## To what extent will a hole drilled into one side of a steel tube weaken the tube?

I want to drill a 3/8" hole in one side (not through) of a steel tube, 1-3/16" OD 1/16" wall tube in order to run cables through it. The tube is my son's go kart frame so I want to make sure it is safe to drill a hole into it. I'd appreciate any comments.
 PhysOrg.com science news on PhysOrg.com >> Leading 3-D printer firms to merge in $403M deal (Update)>> LA to give every student an iPad;$30M order>> CIA faulted for choosing Amazon over IBM on cloud contract
 Depending on the loading, it has the potential to weaken the tube fairly significantly. If failure of the tube would cause an unsafe situation, I would be hesitant.
 Recognitions: Science Advisor I don't think we can give you any "definite" advice without knowing a lot more about the situation. A small hole will increase the local stresses in the tube by a factor of about 3 times, but whether that matters is just guessing, on the (lack of) information we have. If you do go ahead with this, make sure you file the edges of the hole smooth to get rid of any "sharp corners" where a crack might start to form.

## To what extent will a hole drilled into one side of a steel tube weaken the tube?

Thank you very much for the feedback. The go kart fram is about 50" in length, the hole would need to be near the center of the two axles so thats probably the worse possible place. I won't take a chance since my son get the kart up to 80 klm/hr and we figure pulls 3G in the corners. Thanks again, this forum is an awesome resource!

 Quote by AEC Thank you very much for the feedback. The go kart fram is about 50" in length, the hole would need to be near the center of the two axles so thats probably the worse possible place.
Even though the hole is pretty big, the tube is colossal.The stress concentration factor is probably larger than 3, as the worst case is combined bending and torsion. It's really not much of a risk though, the tubes have a huge safety margin to the loads you are talking about.

Why not drill and feed the wires, either with a smaller hole, or just weld the hole back up again.

 Quote by AEC I won't take a chance since my son get the kart up to 80 klm/hr and we figure pulls 3G in the corners.
I can gaurantee you that's not the case. Superkarts with aero don't pull 3G.

Recognitions:
 Quote by xxChrisxx I can gaurantee you that's not the case. Superkarts with aero don't pull 3G.
Any type of kart can pull more than 3G if it crashes. You have to design for the worst case!

 Quote by AlephZero Any type of kart can pull more than 3G if it crashes. You have to design for the worst case!
Sorry, I can't tell. Are you being serious?

Recognitions: