Aluminium tripod QR plate and a steel bolt - is it a problem?

Discussion in 'Accessories' started by Colin O, Mar 8, 2021.

  1. Not a totally photographic question, but...

    On one of my cameras I use a Manfrotto 200PL-PRO quick release plate, but due to the original 1/4" bolt not being quite long enough for my situation, I replaced the bolt with a longer one I got on eBay. However the new bolt is steel, and the QR plate is aluminium. I'm just wondering if this mismatch of a harder/softer metal can somehow damage the threads in the QR plate through repeatedly screwing/unscrewing the plate to/from the camera?
     
  2. Surely pretty much all tripod screws are steel.
     
  3. As long as the threads match (i.e. 1/4-20), there shouldn't be any problem. There could be a galling problem with aluminum, but the thread match shouldn't cause this to happen. I do have a few aluminum screws, but 99% of mine are steel.
     
  4. Steel bolt in light alloy nut can become problematic. But: QR plates are washers, right?
     
  5. Well, I've made a bit of a "sandwich" of things to screw into the camera. At the bottom there's the QR plate, above which there's a spirit level plate, with a few nylon washers in between everything, to space things out just right. That's why I needed the longer bolt. But during adjusting, I suspected I saw some very tiny metal "shavings" falling away, and that's what made me wonder if I could be damaging the QR plate.
     
  6. You 'll have to remove thread between outside your camera and the bolt's head from your bolt, for things to work right.
     
  7. There are galvanic corrosion problems between different metals, see, for example, Fixing Corrosion Between Anodized Aluminum and Steel, but unless you're working in a wet corrosive environment it's not something that will occur rapidly for steel and aluminum.
    Google has lots of info available (search 'aluminum and steel')
     
    Last edited: Mar 9, 2021
  8. I really wouldn't worry about it.

    I work with large CNC machines. They contain a lot of machined aluminium parts to save weight, so there are a very large number of steel bolts into aluminium.

    Provided you don't over tighten, it is not an issue.
     
  9. Gitzo and older Manfrotto 1/4" Whitworth bolts were brass. The ones supplied with QR plates are nearly always plated steel.
    Surely this defeats the entire object of a QR plate?
    The design philosophy is to leave the plate attached to the camera to allow Quick Release, or attachment.

    If you're going to attach the QR plate to the camera every time the tripod is used, then buying a head with a simple 1/4" or 3/8" bolt fitting would make more sense?

    Personally, I think tripod head design(ers) has/have got out of hand. With stability being sacrificed to multiple device interfaces and just plain daft locking systems and choice of materials. My most stable and robust heads still use a simple stud/bolt for attachment. Although use of an anti-rotation pin to fit in the camera base would be a sensible addition.
     
  10. Yes, of course, a QR plate is intended to be left attached to the camera. I won't be attaching/detaching it all the time. But I do also use a table-top tripod from time to time, and for the occasions when I want to use that, I intend to detach the Manfrotto QR plate. I'm just basically naive when it comes to metals/materials, and I wouldn't like to do any damage to the QR plate.
     
  11. If the connection is loose enough that the steel wears out the QR plate then it wouldn't be tight enough to hold your camera still.

    Galvanic action as mentioned by @JDMvW would be a cause for concern if the metals were immersed in water for significant periods, but thats not the way most of treat our cameras!

    If the bolts are ordinary untreated mild steel there might be a slight risk of the bolt rusting to the point it becomes difficult to remove from your camera. I think the risk of this is pretty small, but I would consider it a bigger risk than the steel/aluminium issue.
     
  12. I use Arca style QR (Really Right Stuff). The plates are thin and meant to stay on the camera. Most RRS plates have a 1/4-20 hole for other use, and the larger ones are bored to take a mil-spec sling connector. RRS camera plates are machined to conform to the bottom of the camera. Consequently they can't rotate on the screw, which is one of the reasons I don't use Manfrotto QR.
     
  13. I've made a number of custom plates, both for Manfrotto hex and Arca Swiss. Ideally, the screw you use should have the portion that passes through the plate filed or turned down so there are no threads in it. You then screw the screw through the plate, but once it's in it turns freely in the plate. The screw now only pulls the camera into the plate. If you don't do this, the screw will go tight in the plate before it's tight in the camera, and either it will strip out the plate or mount the camera too loosely. The threads in the plate are just to keep the screw from falling out, but to avoid damage you should destroy the corresponding threads in the screw, not the plate.

    An alternative to this, seen in some plates, is a non-threaded hole, with the screw retained by a snap ring, but that requires a recess in the top of the plate, and it's harder to turn a snap ring groove in the screw and to get it right.

    e.t.a. I see Jochen already mentioned the first part.
     
    Last edited: Mar 10, 2021
    Colin O likes this.
  14. The retaining screw engages the camera tripod socket, not the aluminum plate, so the material of the plate is largely irrelavent. High quality plates (and tripod sockets) are machined rather than cast, so there are fewer inclusions and less porosity which can lead to corrosion. They are also annodized rather than painted, which gives almost complete corrosion resistance.

    Plates which conform to the camera cannot turn more than a very slight amount if at all. I have purchased many RRS camera plates, and there is no free play once the plate is held against the body. Minimal screw tension is required to keep the plate tight against the body, just enough to keep the screw from backing out. Without the physical structure to prevent turning, the retaining screw must be very tight, and even so does not prevent rotation when the camera is oriented vertically. Over tightening can damage the camera body (and still not keep it from turning).

    Stress corrosion is less likely to occur between dissimilar metals. Aluminum on aluminum and stainless steel on stainless steel suffer from stress corrosion, which leads to galling. To a large extent, stress corrosion is due to micro-adhesion rather than chemical reactions.

    Aluminum filter rings tend to stick more than brass rings for several reasons. Aluminum is more flexible, causing the threads to bind. Brass (particularly leaded brass) has more natural lubricity. When aluminum corrodes, the oxide layer expands and is very hard (sapphire), whereas brass tends to oxidize as a molecular layer and is soft.
     
    Last edited: Mar 11, 2021
    petrochemist likes this.
  15. The original RRS system conceived in the l980's used the arca swiss style grooved edge plate and an anti-twist flange on the upper rear surface of the plate, which continues now. The plates all fit the arca swiss style clamp, incorporated into most ball heads. The clamp is tightened on to the plate with a twist knob or lever. There is a universal adaptable plate as well as custom design plates for various cameras and lenses, now made by many companies. All plates are attached to the camera bottom tripod threaded hole using a 1/4x20 threaded metal ( brass, plated steel) bolt. Threaded hole depths vary and varying length bolts can be used. I was able to obtain several length bolts that fit perfectly at my excellent local hardware store . I am puzzled by all this confusion!
     
    Last edited: Mar 11, 2021
  16. I like the convenience and fail-safe attributes of lever operated Arca clamps. However thousandths of an inch matter with the bevels, so it's best to used plates and clamps from the same manufacturer. Screw knob clamps are slower, but are self-adjusting if the plate size varies.
     

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