I hope this helps some of you in some way.
I had to change the propellers on my Mini 4 Pro today, but thanks to purchasing this screwdriver it went absolutely without a problem at all - Warmed the end in boiling water before use, I took it firmly but slowly and it went without a hitch.
This was a relief as you may remember the nightmare @SparkyFPV saved me from when it all went tits up with my Mini 3 Pro last year 
But here’s the screwdriver in case anyone’s interested - it’s a Japanese head.
Did you try the supplied screwdriver?
I know it’s not great quality, but did you ‘have’ to use a 3rd party one?
Oh god yes, I tried the supplied one many times, just useless.
You can’t get any pressure behind it as it’s so small, plus it wasn’t kind on the screw heads.
why? (new one to me)
Apparently it helps melt the Loctite blue glue that is on the end of the screws to help keep them in place.
Lots about it here: Prop screws are too tight,I cant take them out for replacement | DJI FORUM
After reading this topic, and as I have only recently purchased the mini 4 pro I thought I will try and undo one of my props, in case I have a mishap out in the field, I’m glad to say it came undone fairly easily with a Wera 118020 Kraftform 2050 Micro Phillips Screwdriver PH00, I already had purchased for my previous older drones, I also found that the Wera PH0 and Ph1, in the same Kraftform series, are excellent screwdrivers for small screws, looking at the DJI supplied screwdriver I don’t think that would have undone the prop screws, unless they are loose. I put a link below where you purchase these excellent screwdrivers from, this was the first link I came across, I cant remember where I purchased mine from.
Hope this helps anyone trying to remove the props, as I did not need to use any hot water to soften the locktite.
Was just trying to be helpful 
it was, never thought about warming up the tip of the screwdriver to aide in breaking the loctite … not sure how well it really works (temp of screwdriver tip and thermal capacity or the screwdriver and conductivity of the screwdriver tip considered to transfer the heat (warmth) to the screw
worth a shot …
my experience of loctite is that it needs real heat when installed in a proper location onto a proper bolt (M10 or above, something like differential crown wheel bolts) where an extra weetabix is required (or an extension tube for leverage) but quality tools that don’t deform as soon as it’s removed from the packet and just sees the screw it’s about to aide in releasing or are sold as one time use only tools is always a benefit
This was discussed at length a few months ago:
It appears that (although it looks like a Phillips screw) its actually a JIS screw (as pointed out by @stegib earlier in this thread) … no, I had never heard of them either!
They are JIS - Japanese Industry Standards- screws which are similar but different to Ph screws. The JIS screwdriver will locate right into the X on the screw head - a Ph driver won’t fully engage and can wind out and damage the X making release very difficult 
Sounds really useful. I am buying one as it is too late when you are out without one and the screw is stuck. Thank you @stegib
same here, had to cut the blades off after the threads have rounded,
Thanks Sparkorc, helpful post. If the supplied tool had a larger handle, it would do the job safely. As it is, there is a risk of damaging the screw head. As it happens I do have one with a larger handle and the screws are easily withdrawn without heating.
On my Mini 3 props, I have only used the DJI screwdriver. It was quite difficult to turn, but seemed to be a very good fit.
I would guess that DJI only supply a small screwdriver to make it difficult to over-tighten the screws, which are extremely tiny.
Mini 3, Mini 3 Pro & Mini 4 Pro propeller blades are identical (same part number on the blade), but the screws are different types and sizes, so they are sold as different parts, each pack envelope containing 2 blades (A or B) and 3 screws.
M3 prop screws: M1.8
M3 Pro & M4 Pro prop screws: M1.2
(Taking screw size from my micrometer measurement.)
As a newbie with a Mini 4 Pro, I’ve just heard about the issues of DJI supplied PH00 screwdriver. After some internet scouring, I’ve just received a J00 screwdriver from these guys: https://polarbearcamera.com/ Hopefully it’ll be a while before I need to use it.
Question on this - you mention heating the screwdriver to help melt the glue that DJI uses, but when I replace the blades, I won’t be using any glue… should I be? Or just checking them regularly.
The screws come with a lock tight solution already applied to the threads. Make sure you have a good screwdriver to remove the old ones and you should be fine
Checking the prop screws on a regular bases is a good idea
Yesterday I changed the props for super stealth master screw - tested the drone this morning, and whilst in the air, and descending, I briefly got a message that the motor was unable to turn. It just flashed on the screen, with no discernible change to the attitude of the drone. Checked everything on landing, and can’t feel any problems with rotations. Could it be the new propellers? I got them from Amazon. I’ll test again later.
Always a possibility & is why I always stick with the originals but others may have different opinions or not experienced any problems or errors on screen,
My go to now ( as you say you’ve checked them ) would be to put the originals back on & see if you still get the warning ( if you don’t get the warning ) then possibly the props / after market ones maybe the problem.
Edit : just found this on the net on a few different threads which some are having problems when using master air screw props it says this as follows …
in some cases when high speed breaking or rapid manoeuvre is performed, a motor current error could be triggered. Please note that this is not an overload error, but lower power draw recognised by the drone controller as a potential problem
Apparently some have fixed it in the gain & expo settings giving it a tweak & it says trying to find the sweet spot within those settings so this error does not occur, myself have never adjusted any gain & expo settings & I’ve heard some say not to play with them unless you know what your doing,
This video from Ian explains about those settings for better understanding, it does not mention master air screw & this is for the air 2s but it’s just to give you an understanding on those settings & what they do, I hope that makes sense,
Thank you… I did a second test flight, did the same things I did first time, and no issues… the error (according to the flight log) lasted less than one second - so I did wonder if something was sucked in and out causing the problem. It is windy at the moment, and there’s lots of tiny seeds coming off the trees… or I’m looking for a reason… I’ll chance one more flight - if nothing happens then I’ll carry on regardless…
