Can I use hole saw on these plastic boxes?

[Levinson]

I want to drill a small hole on the side of a clear plastic box with a hole saw to mount a small bulk head.
I'm not sure if I can safely drill a hole on these plastic without them cracking.
Also, I'll likely need to drill from outer side of the box due to the space restictions (because the box is not big enough that I can't position the drill from the inside of the box), Is it safe to drill this way?

I haven't decided on which box to get but I have 2 that I'm currently looking at.

One is made of hard PET. Well, it says the product is made of PET+ABS but I just assumed the lid is made of ABS and the box is made of PET. (Please correct me if I could be wrong on this).

The other one is made of SAN plastic.

 

[a.ocellaris]

I recommend using a step drill bit to reduce the chance of cracking, or using smaller bits and work your way up to the size you need.

 

[commod0re]

PET+ABS usually indicates a PET/ABS blend. The PET will lend some of its ductility to the ABS and make it less brittle which should also mean it’s less prone to cracking than ABS but the actual amount would depend on the specific blend

SAN plastic is hard and brittle and will be the more difficult between the two but it can be possible with careful technique

In either case, go slow and use light pressure, try not to let the saw teeth dig into the plastic, and support the back side of wherever you’re cutting with a piece of sacrificial wood or similar so that the plastic wall won’t bend while you are cutting. If you have one, use a drill press or drill guide to help keep the saw angle as consistent as possible

 

[Levinson]

I recommend using a step drill bit to reduce the chance of cracking, or using smaller bits and work your way up to the size you need.

PET+ABS usually indicates a PET/ABS blend. The PET will lend some of its ductility to the ABS and make it less brittle which should also mean it’s less prone to cracking than ABS but the actual amount would depend on the specific blend

SAN plastic is hard and brittle and will be the more difficult between the two but it can be possible with careful technique

In either case, go slow and use light pressure, try not to let the saw teeth dig into the plastic, and support the back side of wherever you’re cutting with a piece of sacrificial wood or similar so that the plastic wall won’t bend while you are cutting. If you have one, use a drill press or drill guide to help keep the saw angle as consistent as possible

Thank you for the great advice.
I might get a step drill bit. I have hole saw bits and used it on acrylic sheet in the past but not step drill bits. Don't have any experience with them.

 

[Reef Jedi]

Amazon sells some good stepper bits for cheap and usually come same/next day. That’s what I did and have used them more than I thought I would.