opening Keithley 2015, how to remove rusted screw? - Page 1
Forum section: electronics / general

author: neslekkim
author_rank: Super Contributor
timestamp: June 18, 2014, 01:08:38 pm
content: My 2015 have two screws under, so I can remove the cover, one screw is ok, but the other one is rusted, and I cannot get it to move, and are afraid of destroying it.How should I do this?, if I drill it out i guess It's too easy to rip the threads from the chassi?, and i don't want to have metal shavings inside my meterI have inquired about calibration of this meter, if the price is ok, would it be better to let them handle it, or will they return it because it's in this state? (or will they destroy it?)If I know the threading and size, I guess I can get an new screw, if I only can remove this without destroying the meter in the process..

author: tjb1
author_rank: Regular Contributor
timestamp: June 18, 2014, 01:39:25 pm
content: Not sure what they are called or where to get them in your part of the world but over here they are called Screw Out or something along those lines

author: Wytnucls
author_rank: Super Contributor
timestamp: June 18, 2014, 02:29:23 pm
content: If the meter works, don't screw with it. There is no need to peak inside, unless you have a fault that needs fixing or you want to do a teardown like Dave's.Calibration is going to be expensive, so check first against a good voltage reference, to see if it is really required. More than likely, the meter accuracy will still be within specs.Calibration is performed closed-case and any required adjustments are done through software. So, the rusty screw doesn't matter.

author: justanothercanuck
author_rank: Frequent Contributor
timestamp: June 18, 2014, 04:25:42 pm
content: How about a little WD40?

author: G7PSK
author_rank: Super Contributor
timestamp: June 18, 2014, 05:35:52 pm
content: I find that if you put a screw driver into the screw head and apply a little bit of torque in the correct direction and at the same time gently tap the end of the screw driver with a hammer the screw come loose, don't hit hard very lightly and fast is best more of a vibration than a blow.

author: SeanB
author_rank: Super Contributor
timestamp: June 18, 2014, 06:19:53 pm
content: Buy the appropriate size left hand drill, which when drilling will tend to undo the screw as it removes the head. Use a shop vacuum cleaner nozzle close by to remove swarf as it is made, and you will have the screw out or at least without a head, so you can then open the case and remove the remaining stub easily.

author: neslekkim
author_rank: Super Contributor
timestamp: June 19, 2014, 05:32:25 am
content: good tips!Quote from: tjb1 on June 18, 2014, 01:39:25 pmPig-cock they was called, changed name recently, but that small ones?https://no.wikipedia.org/wiki/GrisepikkQuote from: Wytnucls on June 18, 2014, 02:29:23 pmYeah, I was thinking about checking so there is not loads of dust etc in it, but since calibration labels are taped over the the cover and back, I thought they needed to go inside it?Tapping is know, but I didn't want to do that on an bench meter, but let some wd40 do its magic, and then, maybe it would work.

author: Macbeth
author_rank: Super Contributor
timestamp: June 19, 2014, 02:44:36 pm
content: When I encounter rusted and rounded off screws that can't be turned with a screwdriver, I use a pair of old side cutters to pinch vertically into the sides of the screwhead and twist it off that way.

author: KJDS
author_rank: Super Contributor
timestamp: June 19, 2014, 02:52:55 pm
content: Unfortunately, these are countersunk, so the easiest way is a little percussive engineering and a left handed drill bit.

author: neslekkim
author_rank: Super Contributor
timestamp: June 19, 2014, 06:31:02 pm
content: Quote from: KJDS on June 19, 2014, 02:52:55 pmDoes it exist small ones that would fit these screws?

author: KJDS
author_rank: Super Contributor
timestamp: June 19, 2014, 06:46:29 pm
content: Quote from: neslekkim on June 19, 2014, 06:31:02 pmDown to 1mmhttp://www.phantomdrills.co.uk/shop/product/left_hand_drill_bits

author: neslekkim
author_rank: Super Contributor
timestamp: June 19, 2014, 08:40:01 pm
content: Quote from: KJDS on June 19, 2014, 06:46:29 pmThanks!, I thought it only was those "screw out"thingys, but they are bigger often, these looks like they would do the job.

author: Stray Electron
author_rank: Super Contributor
timestamp: June 25, 2014, 09:18:23 pm
content: Quote from: SeanB on June 18, 2014, 06:19:53 pmThis! You'll be amazed at what a difference it makes if you use a LH drill bit! Usually the drill will start to cut in and then the screw will unstick and back right out. If you use a normal RH drill bit it will only drive the screw in tighter.LH drill bits are hard to find so I treat them like they are made of gold!

author: KJDS
author_rank: Super Contributor
timestamp: June 25, 2014, 10:07:36 pm
content: Quote from: Free Electron on June 25, 2014, 09:18:23 pmI too treat them as if made of gold, but mostly because trying to remove a broken screw when it has a broken drill bit in it is more difficult than getting a straight answer from a politician.