1~ mm rounded Allen head

[MarkusIL]

Hello my saviors, 

Trying to get to the gearbox for the first time {+first gun, vfc hk416}, I rounded the selector bolts which are extremely small, maybe 1 to 3 millimeters. I was looking up solutions in Google but people seemed to have way easier problems {big screws}, does anybody have a suggestion for this problem case? 

View attachment 79996

View attachment 79997

 

[alex90]

try hammering in a torx bit that slight larger then the hex key size,

if that fails drill it out you shouldn't have to go to deep for it to pop the screw head  then should be able to remove the thread by hand 

assuming its not been thread locked 

then pop on eBay buy some assorted size counter sink bolts and should be golden mate   

 

[Adolf Hamster]

Few options.

Dab of glue on the hex bit, let it set before trying to remove.

If that doesnt work a torx might, but you'll want the right size.

After that something like grinding a slot in the head to take it out with a flatblade screwdriver.

And finally as mentioned get the big guns and drill it out.

In future, i  really suggest investing in a good quality set of hex drivers, really does make all the difference for the small screws you find in these things.

 

[Rogerborg]

Oof, that's as good a job of rounding out as I've seen.

As above, but you'll have a hard time putting a slot in there, and I've never got glue to work on anything that was so stuck that it had already rounded out.

Reluctantly, I'd agree with: hex bit, then drill.  If you can slot or glue, great, but since they both rounded out, I'd suspect that they might have been threadlocked by some sadist.

 

[Lozart]

Save yourself the dicking about and drill them out.

Or...

View attachment 80008

 

[Rogerborg]

Mmm, given how chewed out they are, even the hex bit is more of a token ritual at this point.

Observation: money spent on tools is money saved on drill bits.  

 

[Tommikka]

the proper tool now is a screw extractor, but no matter what you use it’s going to be joy with something that small

A screw extractor has a reversed ‘drill’ thread, which screws itself into your bolt/screw etc

A slightly different Allen key would only have worked until you totally destroyed the head - eg imperial / metric sizes, torx etc

Glueing / welding in something else sometimes works - but you have to lock in the new Allen key tighter than the resistance in your screw/bolt

Cutting the head gives you a slot for a screwdriver - unless you also cut your gun body, or further shred the head

Drilling it out brings in more issues of damaging the guns thread or leaving parts of the screw/thread inside and deeper than you can get at 

Do have a hard think about whether you have trashed a soft head, or it is thread locked in place - in which case you need to break the thread lock either with greater force (light duty thread lock) or heat. (Mid to heavy duty thread lock)

https://www.amazon.co.uk/dp/B07YTPZ35S/ref=as_li_ss_tl?SubscriptionId=AKIAJO7E5OLQ67NVPFZA&ascsubtag=688197298-311-1736137787.1634216909&tag=best_reviews_uk_1-21

 

[concretesnail]

Looking at the picture I'd suggest cutting a groove into it and using a flat screw driver. If that doesnt work then you have enough head left to try the larger torx bit wedged in it.

 

[Jacob Wright]

I’d suggest using a dremel with smallest cutting wheel to cut a slot and go at it with a flat screwdriver. 
 

Good luck!

 

[Rogerborg]

the proper tool now is a screw extractor

I wouldn't use one on a fastening that size, i.e. with the tiny extractor that you'd have to use. There's a risk of snapping the extractor, and you might end up with piece of hardened steel to drill through as well.  Ask me how I know (spoiler: see above).  I contrast that with Irwins bolt extractors which I'll reach for in preference to sockets any time I don't care about saving the fastener.

As to slotting it, I'd be surprised if you could do it without cutting into the selector itself.

Just drill the head off, you've already got a nice centring hole for it.  

 

[Lozart]

I wouldn't use one on a fastening that size, i.e. with the tiny extractor that you'd have to use. There's a risk of snapping the extractor, and you might end up with piece of hardened steel to drill through as well. 

I was going to say exactly that!

