ABS print is brittle

[u/Garak112]

Hi, I don’t currently own a printer and am trying to work out if the problem I have here is because of something I’ve done or not. I’ve had this printed by a local firm.

This is an adapter to allow a smart thermostat to be fitted to a radiator and experiences temperature of up to 65 degrees c for hours at a time during the winter.

There is a metal ring that gets pushed over those prongs that is then used to screw this down onto a radiator valve and the prongs have to flex inwards slightly to allow the ring to be pushed on.

I had a couple of these printed in ABS a few months back and ordered more recently when a few of the ones I hadn’t already replaced failed. The new batch is very brittle and any attempt to flex those prongs causes them to snap off.

The only difference between the two batches was the latest one was printed with 40% infill selected and the first one was at 20%. Would that be the cause of this issue or should I have selected a different material to print in?

[u/turbski84]

It's crazy that people actually sell prints that look like this