third (a straight shot on the stub shaft) and got home. The broken shaft looked "crystalized".

I gave it to a different welder (who teased me saying, "You know - you're supposed to use the clutch to shift") and he patched it with a sleeve. He then told me the broken lever was the engine's fault (a Cummins 6BT). He said the vibration causes stainless to stress crack. He said he sees it on motorcycles a lot. Well I can tell you the old Cummins is really good at making vibration so maybe he was right? Don't know...
 
John G (Boston) said:
He then told me the broken lever was the engine's fault (a Cummins 6BT).
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Well..... there's a little bit o' truth there.....

NV4500 5spd transmissions behind Cummins 6cyl engines in a factory build tend to spin the 5th gear nut off the main shaft over time, couple of hundred thousands miles or so. Fortunately, all you lose there is 5th gear temporarily. There's a variety of well known fixes for this, had it done in my old '99 CTD. Dad bought a '99 gasser (5.9l) with the same transmission, loaded down much heavier ('ve scaled truck & trailer at over 36k lbs.) No issues with this transmission behind a gas engine, but it's a ticking time bomb behind a Cummins, and it's all apparently due to engine vibration.

If your broken shifter was crystalized, it was almost certainly made brittle during the welding process. It'd have to be heat treated after to relieve stress and temper it again.
 
In 20-plus years of aerospace system building/ designing, we used stainless hardware everywhere.
Galling occurs with stainless on stainless application; exacerbated if power tools (speed=heat) are used during assembly (we always hand-assembled).
Galling is avoided by using lubricant during assembly and proper torque application. To minimize problems, Years ago, Heli-Coil started offering inserts made of a Nitronic 60 SS alloy designed to minimize galling.
If lubricated (with lubricant or threadlocker), galling should not be an issue for us. Remember that lubricated/ threadlockered threads require reduced torque to achieve the same clamping force compared to dry threads.
 
In our applications, there are other properties of stainless steel which I think are worth considering .
It easily work-hardens, so after it breaks it is difficult to drill out when surrounded by a softer material, such as cast aluminum…
It is surprisingly less corrosion resistant than some other metals such as brass or copper, particularly when in contact in an aqueous solution containing chlorides. Stress corrosion cracking is a real problem.
Its much lower heat conductivity than steel and aluminum will work to our advantage particularly when it is used to secure a cook box to a frame - if Weber had used stainless bolts there many grills wouldn’t have been trashed
prematurely.
This lower conductivity is not our friend when it comes to grates, it takes a bit longer for the heat to come out and sear your steak.
Just my thoughts as a retired corrosion applications engineer
😇
 
I just replace the bolts Weber used with the same material bolts on the old east west burner grills. If they held up for 20 plus years new bolts will probably last another 20. I don’t see any benefit to replacing every frame bolt with stainless from a structural standpoint.

The one cosmetic use of stainless fasteners that looks good is on the old lid endcaps that originally used a carriage type bolt.
 
My neighbor, who was in his seventies was replacing the deck on the back of his house.

He put in 6x6 pressure treated columns every 5 feet, each tied to concrete footings dug three feet below grade.

I asked him why he was building it so strong- “because I don’t want to have to rebuild it in 20 years.

My neighbor told me this story when I was building my deck, about 30 years ago.

Lol
 
BPratt said:
I just replace the bolts Weber used with the same material bolts on the old east west burner grills. If they held up for 20 plus years new bolts will probably last another 20. I don’t see any benefit to replacing every frame bolt with stainless from a structural standpoint.

The one cosmetic use of stainless fasteners that looks good is on the old lid endcaps that originally used a carriage type bolt.
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I agree that stainless screws, nuts and bolts may not make your grill last enough longer for any of us to see the difference. However, I can't tell you how many wood slat tray tables I have picked up where the screws on the bottom are a rusted mess. That rust can make its way to the frame besides looking trashy. I am sold on marine grade 316 stainless screws for this application:

IMG_0359.jpg

Other bolts and screws can become impossible to ever remove for servicing and can make rust stains that run. So, for me the stainless hardware is worth it. I think it is also a nice selling point in a flip grill situation.
 
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