Wow I didn't know you couldn't burn off stainless steel. You learn something new everyday👍👍

A friend who worked a lot in cooking materials told me about these problems more than 20 years ago. He told me that we had a lot less seizure if we used stainless steel of different qualities: A2 screws and A4 nuts for example. But according to him, the most effective solution was a stainless steel screw with a brass nut.

Today i prepared to replace some small bolts on my 80 series Landcruiser side steps, I installed some rivnuts and thought i would do the right thing and use new 8mm Stainless Steel bolts to replace the old steel ones, however i will reconsider after watching your (as always) very helpful video. I always use an anti seize. Thank you for this timely video, great information. Glen..... South Australia

Very interesting ... I've never seen anyone actually try and oxy stainless but it was fun watching the attempt. Cheers for the demonstration and info.

This provided the answer to a problem i had when fitting new hinges to a trailer using stainless steel nylock nuts and SS bolts. About 30% of them seized when fitting them before the nut had been fully tightened, these had to be cut off. I did eventually get the job done but used a lot more nuts and bolts with the wastage. Thank you for the very useful information

I came across this problem in model boat building a number of years ago. Now I either use brass nuts or copper paste and this works well. Interesting video all the same!

Great demonstration! I have experienced this many times during my career in industrial machine maintenance. I have found you can usually use a lower grade stainless ( 18-8 ) to achieve good corrosion resistance, and they are far less prone to galling. However, there are applications where this would not be allowed.

Note that the "steel" bolts used here are actually cadmium or zinc plated, as are the nuts. SS should ALWAYS have an anti-sieze if into SS or aluminum. Then you also have to be careful not to over-tighten because the anti-sieze reduces the friction so much. And don't spin SS (or aluminum) so fast. Heat generated by friction will increase chances of gauling. Slow down and lubricate.

You have a knack of choosing interesting practical problems to make videos about. I too have found this problem with SS hardware. I've been told (but never verified) that if you mix SS grades it galls less frequently.

Hi, thanks a lot for showing this, you saved me from future disaster. I had used 6mm SS Bolts and nuts on a lathe fixture part of the stand, and did noticed it were tighter than anticipated when I had to remove them. I did however used blue marine grease on them. I will now go and examine them all. I bought them from a stainless fabricating shop in our area, not from a general store, if that could matter for types. I used just spanners in this case.

Wish I had known this years ago! My engineering course at college missed this one back in 1986! Potential disasters averted. Thank you.

At work we tend to use a stainless bolt with a standard steel nut on coal and iron ore conveyors. This way the threads stay cleaner than a steel bolt and it comes apart nice and easy as theres less or no galling

Thanks for the info. I had a bad experience trying to get nylock nut off of a stainless steel bolt and have never attempted to use nylock nuts again. I've been using thread locker instead. Now knowing about galling on stainless, I'll use them again.

Thank you. I went out of my way to acquire s/s bolts and nuts for re-installing the rear fenders on my Kenworth. I couldn't understand why these new bolts seized the way they did. I thought it was just super cheap bad foreign made bolts. Now I understand. Subscribed and thumbs up.

Excellent! I was wondering why I have had galling issues in the past specifically with SS bolts and Nylock nuts while working on my Motorcycle - now I know! Cheers!

You have just saved me a few quid as I was about to install some stainless bolts on my motorcycle refurb. Thanks for posting

Quite a few learning's from today's video. Thank you sir

One more top tip firmly stored in the noggin. Have used Stainless in the past but am steering well clear henceforth. Also I must have known once upon a time what a set screw is (I googled it - bolts have threads only so far up the shaft), I can't believe at 58 no one ever told me this, so thanks for the memory jog. As ever UH you are the go to man with all the answers.

Thanks for a great tip! I had no idea that stainless could seize up like this, I'll be thinking twice before using stainless next time if it's not absolutely necessary!

Thank you... You saved me from doing a huge mistake... I was about to change all my regular steel bolts for ss one on my truck restoration project... I changed my mind after watching your video.... Bless you.

I'm off to work for the day, I'll answer comments on my return ! I hope everyone has a great Sunday ;-)

Thank you for the demonstration! That stainless bolt galled surprisingly fast.

As always, an excellent video mate. Well done and thanks!

I learned something from this, Thanks ! When I use stainless or brass wood screws I pilot the hole and then run the same size steel screw in to thread the hole. Then replace the steel screw with a stainless or brass one. Stainless & brass screws either strip the Phillips recess, snap the screw or twist the head off when power driven.

Increíble. Jamás pensé que la tornillería de acero inox presentara tales inconvenientes. Excelente información y además muy útil. Gracias por compartirlo.

Thanks for this very useful information. So today I replaced all the SS A2 nuts with BZP nuts on some new customised SS A2 coach bolts on bells up in a church tower where everything is a bit exposed to the weather. All the SS nuts came off easily except for one that had already galled and put up a fight! A bit of WD40 and mechanical persuasion eventually shifted it.

Learned two new things by watching this video. - Thanks for sharing!

Interesting video - never knew about SS bolts/nuts. Thanks Chez - Have a great week!

I wasn't aware of any of these issues with SS. Great video.

Very interesting. Another professionally produced tip top video.

Thanks for this excellent and informative video. I seem to remember that a combination of a brass nut and stainless screw is recommended for some applications.

I was a marine engineer for almost 50 years and in the mid to late seventies we started using some stainless bolts and nuts on steam lines out on deck instead of B7 or B9 bolts and 2H nuts and it was a nightmare they would always gall even with nickel plated antiseize. On tanker ships loaded with gasoline or crude oil you couldn't use a grinder on deck. In the late 90s we started using stainless again and had very little problems with seizing even with copper plated antiseize something changed dramatically between those years with stainless steel. I'm talking about 316 stainless.

At my shop (well, it’s my boss's shop) we’ve turned threads 5 inches in diameter, both of the mating parts, in stainless. We’ve done these many times. 5” x 12 pitch. This corresponds to a 127mm by about 2mm pitch, for you metric worthies. We’ve jammed threads a few times. If you are real lucky you may get it loose with penetrating oil by slowly working back and forth. Slowly. Heat is the enema here. Other times we’ve machined out the mail member, cleaned up the female threads and made another male part. Expensive fix. The trick seems to be lube oil or anti seize, and CLEAN threads. A tiny speck of sanding grit, like what is used to deburr the entrance / exit of the thread, is the starting point for galling.

Thank you sir. Another know how or should I say knowledge for me because of you. Cheers & have a great Sunday too.

I've been wasting money and causing more problems for myself. Thank you for the information.

That's fascinating stuff that I never realised happened! Thank you for sharing this info. Cheers pal. N.

Loved this video, thanks so much for making it!!

That was most enlightening, thank you. Tony

Thank you for the video. I have had problems with SS threads but I didn't know why. Now I do.

Interesting stuff, never would have imagined this being an issue

Very informative, and basic, well done.

Hello Guys, Thanks a lot for this fruitfull video we can understand that: -Galling appears when we use standard stainless steel, I can see A2 on the bolt -Also increasing the speed mouting is not so good during mounting -Stainless is really well know against fire, this is why it is more and more used in construction We need absolutly to separate standard SS bolts and qualitative SS bolts : -Most of the stainless steel bolts strength are obtained by cold forging and this work is really important -The galling is a fact but the method to make the thread is really important. The thread rolling is important. -Last point and maybe the most important, what is the strength of the SS bolt you used? A2-70? Most of the bolts in industry have poor mechanical strength. It means that you will have many chance to enter in the pastic area of your bolts. All these points are really important against galling! You need only to find a stainless company having screws of high quality like Bumax (www.bumax-fasteners.com). They are really well know against galling and also have created same mechanical properties than steel bolts. Feel free to comment !

Top video. I learned something new about the consideration one must take when using ss nuts on ss screws.

A seemingly `simple' video, but is so informative. It demolishes my assumption and prejudice that "stainless steel is always better". Despite rusting and making things look unattractive, it may be better for me to live with this than dealing with a seized SS bolt.

Thanks for posting, don’t work too hard. I’m also off to do work in my lads salon. Thought I’d retired 🤔 all the best.

Great presentation as always!!! 😃👍

wow, you probably just saved me a lot of time and money, thank you

great information! i believe there are grades that exist that reduce the galling and also avoiding use of power tools helps a great deal too, couple with some lubricant if possible.

Great to the point video mate, thankyou 👍👍

Very interesting information -- thanks for the video!

Very good information, thanks. So does this problem occur only when using stainless steel Nyloc? The Nyloc causes much friction if you drive it too fast. I always use only hand tools or very slow rpms when fastening stainless steel Nylocs.

Good and very interesting video. Marine mechanic here so for me it's usually either s/s or brass/ monel/ inconel fasteners.

Great video. I have an off-road buggy and was considering replacing some of the older bolts for Stainless ones. Think I'll stick to BZP now...

Thanks very informative was that the rebranded Hitachi impact driver you used

Couple questions come to mind; are stainless steel bolts more of a one time use thing? What if you slowly loosen/tighten nut every to avoid much heat from generating preventing galling?

Thanks for that, I ride my bike 365 to and from work, I have gradually changed most of my bolts to stainless but there's not much stainless into stainless, most into alloy. Should be okay?

Thanks for this video, great tip...

Thank you this was extremely interesting

Being a know all I thought the worst, at first. You taught an old dog two new tricks. Subscribed.

Interesting video,I have read that PTFE provides good resistance to galling,off topic how are you getting on with Kielder impact drill as I’m about to purchase a replacement

Very informative thanks. What would you use for non-marine outdoor environments instead of stainless steel? Also does the grade of stainless steel matter? 316 A4 better than A2 or vice versa when it comes to this problem? Cheers.

Very educational, thanks.

Happened to me yesterday using SS sheet metal screws. The screws seized before going all the way in the sheet metal and I stripped the screw heads trying to drive them in. I even had the holes drilled larger than recommended and they still seized. Had I seen this video beforehand I would never have used them.

More useful information. Thank you.

Thanks. Something I hadn't realised. What happens to mild steel nuts on stainless bolts?

I am a design engineer by trade and don't profess to know the hands on stuff like yourself but when design stainless assemblies I would mix the grades of stainless ie 300 grade (austenitic st.stl) nut with 400 grade (Martensitic st.stl) bolt. This dissimilar combination worked pretty well on gas turbine bits. I didn't realise that you couldn't burn out stainless but it is full of Nickel and chrome so pretty good at resisting heat. Another point is that 300 grade stainless is weak as it comes....it's about as good as super cheap Chinese bolts, saying that 400 grade can be heat treated up to the equivalent of 8,8 bolts maybe more.....we use it for compressor blades on gas turbines so it's tough and good in tensile strength.

Great video

Well, I didn't know any of that. Good info - thanks! 👍

I've been a mechanic a long time, and just discovered this stainless galling problem. I ran a bolt once, and couldn't get it off without almost breaking a wrench. Of course it was in an extremely difficult area to access. And I didn't even know you couldn't burn stainless with a torch. Great video. Interesting comment below confirms that it was partly due to using nyloc nuts.

Good video very informative thanks for sharing👌👍

Honestly, I didn't know that. Thanks for the information!

This is a good lesson for ignorants. Naturaly I have learned this in my working days in the Shipyard.

I found this interesting but it didn't go far enough. I was a maintenance tech for 7 McDonald's restaurants for over 20 years and encountered a nightmare when the self-gapping clam-shell grills came into use. The upper platen operated at 425 degrees with a stepper motor and band pulley system to adjust from bacon to McRibb meat by computer. There was nothing BUT stainless fasteners in that mini oven. The adjustment blocks were fine thread bolts into machined bases. After ruining several under warranty, I discover a stick of copper-based anti-seize ( Locktite?)at my fastener dealer rated at 800 degrees. Problem solved. As to galling, part of the high cost of stainless bolts is the threading process. If the cutting gets rushed and the tooling dull it can tear the thread apex and the nut will grab the tear and roll up a (B-all that causes the "Gall". Other bolts are threaded by roll-pressing the threads and then heat treating.

Just had to return to this video after thinking it over. Galling is indeed a problem with SS fittings, particularly with locking nuts. But as a problem it usually only becomes apparent with the larger sized screws. I've used small ones for years with nary a problem. Even with the larger ones, if the thread is properly lubricated and you proceed with hand tools, you're unlikely to have a problem. But if you do feel it tightening up, you want to reverse and not force the issue, then either use your taps and dies to clean up the thread, or replace the nut and bolt. The problem with SS is that any heat generated is not as quickly dispersed as with other steels, leading to tightness between the two components. And running a locknut repeatedly on and off with a power tool is guaranteed to generate a significant amount of heat. In short, most of the "problem" has been artificially generated.

Knowledge bomb dropped. Good information UHM. Cheers 👍

Good info.Thanks!!!

Wow, I've honestly never heard of this strange phenomenon! Incredibly insightful Chez, cheers!

Another enlightening video! So SS bolts and SS nuts together causes this problem? Or a mixture of mild steel and SS? Cheers

Thanks for all the wonderful information. I couldnt understand why my ss nuts were jamming on the bolts. Now I know.

Very interesting I had no idea about these problems!

Well I for one don’t mind admitting I’d never heard of this. As you said, I thought SS was the better choice nearly always (actually, always) Thanks for the video 👍

Good to know, I never knew this info. 🍺👍🏽

Interesting. Thanks. If a non nylock nut is used, will it still gall up? What causes the galling? Heat? Also, if the nut is tightened by hand (rather than using a drill) then will the nut come off easily in future. Many thanks.

Good video, nice to know. I recently replaced the bolts and nuts on the roof rack of my truck for stainless steel since the steel ones that was on there had almost corroded away to the point of no longer being able to keep the thing together (this truck sits outside next to the ocean 24/7 and corrosion is a massive pain the ass). I wondered why they don't just do stainless steel on all the bolts of the truck, apart from cost I guess this answers my question. I'm still happy that I swapped those to stainless though, since I never have to undo/redo those bolts so seizing won't bother me so much and now, with the stainless bolts and nuts, it should basically last for the lifetime of the roof rack and/or truck.

great video. i didnt know you couldnt burn off stainless. what do you do if you cant get a grinder in at it. why does the stainless siese up like that . is it because its soft and kinks the threads and crossthreads

very very useful info, would stainless bolts into steel captive nuts do the same? i was thinking of using ss bolts to replace some of the grotty steel ones on my classic car for the removable service stuff what type of 'dress up ' bolts would you recommend, chromed steel? thanks, and thanks for the great info.

Thanks for posting video enjoy work😀😀

Interesting video Chez. I knew about stainless galling, but didn't realise how quickly is occurs. You can see swarf hanging out between the nut and bolt. Useful thanks.

Can't gallong be prevented or mitigated by threading the nut on (or the bolt into) at a very slow speed so as to prevent heat build up due to friction ?

What a lot of people don't know is that oxyacetlene torches work by first oxidising the workpiece and then blowing that oxide off. And stainless steel resists oxidation... Quick question though, would you treat stainless steel bolts/screws the same as nyloc nuts (i.e. just one use) or can you replace on removal without future issues?

Is the solution to use a spanner or wrench to fasten the nut, rather than a power tool? A lot of intersting info in the video, thank you.

In my work I use stainless steel bolts and nuts ONLY once. Especially where there is a lot of heat involved. The only real benefit is that these do not rust, but other than that they offer absolutely no advantage at all. Once I loosen a stainless nut or bolt it gets replaced.

does it occur if only one, nut or screw is stainless and other is mild?

Stainless nylocs on stainless screws equals disaster. For many years I worked in a marine environment where it was necessary to use stainless fixings - beacons at sea,marina pontoons etc. If nylocs had been used ,you could virtually guarantee that one of the fixings would've "picked up" and have to be cut off. This is a ball ache ashore but a nightmare stuck on a rock ,miles from land. Blessed be the advent of the battery grinder and thin cutting discs!. Anti-galling paste is of some help but not guaranteed to work .In all the years I did it, I never had a plain nut come loose provided it was correctly used.In my view, stainless nylocs are the work of the devil.

Very interesting .

Interesting info.

I've been educated once again, thank you.👍

So how would you cut it off is there any way to? Apart from a drill or grinder. Like a Tig welder or something. What would get the metal hot enough to burn? How do they cut stainless steel into shapes?

So how do you prevent Galling? Just put it slowly by hand? Or just not running the nut/bolt back and forth often?

Thanks. So what would one do to remove said stainless steel bolt?