Hi, i want to fix an arial to a wall. it comes with a metal bracket through
which to use screws to put into plastic rawlplugs in the wall.

since i will need to take it down again in a few years; which screws should
i use that are least likely to rust? here in london u.k. i have only ever
seen 'brass' screws in the old style tapered shape with the single slot,
which i dont think are suitable.

so would you please advise a novice which of the modern non tapered screws
are easiest to get out in a few years please? (i.e. heads have not rusted
up). thanks

stainless steel. you'll be replacing the aerial or antenna if it gets
rusty to improve reception.

the mechanical style (in the USA) is called sheet metal screws. They have a
coarse thread similar to a wood screw, but have no taper, except right at
the point. The drive comes in both slotted and Phillips.

bill

"jw 1111" wrote in message
...
Hi, i want to fix an arial to a wall. it comes with a metal bracket
through which to use screws to put into plastic rawlplugs in the wall.

since i will need to take it down again in a few years; which screws
should i use that are least likely to rust? here in london u.k. i have
only ever seen 'brass' screws in the old style tapered shape with the
single slot, which i dont think are suitable.

so would you please advise a novice which of the modern non tapered screws
are easiest to get out in a few years please? (i.e. heads have not rusted
up). thanks

[quote=rider89]
"jw 1111" wrote in message
...[color=blue]
Hi, i want to fix an arial to a wall. it comes with a metal bracket
through which to use screws to put into plastic rawlplugs in the wall.

since i will need to take it down again in a few years; which screws
should i use that are least likely to rust?

I live close to the sea - it is very humid and saline.
I have found that the best external fixings are any form of good quality stainless steel bolts, be they recessed-head with Allen Key hole or hexagonal head, or posi-drive - it don't matter. Use 8mm thread and screw them into plastic plugs that require a 10mm hole. I buy my plugs from the German manufacturer Wurth as also the bolts. In 8mm the fit is exact which is not the case with other sizes.
Be sure to put some Lithium grease or Vaseline on the bolt, and do drill the wall to the exact size because a bolt has no taper and does not expand the plug to fit the hole.
I have been using this system for many years and have repeatedly found that it is possible to dismount anything, even door frames for painting, with the greatest of ease after years and years of the acutest weathering. The bolts never rust in the plastic and with grease and so do not expand and rupture the masonary. Very occassionally a plastic plug gets mangled by over tightening but that is really quite easy to replace. If the bracket is of steel put a stainless washer behind it so that it does not directly touch the wall. If your walls are limestone it is even better to put a simple homemade washer of bitumen roofing membrane or something similar but in U.K. you are probably fixing on brick which is pretty inert.
regards, Tghattaq

"jw 1111" wrote in message
...
Hi, i want to fix an arial to a wall. it comes with a metal bracket
through
which to use screws to put into plastic rawlplugs in the wall.

since i will need to take it down again in a few years; which screws
should
i use that are least likely to rust? here in london u.k. i have only ever
seen 'brass' screws in the old style tapered shape with the single slot,
which i dont think are suitable.

so would you please advise a novice which of the modern non tapered screws
are easiest to get out in a few years please? (i.e. heads have not rusted
up). thanks


Stainless steel will never rust but they are softer than galvanized and
easier to strip if using a phillips head . Brass will work. For 3 years or
less I would use plain old galvanized hex head with attached washer. Those
may not be available in UK but I bet a pan head galvanized sheet metal screw
is.

The size of the screw would be based on the weight it needs to support and
the size of the mounting holes. Also are you attaching to brick? Or what
surface?

Colbyt

I question that stainless steel is "softer" than galvanised steel, though I would agree that it is less pliable and resilient. Brass is much softer and comparatively weak and can easily snap with over-tightening. It is also expensive. You also run the risk of bi-metallic corrosion as it is a fine conductor. (Jobs that you thought were temporary have a nasty habit of becoming permanent, like girlfriends) I usually use Allen Key heads - but a Phillips in 8mm stainless and correct screwdriver bit you needs be a mighty strong guy to damage the head seriously. It is another matter with the screws used in proprietary plastic-plug fixings.
This may something for the quality of Wurth's products. Not cheap !
We have used hundreds and hundreds of such stainless steel bolts and never, ever had damage. if they are taken out they go back in the box for re-use. For fixings that require a long throw from the wall such as pipes that are bent around a corner, I use cut lengths of 8mm stainess threaded rod. Put a dome nut on the end and and with a hex bit on your cordless you can drive them in. For added strength I put a stainless penny-washer and a nut tightened to the wall.

I did omit one important particular in my first description of this system - The bolt should only go about 15mm 3/8 inch past the point at which the plastic plug begins to split. If the bolts are too long they will mangle the plug.
And again the hole in the masonary much be exact.

I have never tested such a fixing to destruction but I do have some 200+ kilo static loads hanging off two fixings only.