Tapping Holes - 1/4 Thick Aluminum Tubing

[suntravel]

Related reading:

[RJS100]

OK. I think we were talking about two different things. You were referring to the screw that moves the bracket in and out... Correct?

[suntravel]

No the screws for clamping with the knobs

Uwe

[RJS100]

Got it. Thanks.

Thanks for the info on the pull-out force. I was surprised that the pull-out force for M4.5 vs M5 was not that dramatic. With eight M4.5 screws holding the face plate to the inner tubing... I think all is good

On the outer tube, I am going to see if I can use the M5 screw if possible. I will only have about .027" between the threads and outer wall... so I may be better off using the M4.5.

his is really my biggest concern. .027" is not a lot to play with.

[RJS100]

Hello Uwe,

I did a test and tapped the M5 holes in the walls of the tube that are less than .25 inches thick. The data sheets you shared show a pullout load of 1116 lbs. for a M4.5 and 1246 lbs. for an M5.

If this was your project... would you use M4.5 screws?


CORRECTION... There are no M4.5 screws available. Looks like my only option is an 8-32 with a pull-out force of 1015 lbs. So would you use 8-32 screws instead of M5?

Thanks... Richard

[cncsnw]

If your other fasteners are metric, then stick with metric.

Just use M4.

I doubt the 30-lb per screw difference in pull-out force is likely to matter.

[RJS100]

Thanks Uwe. M4 it is! I use almost all metric screws.

[suntravel]

I would use M4 like marc also

Uwe

[RJS100]

Thanks Uwe and Marc. Very much appreciated!