I have a question about rack screws

[Fritz]

I've bought some APC horizontal cable management brackets and the mounting holes are a little too small to accommodate the rack screws I have. I assume that what I have are M6 nuts and bolts. The is no room to enlarge the hole so I have to find some nuts and bolts that are the correct size. I read somewhere that "M6" refers to the thread size. It's the bolt thickness that needs to be slightly smaller. There are M5 nuts and bolt available but if the "M" refers to the thread size then I'm not so sure the M5 bolt is thinker than an M6. So what do I need to make this work?

 

[pyro_]

M5 screws will be smaller than M6 ones


Sent from my iPhone using Tapatalk

 

[Fritz]

thanks.

 

[pricklypunter]

When using metric bolts, the thing to remember is that M followed by a number, in your case 6, simply means that the thread is metric with a nominal outer diameter of 6mm. An M5 would have a diameter of 5mm, for example

 

[Fritz]

When using metric bolts, the thing to remember is that M followed by a number, in your case 6, simply means that the thread is metric with a nominal outer diameter of 6mm. An M5 would have a diameter of 5mm, for example

Thank you sir. That explains it perfectly and has been added to my store of knowledge.

 

[fractal]

You don't say what type of rack you have. I am going to guess you have a modern square hole rack and use cage nuts.

The Server Rack FAQ is the first thing google found and is what I referred to last time I had the same question. I have a coffee can full of odd sized rack screws as I have standardized on 10-32 since I have some very old, pre-drilled racks which use them.

M6 is the largest of the standard rack screw sizes and the other two standard screws are imperial. I would suggest you try a 10-32 screw and nut rather than a metric M5.

 

[Fritz]

Thanks for the link fractal, It's bookmarked for future reference. I ordered some M5 cage nuts. For some reason I have a lot of M5 screws but no nuts.

The rack is an HP with square holes. I bought it new last year so I assume it's the latest and greatest.