Help in choosing screws for radiator (Note: WOOD PC Case...)

think they are m4 screws

and ebay or other places will do them in 45mm

cant say i have seen a wooden pc case before got a picture of it?

Here is a possible source:

http://www.pencomsf.com/fan-screws/fan-screws/

However, I would take one of the "too short" screws to a local hardware store or a big box lumber store and visit the hardware section.

Since you will be joining to wood you should be able to find a suitable (length, diameter, screw head, and drive ( e.g., hex, Phillips) wood screw that will work. Just remember to carefully mark and pre-drill the applicable diameter pilot holes. (And based on your photographs I know you know how to do that.)

Just out of curiousity; will you be putting any mesh over the bottom openings to keep out insects, rodents, dust bunnies, etc.?

looks like a nice solid piece of furniture

pretty sure they are m4 which are easy to find on ebay or if you have a decent ironmongers near you they should have them

might be called hardware store or something depending on the country you are in

Overall, I was thinking in terms of wood screws where the tip end does not (or should not anyway) penetrate out the opposite side of the mounting surface. My vision was (from the inside out) woodscrew (inside) > radiator > wood.

When it probably should have been common screw (flush outside) > wood > radiator > washer/nut (inside). Which actually makes more sense when it comes to future maintenance and repairs.....

That said drilling all the way through is correct. If the radiator requires the screws (actually screw, washers, and nuts) going all the way through then you will need to drill all the way through. And the holes will need to be the same diameter as the threads so the screw will slide through easily but not wobble about. Be sure that the screw's length is long enough for washers/spacers and nuts. But not too long as to the point of extending into the internals too much.

Good catch - thanks.

Not a problem. Just tricky overall to describe....on both ends.

Is your thought from the outside screw (flusher) ----> through the wood ----> into radiator (hole)? Could be round head wood screw but flush would look neater.

More on that later.....

First of all: following the radiator's installation process is the most important consideration. Vibration control, airflows, heat conductivity, etc. must be kept in mind. Do not want things vibrating and/or being noisy.

Washers are used to increase the contact surface area of screw/bolt heads and the corresponding nuts. That reduces the chances of cracking the material or having the screw pull through the material if there is too much torque or other pull (load bearing) on the screw or bolt. Especially with softwoods or any thin materials.

With harder woods that may not be a concern depending on the diameter of the screw or bolt head and the corresponding nuts (if used) on the other side.

Let's try this: Can you post a couple of pictures of the radiator and intended mounting location. That will really help (me at least) get beyond my perhaps too narrow vision of the intended build.

However will go out on a limb a bit more as I am now seeing things.

From the inside: screw --> through mounting hole(s) in radiator ---> wood (but does not go all the way through the wood and outside of the cabinet.)

In that case you would need a wood screw that just fits through the radiator mounting hole(s) without threading itself through.

Possibly like the lower (round head) wood screw shown here:

https://www.boltdepot.com/fastener-information/type-chart.aspx

The screw length being long enough to pass through the radiator mounting hole and about 1/2 of the way into the wood's thickness.

And the mounting points (where the screws will go into the wood do need to have a pilot hole also going partially into the wood. That helps guide the screw straight in, minimizes splitting/cracking. Plus the pilot hole reduces the torque needed to drive the screw into the wood thus tightening down the radiator into place. Just snug and not jammed down.

Again a couple of pictures will help, And perhaps someone else will spot something and/or offer additional suggestions.

I'd use m4 bolts & nuts with washers rather than screws personally .
Drill all the way through , washer & nut on the outside.
Far far easier to get the right tension/tightness when finally fixing the rad than using a woodscrew.

Madmatt30: Thanks. I can see that - very viable pending an actual "look see" at the radiator and mounting area.

I tend to avoid have the threaded end, washer (may be optional) and nut on the outside (or otherwise exposed) as the tip can tend to snag or scratch things plus collect more debris. But if the installation works better doing so then washer & nut outside would be okay. Use a screw length just two or three threads longer than than needed to minimize the thread ends's sticking out. And perhaps cover the thread end with a small rubber/plastic safety cap. (Setting aside countersinking options....)

you can get m4 nuts & countersunk sleeves which are incredibly tidy on both ends - not sure where you are or where you can source them where you are & generally Ive never seen them bigger than 78mm which may not be enough for you.

Really good idea!

The upper end (threaded on) is known to me as a barrel nut.

OP stated that the wood is 2 cm and I do not know what extra length would be needed to accommodate the radiator.

With any luck he may be able to purchase matched sets of the necessary length and diameter via a local hardware store or big box lumber place.

Is your radiator something like this?

http://www.newegg.com/Product/Product.aspx?Item=N82E16835106340&nm_mc=KNC-GoogleAdwords-PC&cm_mmc=KNC-GoogleAdwords-PC-_-pla-_-DIY+Cooling-_-N82E16835106340&gclid=CNXdwO3eoswCFUEfhgoddSwNaw&gclsrc=aw.ds

And you need to penetrate through the wood and then just a thread or two into the mounting holes being shown....

The photographs show four small holes both at the top and the bottom.

The holes appear to be threaded. So the screws that would normally go through the thin metal case and then into those holes would be very short.

But you now need to go through wood and need a longer length screw to reach those holes and threads without penentrating into the fins behind. The fins that prevent having a screw go all of the way thought to a washer/nut or barrel nut.

May need a better image or the manual to see the mounting instructions.....

No problem.

But regarding the "washer question": Washers are used to spread out the stress and reduce the chances of bolts or screws underload from pulling through, cracking the material, etc.. Or sometimes for spacing or standoff distance. Generally washers are provided when they should be used.

However, manufacturers know that many users do not read the assembly instructions, or follow some older, obsolete installation process (not requiring washers), and so forth.

Not uncommon for manufacturer's to now recommend something but not to provide that "something". But they do provide lots of BOLD PRINT warnings so they cannot be sued.

Instructions are becoming increasingly vague - mostly just enough manufacturer "CYA" information so, once again, you cannot sue them if things go wrong.....

And products are being built in a manner that prevents anything but the "safest" use and installation. Attempting to do anything else may or may not be viable. But at least the manufacturer cannot be held accountable.

The burden is on the end user.