Meaning of screw head dimples?

[jeffbro]

Can any of you machine-interested people tell me what the dimples on this Allen button head screw mean? Perhaps an alloy or hardness class signifier?

 

[Tubetec]

It does look like some kind of custom fixing , you could check the hardness by trying to cut it with a junior hacksaw , if it puts up a fight , its hardened ,

Automotive is my guess , or petrol powered tool mower ,chainsaw , hedge trimmer etc .

 

[kags]

I thought those dimples were where you are supposed to glue the rhinestones

 

[Philbo King]

Sometimes 'warranty screws' are dimpled, betting that the consumer won't remember to install it back into the same hole.

 

[jeffbro]

This screw is from a Boutique Audio Neve rack. All the top cover screws are like this one.

 

[JohnRoberts]

I could not find any standard marking convention for fasteners, perhaps custom.

JR

 

[k brown]

"Screw Head Dimples" - great name for a band.

 

[Rob Flinn]

I don't know what the dimples mean but am told by some hifi audiophiles that they sound better than the non dimpled varieties.

 

[k brown]

I don't know what the dimples mean but am told by some hifi audiophiles that they sound better than the non dimpled varieties.

Especially if you fill the dimples with a green paint pen (the youngsters probably won't get this reference).

 

[moamps]

Some screw manufacturers label the metric thread with 4 dimples. Maybe that's the case here too.



Considering that I know several audiophiles who know far more about audio technology than some wannabee audio professionals, I wanted to give a thumbs down, but that's not possible here...

 

[jeffbro]

No, I'm afraid not metric. These are #6-32.

 

[moamps]

No, I'm afraid not metric. These are #6-32.

Obviously I guessed wrong.

 

[pucho812]

this might be the answer you are looking for even though it is not a Phillips head.

https://shoppress.dormanproducts.com/not-every-phillips-head/

 

[jeffbro]

Cool, thanks. That explains the dimples I've seen so many times in Japanese equipment I've repaired.

However, trying to follow that lead hasn't given useful results yet, so still a mystery.

 

[amplexus]

Cool, thanks. That explains the dimples I've seen so many times in Japanese equipment I've repaired.

However, trying to follow that lead hasn't given useful results yet, so still a mystery.

If you see dimples on a phillps head (esp on Japanese gear) it means the screw head is a JIS socket. If you see diagonal lines from the corners it tells you it’s a Pozidrive socket. If you do a lot of work on EU or Japanese origin gear it is well worth having a set of each type of driver as it will save you a lot of headache and screw heads! Standard phillips will not mate quite correctly

I haven’t often seen markings like that on button head hex socket screws, and the socket looks standard. Best bet is it’s either a meaningless manufacturer’s mark or id or it could simply be the “grade” of the bolt for strength. (Ie: grade 2, for basic plain steel, vs grade 8 or 9 for something needed to take a lot of stress)