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Fasteners

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Palmer

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I'm in the process of tearing down my TR3A in anticipation of taking to the body shop next year. I've noticed that almost all of the fasteners are in really bad, rusty condition. I know that many (most?) folks on this forum disapprove of stainless fasteners, so I wonder if there's some other way to keep them from rusting when I put the car back together. Should I take them to a plating shop for cad plating?
Thanks for your ideas.
 
If you want to pay the price, Macy's Garage has a complete line of stainless body hardware. Personally, I'm probably going to use the standard hardware from Moss etc., and install with some anti-sieze...but, as I get toward final assembly after the body is painted, I might change my mind. /ubbthreads/images/graemlins/driving.gif

BTW, does anybody know if the body hardware was originally painted over after the exterior panels were put on??
 
Hello Palmer,

I think you just proved the point that old Tinster
knows almost nothing about working on these TRs.

I have owned my bucket of bolts for 8 months now and
have been hard at work removing all the rust encrusted
nuts and bolts and I have been religiously replacing
them with quality stainless steel.

I have to believe my new stainless steel components are
better for my safety than the rust and dust connections
turned over to me by the PO.

T
 
I used stainless steel bolts and captive nuts on almost all the body panel hardware I've replaced. The square nuts were real hard to find. I don't think you can find cages in stainless though.

Martx-5,

My car had the British Racing Green paint over the bolt heads in some of the more accessinble areas under the hood but most of the other less accessible (visible) had some kind of red primer overspray on them. The british racing green went about half way down the engine compartment firewall, inner fender wells, and turned into this red primer as well. The engine has some kind of grease pencil written letters TR3 hand written on the side of the block. I get real jealous when I see these photos of engine compartments you can see yourself in. I think originally they were barely painted at all (At least mine is barely painted at all /ubbthreads/images/graemlins/laugh.gif). I am not the original owner so maybe someone can confirm.
 
Keep in mind that the fasteners you removed have likely been on the car since new and were run in all conditions over the years. Most likely, your car might see an occasional rain storm, but no snow and salt.
Standard zinc plating will hold up for a long time under these conditions. I don't believe that anybody is totally against the use of ss, but against it's use in high stress areas. It's your car and you make the final decision on everything.
 
Common stainless is not as strong as the original fasteners used on engine and suspension components. For these purposes, you should use a minimum greade 5 fastener and recommend grade 8 for all suspension components.

But for panels and non critical attachment on the firewall, etc. stainless is fine.

Personally I use mostly grade 8 just to be safe and coat all the assembled nuts with Boeshield T-9 protectant to protect from rusting.
 
Hi Palmer,

I would recommend new hardware where ever possible, but not necessarily stainless steel. This is not so much because of originality, but more of a safety concern in certain applications.

SS is likely fine for non-stressed or lightly stressed areas such as most body panel mounting (perhaps not door hinge bolts).

It is generally not a good idea to use SS for suspension, chassis and engine attachments. It's just too weak and brittle in many cases. Grade 5 or grade 8 would be a better choice (Use grade 8 where it's strength is needed, but keep in mind it's more brittle than grade 5, which might be better in some situations.).

Perhaps the most ideal type of hardware to use in the most important suspension and chassis applications is "AN" or "aircraft" nuts and bolts. These aren't particularly stronger, but have very high quality control and come in a much greater variety of sizes.

Unfortunately there is also tremendous variation in the quality of stainless steel hardware. The most affordable stuff is also usually the lowest quality, coming from somewhere overseas and ugraded so possibly a lot weaker than the "good stuff" costing 3X to 5X what steel bolts do. Using a bunch of SS wood screws from Home Depot recently really drove this home for me. I had to be really careful using a power screwdriver with them, the heads would strip super easily.

A primary bolt sizing consideration in many applications is that the shank of the bolt be long enough so that little or no threads are inside the hole of the parts being fastened, where the threads will act just like a milling machine gouging out the inside of the hole.

For example, one place where Triumph made a mistake originally on the 4 cyl. cars was at the front/lower generator mount, where they used a coarse threaded nut and bolt - with no shank at all on the latter - that over time seriously grinds away in the hole in the front engine plate and generator bracket.

Aircraft bolts, in particlar, are sized by the length of unthreaded shank, and often can be found in 1/16" increments (or less). In addition, AN washers come in various thicknesses so it's possible to even more precisely fine tune bolt fit.

It's not always possible, but try to always match nuts, washers and bolts: I.e. grade 5 with grade 5, grade 8 with grade 8, AN with AN, etc.

Another mistake Triumph made was putting fine thread holes in the aluminum trailing arms on the later IRS cars. During a project like yours its a great time to fix these sorts of errors.

There are hardware kits available from many of the vendors, with very similar replacement bolts for most areas, that are often a great deal, pricewise. These include fender kits, gearbox cover kits and body mounting kits. I've been very happy with the quality of these from Moss and The Roadster Factory. Kits make the job a lot easier, since it simply replaces all the hardware that normally would be used. TRF also has an upgrade kit for driveshafts that I highly recommend. The only kit that left me wanting more was a hardtop installation kit I got from TRF. It had several tough to find pieces, but omitted a few others (most of which are easily found locally, but a couple studs will need to be made up.)

You might also note during disassembly what particular nuts and bolts seemed to be the worst for rust and target those for replacement with stainless steel, wherever you feel it would be safe. I'm thinking in praticular for TR3A that there are probably some bolts around the cowl that could be improved with SS. Even an ungraded steel screw was a lot stronger.

By the way, a couple final tips. First, any and all nylock nuts should always be replaced, not reused. The nylon locking section will not hold well if reused.

Also, one place you might check out for hard to find things is www.boltdepot.com. (Many other places only sell in quantity, these folks sell everything from a single bolt to large boxes.)

In many places, I'm sure fasteners were painted over originally. This varies from car to car, I could give you some specifics about TR4 but that wouldn't help much with a TR3A. Hopefully some others can give us a list the fasteners that were originally painted on that model. There might be some detail in some of the restoration books, too, such as Bill Piggott's "Original TR" and Roger Williams' "Restoring Triumph TR2 and TR3". Piggott spends a lot more time on issues of originality.

/ubbthreads/images/graemlins/cheers.gif
 
The only thing I can add to Alan's thesis is when you can, avoid using Nyloc-style locking nuts in areas of great import if at all possible. I have heavily relied on all-metal locking nuts (they actually can be reused, although I rarely do). Areas that these types of nuts are a must would be axle flange to rear of tranny, suspension, etc. I always put a drop of high strength Lock Nut as insurance. You usually cannot find these little jewels at Home Depot or Lowes. I have a specialty shop in my area that helps me out. TRF has oft supplied me in the past.

There actually was a fellow that was marketing all-stainless nuts and bolts for the TR6 on the web. In my more gullible days, I bit and bought the kit. Later realizing, as Alan states above, that the stainless is not a structural piece of hardware (unless you pay megabucks for the true specialty stainless), I pitched the whole kit and informed the gentleman that what he was selling might be opening him to liability. I don't see his product anymore.

Bill
 
For several years I managed a shop where we fabricated and rebuilt stainless steel food-processing equipment which was shipped all over the world. This was industrial equipment including equipment for cheese making, huge storage silos sometimes 50 feet tall, pumps, agitators and many other items. Because of the variety and amount of the equipment I worked on, it is certain that everyone on this forum has had food that has been prepared, stored, or processed in some of the equipment I have worked on.

That means we used food grade stainless including the fasteners. And like I said some of this equipment was new and some was old, some 30 years or more old. The stainless was in the 300 series. 304 and 308 were the softest and 316 was the stronger and better for machining. It also resisted galling the best of the series. Most of the fasteners available off the shelf are 304 or 308, 304 being the softest and poorer quality for use as a fastener.

From this experience I found that stainless fasteners new or old are no fun. Brand new stainless nuts and bolts can (and all too often do) gall and bind before they even get tightened the first time and taking them apart increases the possibility. Re-using them is much more risky. When they bind up heat will not be much help and cutting them is difficult without a plasma torch. Oxy-acetylene is pretty much useless.

The best help is a quality anti-seize but that still is no guarantee that any of the above will not happen. And for a really fun time get the smallest amount of dirt in the threads.

I would not presume to tell anyone what to use or not use. But, for myself, I am very careful where I use any stainless fasteners. And I will never use stainless fasteners anywhere they are threaded into a part of the vehicle. Why, because when they gall and seize up they usually break before coming loose and even if they can be removed after galling they will most certainly damage or destroy the threads.

One more thing, as already stated the tensile strength of stainless steel fasteners might be a concern in many applications.
 
Alan,
Great post! Not much more that I can add, except a few details.
PLATING: The great majority of the bolts originally used on the TR3 cars were not cadmium or zinc plated, instead they were treated with a phosphate conversion caoting. This ends up giving a dull black surface that has limited corrosion resistance, but has good paint adhesion. You can have this process done at any local plater that does barrel plating. Expect to pay about a $50 lot charge for your batch of parts.
If you really want to have electroplated fasteners you should have them plated with zinc, not cad. The reason for that is that cad is a toxic heavy metal and is very difficult and expensive to have done. Other than industry experts, no one will be able to tell the difference between the two finishes. Some parts get a yellow chromate dip which gives them that golden color. This is to increase the corrosion protection.
NOTE: If you have any high strength bolts plated (any suspension or drive train parts) they must be baked at 400 degrees for 4 hours immediately after plating. This is to relieve hydrogen which is absorbed by the bolts during plating. Failure todo this can result in sudden and total failure of the bolts in service.

LOCK NUTS: The early TRs used a lot of helical lockwashers on various bolts. The bad news is that these lockwashers don't lock! The good news is that if you use a nylock nut or a metal locknut you are good to go. Lockwashers are a waste of effort and space from a functional standpoint. They don't do any harm, so if you want to look original you can put the lockwasher in place and then put a drop of red Locktite onto the threads to hold things together.
I tend to be a fan of Nylock nuts compared to all metal locknuts (except when aircraft (AN) locknuts are available). The Nylock nuts have more consistant friction and end up giving more consistant clamp loads in the joint (We have a lot of testing at my job that proves this). However; don't use Nylock nuts inside of the engine or transmission. The high temp oil will cause the nylone to soften and swell over time and possibly fail.

STAINLESS STEEL: I am not a SS fan on the fasteners used on our cars. Most of the stainless that you get on the retail marketplace is total rubish and I wouldn't use it on a lawnmower, let alone a car. Stainless steel (the commonly available alloys) is about the same strength as an unheat-treated fastener of the same size. The trouble is that it has a bad habit of galling when used with lock nuts. When that happens the only way to remove it is to drill it out. On thing to get around that is to use anti-sieze on every fastener.

AN Bolts: Aircraft bolts are good parts but you need to be carefull when buying them from surplus vendors. There are different AN and NAS parts which have the same dimensions, but totally different mechanical properties. When getting parts for the Indy cars we made sure to purchase particular part numbers that had the properties that we needed for that joint. Except for driveshaft and flywheel bolts, if you aren't racing, there isn't really a need for AN or NAS bolts on TRs, they are designed the old fashoined way....with big dirty bolts.
 
I can not remember which would be the anode and which the cathode, but I don’t think I would mix carbon steel fenders with stainless bolts. Anybody remember which one is higher on the galvanic series? Am I correct that there might be some material loss (from one material to the other) just from prolonged contact of the two dissimilar metals? /ubbthreads/images/graemlins/confused.gif
 
In a really corrosive environment there would be issues with the steel parts rusting, since they are more anodic than the stainless steel fasteners. From a practical stanpoint, given the use that our cars see, it won't really be an issue.
If we were taking these cars out in the winter in the midwest, through salt and slush, I would be a lot more worried about corrosion protection on the hardware. But since most of our cars are pretty much fair weather vehicles, the fasteners will last a long time without resorting to stainless or other long life coatings.
 
Thanks for all the great responses. I'm not too concerned about the body panel bolts - I'll just use standard steel for those. But when I was disassembling the engine compartment, I was very surprised to find rust on (for instance) the nuts holding the thermostat cover. I've restored motorcycles (Triumphs), and the use of stainless fasteners is common in that instance. Based on your responses, I'm inclined to use stainless for low stress applications unless a bolt threads directly into the block.
 
hi,
we did this before but go to your caterpillar dealer and get cat bolts. grade 8+ and superior quality control. they couldn't get quality bolts so they have their own line that meets the cat standard. stainless to carbon galvanic corrosion- you corrode the carbon steel.
rob
 
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