Tiny screw on a caliper battery cover

[paulga]

The lower screw was stripped in the head when I changed the battery.

It looks like a tiny flathead Phillips machine screw, 1.55 mm x 5 mm, pitch ~0.3 mm.

Is it possible to find the same screw?

 

[Bmarler]

Of course. I go to my local ace hardware for stuff like that. They have every size imaginable in the little bin section.

 

[Docktopus]

You can probably find one at a model railroad / hobby store.

 

[paulga]

Thanks.
Will see if the local stores have these

 

[tiltrider1]

Take a dremel tool and slot the screw head.

 

[jleonard]

Amazon

 

[paulga]

Take a dremel tool and slot the screw head.

Last time I heard cutting a slot has equivalent effect to anneling, it makes the screw head brittle and easily twist off half of the head later. Does this not apply to tiny screws?

The screw head is a countersink, now its already stuck in place. I have to first extract it.

 

[Coastal Cruiser]

I agree with the suggestion to cut a slot using a Dremel tool and small cutting wheel. Go slowly, allowing time for the screw cool as you cut.
And before you attempt to remove the screw apply some penetrating oil - follow the directions on the container.

 

[luna]

Using a Dremel with a small cut off wheel to slot the recessed screw head will undoubtably also cut into or through the battery compartment cover. Control of the cutting process is always questionable when that tool is in my hand. You may be more highly skilled.

Why don't you use a small punch, something like a sewing needle of the right size and try to gently tap the screw out, driving it counterclockwise? To be effective you need to be able to hold the calipers rigidly, got a vise? Once loosened there may be enough of the original drive socket left to spin the screw out using the right tool.
What harm can be done?

Good luck finding a replacement screw at your local hardware store.

 

[tiltrider1]

This conversation is about rescuing a tool that can be purchased on Amazon for $25. I wouldn’t waste much effort on it.

 

[SteveK]

This conversation is about rescuing a tool that can be purchased on Amazon for $25. I wouldn’t waste much effort on it.

I can hardly wait for the self help book to come out.

 

[High Wire]

Eyeglass repair kit at dollar store

 

[Bmarler]

I have trouble throwing something away due to a stuck screw too. I would use epoxy to glue in a small screwdriver. Stick the screwdriver in the screw head, use masking tape to hold it upright. Mix epoxy, toothpick it into the screw head. Let sit overnight. If that doesn’t work, then throw it away.

 

[Duvie]

Drill it out with a left handed drill bit. The bit will usually grab the screw at some point turning it out. Have not tried on such a small screw before though.

 

[paulga]

Drill it out with a left handed drill bit. The bit will usually grab the screw at some point turning it out. Have not tried on such a small screw before though.

Thanks. I'm going to try an extractor. #10 extractor (1.3mm) is the smallest I could find.

 

[paulga]

I have trouble throwing something away due to a stuck screw too. I would use epoxy to glue in a small screwdriver. Stick the screwdriver in the screw head, use masking tape to hold it upright. Mix epoxy, toothpick it into the screw head. Let sit overnight. If that doesn’t work, then throw it away.

agree with the point. But the screw head is completely stripped, I don't know why the alloy is so soft.

I once used marine Tex to try to make a new head on top of the stripped head of a screw, it was "hard as steel" after cured, but it broke away before I was able to tighten the screw.

 

[CharlieO.]

My go to tool for stripped screw heads.

CRAFTSMAN Impact Tool Set

CRAFTSMAN Impact Tool Set - CMMT14104

www.acmetools.com

 

[Duvie]

Thanks. I'm going to try an extractor. #10 extractor (1.3mm) is the smallest I could find.

I have had poor luck with extractors but 90+ percent luck with left hand drill bits. Also getting a good hole down that tiny screw is going to be challenging.

 

[Bmarler]

agree with the point. But the screw head is completely stripped, I don't know why the alloy is so soft.

I once used marine Tex to try to make a new head on top of the stripped head of a screw, it was "hard as steel" after cured, but it broke away before I was able to tighten the screw.
View attachment 159721

I meant liquid epoxy. It will fill all the little nooks and crannies as well as biting on the screwdriver tip. Just don’t glue the lid shut.

 

[Bmarler]

My go to tool for stripped screw heads.

CRAFTSMAN Impact Tool Set

CRAFTSMAN Impact Tool Set - CMMT14104

www.acmetools.com

Lol, like hanging a picture with a 15 pound hammer.

 

[CharlieO.]

