Connect with us

Stubborn 3mm screws

Discussion in 'Electronic Repair' started by N_Cook, Nov 27, 2008.

Scroll to continue with content
  1. N_Cook

    N_Cook Guest

    Philips heads , but glued or varnished in and any more torque on the
    screwdriver will strip the head. I've tried heating for a minute with
    soldering iron, no change. Have now left a dollop of paint stripper over the
    heads overnight. Before using a left hand drill or griding off , any other
    ideas ? Converting the cut off shaft of a screw driver to somehow fit a
    standard (large) impact driver ?
  2. Jamie

    Jamie Guest

    Get your self an impact driver. They come in the manual or
    power driven type..
    A manual with a small hammer will do just fine to break them
  3. N_Cook

    N_Cook Guest

    Is the Makita function left-handed percusive torque with only marginal
    rotation or as a conventional power drill with hammer action, ie requiring
    rotation of the driver shaft to activate the hammering ?
  4. take your sharpest pair of diagonal cutters and grab the head from
    above. Unless the screw is made of hardened steel, the blades will
    get a good grip and allow you to break the screw loose with a twist.
    Works 98% of the time.
  5. Puddin' Man

    Puddin' Man Guest

    Heating the phillips head? Metal expands with heat.

    If it threads into metal, you might try heating the metal it
    threads into. And, of course, all manner of solvents. Do
    you have Liquid Wrench over there?

    Just little thoughts ...


    "Take Yo' Hand Out My Pocket (I Ain't Got Nothing What Belongs To You)!"
    - Rice Miller, who probably never even _heard_ of GW Bush, Paulson, etc
  6. z

    z Guest

    if it's accessible grabbing the head with a vicegrips or similar;
    maybe the "long nose" variety.
  7. N_Cook

    N_Cook Guest

    I'll have to look into this, I had assumed that motorised impact drivers
    were were rotational rather than percusive torque.
    So you can select just the percussive action in a reverse sense on its own
    without engaging the screwdriver rotation ? I've not seen it explicitly
    stated on the blurb I've read so far. Looks like a crizzy prezz if so.
  8. N_Cook

    N_Cook Guest

    Sounds useful, but I'd still have had to make some sort of long extender /
    adaptor for the current problem. But crizzy prezz likely

    In reply to someone else, heating with soldering iron , was in attempt to
    break down the glue or varnish or whatever was holding so firmly.

    Had to revert to my previous technique of grinding 2 flats into the domed
    heads and then 2 could be undone with a small 3.5mm open ender screwdriver.
    This time used an 1/8 inch cylinder centride burr in a Dremmel instead of
    small grind stone. The other 2 I could get to with a pipe wrench, of all
    things, because of the good leverage and right angle action.

    So perhaps a sight no one has seen since production of Aiwa 6900 tape decks
    in 1978. Trying to sort out a brakes problem otherwise totally enclosed and
    impossible to glimpse any sort of view, only rather confusing exploded views
    in the manual. B = brakes, S = their activation solenoid.
    the hidden jockey assembly and its activation lever train
    with secondary motor under the rubber pulley and mounting plate

    So it is possible to work on the deck without half taking the m/c to bits
    first. So you have to reassemble before checking it out and so often you put
    something back in the wrong position. But you do have to wrestle with those
    glued screws. As one of them has nearly straight action with long handle
    screwdriver but would not undo, then still a problem with the deck removed
    and a straight attack to all 4 screws to get apart.
  9. Eeyore

    Eeyore Guest

    Are you sure they're not POZI ?

    A Philips driver WILL wreck them. Read the article. Very little is Philips these

  10. Eeyore

    Eeyore Guest

    I am STUNNED that no-one except me knows that Philips heads are all but obsolete
    these days.

    You MUST use the correct driver.

    You'll probably only see Philips heads on US manufactured kit. Along with
    inches, feet, pounds, ounces, degrees Fahrenheit at al.

  11. N_Cook

    N_Cook Guest

    Come to replace them and they are not in fact 3mm , bit larger than 2.5mm ,
    they would seem to be 3 UNF threads on 1978 Japanese Aiwa AD9700. Well 3 UNF
    threaded screws have gone back in there comfortably and securely, manual
    just specifies some company stock number. Whatever they were , for the size
    of crosshead (saves argument), they were well glued in .
  12. Eeyore

    Eeyore Guest

    Which is 100% WRONG. Pozidrives have been available for about 40 years, so
    there's hardly any excuse not to use the correct term. They are totally

    Also there are LOTS of cheap Asian screwdrivers out there with a cross-head
    that are to NEITHER spec and will wreck screws very easily.

  13. Eeyore

    Eeyore Guest

    On equipment of that era it was common to indicate metric thread screws with an
    embossed dimple on the head.

  14. Graham-

    That may be true, but they don't seem to be as common as you suggest.
    When I tried to find a driver for the PosiDrive screws Hewlett Packard
    used in my counter, there were none to be found. None of the sales
    people in any of the various tool or hardware stores knew what I was
    talking about.

    I have recently obtained kits from two sources that include PosiDrive
    bits. But that is after several years of searching for them!

  15. Jamie

    Jamie Guest

    That is why I have a 100 piece security bit set.. which also includes
    the various styles of tips required for those mongrel screws.

    The set might be cheap but they work!.."
  16. Eeyore

    Eeyore Guest

    You're from the USA I take it ?

    Astonishing. It's near impossible to buy proper Phillips screwdriver here but
    1/4" drive sets often come with PZ1, PZ2 and maybe PZ3 bits and same with PH in
    front of the number.

    PZ = Pozidriv(e) of course
    PH = Phillips.

    And now there Supadriv(e) too which is AFAIK a compatible enhanced Pozidrive.

    The largest advantage it [Pozidrive] offers is that, when used with the correct
    tooling in good condition, it does not cam out, allowing great torque to be

  17. Jamie

    Jamie Guest

    I don't know where you buy your tools but it's not so. Most of the sheds
    stock Philips and any decent tool shop will have a large variety.

    Even Screwfix:-

    And certainly all the electronics suppliers like RS components.

    Pozidriv, I've been told, can be far more difficult in the US.

    You've been told incorrectly!.. those junk driving bits are all
    over here.. They make lots of screw fasteners with that kind of
    head in it."
  18. Nelson

    Nelson Guest

  19. Eeyore

    Eeyore Guest

    Well, the crazy thing is that it was a US 'invention' but Americans seem
    to be the least informed about it ! Draw your own conclusions. I suspect
    inertia has a lot to do with it. Along with inches feet, yards and
    miles. OK we still use miles in the UK. Ounces, pounds, tons (short
    presumably) as opposed to tonnes (which are nearly identical to a
    British - long - ton ), foot pounds, BTUs and all that cobblers.

    See ....

    Funnily enough Pozidriv was heavily promoted here in the UK when I was a
    young teeenager using 'kits' of popular sized screws and the correct
    screwdriver which had a blue handle in a plastic case with a transparent
    top. To this day Pozi screwdrivers still often have blue or blue
    elements in their handles to distinguish them.

    I use Stanley screwdrivers almost exclusively for serious work. There's
    a particular series with a very comfortable asymmetric moulded handle
    that is normally red (including the Phillips versions) but the Pozi
    versions are all a slightly dark blue to aid immediate identification.

  20. Eeyore

    Eeyore Guest

    Pozidriv is HUGELY superior. That's why Phillips made it !

Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day