 

[Druid799]

I’ve got a small flat head screwdriver just for this job if I have to cut a slot  , basically all I did was round out the ‘blade’ and re-profile it so the bevel follows the curve of the tip for max grip , I find it works quite well . ?

this is roughly what I mean . 

View attachment 80045

 

[ImTriggerHappy]

I wouldn't use one on a fastening that size, i.e. with the tiny extractor that you'd have to use. There's a risk of snapping the extractor, and you might end up with piece of hardened steel to drill through as well.  Ask me how I know (spoiler: see above).  I contrast that with Irwins bolt extractors which I'll reach for in preference to sockets any time I don't care about saving the fastener.

As to slotting it, I'd be surprised if you could do it without cutting into the selector itself.

Just drill the head off, you've already got a nice centring hole for it.  

Decent screw extractors would be fine but it would need heating up first as there is probably a too strong threadlock involved in this problem. Cutting slots is quite often a recipe for disaster and makes me cringe every time I hear it mentioned as quite often that will just tear as well.

Easiest option is to heat the screw with a soldering iron then tap it round with a punch or flat bladed screw driver. As long as you are gentle this always works.

Then buy some Wera Hex Plus keys and stop it happening again as this is often caused by people using poorly made allen keys that they bought from amazon or halfords.

 

[Shamal]

Decent screw extractors would be fine but it would need heating up first as there is probably a too strong threadlock involved in this problem. Cutting slots is quite often a recipe for disaster and makes me cringe every time I hear it mentioned as quite often that will just tear as well.

Easiest option is to heat the screw with a soldering iron then tap it round with a punch or flat bladed screw driver. As long as you are gentle this always works.

Then buy some Wera Hex Plus keys and stop it happening again as this is often caused by people using poorly made allen keys that they bought from amazon or halfords.

I was going to say same thing ?

About the tapping with fine punch I meqn

 

[Rogerborg]

Decent screw extractors would be fine

Does that assurance come with a guarantee that you'll drill them out when they snap?

but it would need heating up first

The selectors appear to be plastic.

You know what else puts heat in?  Drilling the heads off.  That also ends the debate.

Easiest option is to heat the screw with a soldering iron then tap it round with a punch or flat bladed screw driver. As long as you are gentle this always works.

They're already trashed, so the easiest option is to drill the heads off, which takes a few seconds each, I've have done both of them in a New York minute eleventeen posts ago, and we could have skipped all the "Why-you-oughta" after that.

I mean, you could use a left-hand bit, and maybe they'll break loose and spin out before the heads come off. But either way, subtlety is for when you're trying to save the fastener.  Those are dead, dismember the corpses and move on.

 

[ImTriggerHappy]

Does that assurance come with a guarantee that you'll drill them out when they snap?

The selectors appear to be plastic.

You know what else puts heat in?  Drilling the heads off.  That also ends the debate.

They're already trashed, so the easiest option is to drill the heads off, which takes a few seconds each, I've have done both of them in a New York minute eleventeen posts ago, and we could have skipped all the "Why-you-oughta" after that.

I mean, you could use a left-hand bit, and maybe they'll break loose and spin out before the heads come off. But either way, subtlety is for when you're trying to save the fastener.  Those are dead, dismember the corpses and move on.

I bow down to your expertise it is not like I have made a decent living out of this sort of stuff for the last 28yrs.

 

[Rogerborg]

I bow down to your expertise it is not like I have made a decent living out of this sort of stuff for the last 28yrs.

Ah, but my bad advice is free.  

I'm not saying your way isn't the right way.  I'm saying that quick, simple and low risk is good enough for bodging most jobs, and in this case those heads would be off in a few seconds.

 

[Lozart]

 and in this case those heads would be off in a few seconds.

True but you'd still have the shank stuck in there. If you're lucky the cam behind the selector will be metal and you can get it out. If it's plastic then it's going in the bin with the screw shank!

Either way, life's too short to try getting M3 screws out of fire selectors with a screw extractor!

 

[Rogerborg]

My strategy is to get to the next problem in the shortest possible time.