Lol, like hanging a picture with a 15 pound hammer.

I’ve used it many times with success on small screws, I used to be involved with classic motorcycle repair. The combination of the shock and torque of turning simultaneously has great effect.

 

[Bmarler]

I'm quite familiar with how they work, as I've used them for decades too. It's just hard to imagine finding a tip that will fit that tiny 1.5mm screw.

 

[CharlieO.]

I'm quite familiar with how they work, as I've used them for decades too. It's just hard to imagine finding a tip that will fit that tiny 1.5mm screw.

Usually come with three different size Phillips, just use the most pointy one. I’ve surprised myself with the stripped head screws I’ve been able to back out. It’s always worth a try.

 

[KnotYet]

agree with the point. But the screw head is completely stripped, I don't know why the alloy is so soft.

I once used marine Tex to try to make a new head on top of the stripped head of a screw, it was "hard as steel" after cured, but it broke away before I was able to tighten the screw.
View attachment 159721

In this situation I wouldn't bother any further after drilling and removing the head.
The battery cover will stay in place with one screw or a tiny strip of tape.
I lost the battery cover from a similar caliper and have used tape for >20 years!
If you do manage to remove the screw, McMaster-Carr will happily sell you a bag.
M1.6 x 0.35mm is a standard Metric screw size and pitch close to what you have.

 

[paulga]

Usually come with three different size Phillips, just use the most pointy one. I’ve surprised myself with the stripped head screws I’ve been able to back out. It’s always worth a try.

I just tried the Phillips tips on the other screw. It's actually neither ph0 or ph1. Only the screwdriver that was provided in the package fits. I forgot there was a provided screwdriver when I did the battery change using a precision screwdriver. This was the reason I stripped the head. So this "Phillips" screw has some slight difference in its groove so that the universal precision screwdriver does not fit well.

With the grooves completely rounded away, doubt if the impact bit can grip

 

[paulga]

In this situation I wouldn't bother any further after drilling and removing the head.
The battery cover will stay in place with one screw or a tiny strip of tape.
I lost the battery cover from a similar caliper and have used tape for >20 years!
If you do manage to remove the screw, McMaster-Carr will happily sell you a bag.
M1.6 x 0.35mm is a standard Metric screw size and pitch close to what you have.

Thanks. So they are available on the market. But a tape is a great solution.

 

[paulga]

I have had poor luck with extractors but 90+ percent luck with left hand drill bits. Also getting a good hole down that tiny screw is going to be challenging.

Thanks. Left hand drill bits are rare to find and expensive. There is 1mm from Amazon but costs $23. It fits my use but is not cost effective for one time use.

 

[tiltrider1]

If you inadvertently used a pozi bit instead of a philips bit or vise versa, its easy to strip. Most the world doesn't even know there are two different but similar looking drive systems.

 

[paulga]

If you inadvertently used a pozi bit instead of a philips bit or vise versa, its easy to strip. Most the world doesn't even know there are two different but similar looking drive systems.

To clarify, from bottom up, the first is the precision screwdriver that stripped the screw. It barely but still gripped the groove.

The second is the factory screwdriver that I was supposed to be using. It has a less pointy tip and fits perfectly.

The others are the universal Phillips bits I tried in post 25. Neither ph0 or ph1 could even grip.

Is the second one is a special type of Phillips bit?

 

[KnotYet]

Thanks. Left hand drill bits are rare to find and expensive. There is 1mm from Amazon but costs $23. It fits my use but is not cost effective for one time use.

Apologies if this file doesn't copy well into this post but around $10 at McMaster...

High-Speed Steel Left-Hand Drill Bits​

Uncoated

Also known as reverse-flute bits, the flutes spiral in the opposite direction of other bits. Use in counterclockwise drilling applications such as removing broken screws. These bits are jobbers' length and have the rigidity and length required for most applications.

For technical drawings and 3-D models, click on a part number.

Drill Bit Size	Decimal Size Equivalent	Overall Lg.	Max. Drilling Dp.	Type	Size	Point Style	For Use On	Specifications Met		Each
				Shank
Metric
Uncoated High-Speed Steel
1.0 mm	0.0394"	34mm	9mm	Round	1mm	Standard	Steel, Iron, Aluminum, Brass, Bronze, Plastic	DIN 338	29855A26	$10.93
Uncoated High-Speed Steel Left-Hand Drill Bit, 1.0 mm Size Each ADD TO ORDER Delivers tomorrow Product Detail 3-D Solidworks Download