How Strong Are SLS Printed Parts?

A question we often get asked is “How strong are SLS printed parts?”.

One option is to have your Sintratec Kit prints parts out of a nylon (PA12) powder, which is fused together by a laser. This method raises questions of strength, because the printed part is not a solid chunk of nylon. On the flip side, sintered nylon is surprisingly tough and holds detailed features well.

Sintratec PA12 parts have a tensile strength of 47.8 MPa and an elastic modulus of 1.75 GPa. This places printed nylon around half as strong as fiberglass and half as rigid as PVC. Strength, of course, is dependent on layer orientation in the printer, with the Z-direction being the weakest. Printed nylon also tends to be more brittle than an elastic medium and will snap during failure instead of deforming. If these properties are considered during the design phase, we can engineer some pretty tough parts!

This year we wanted to run an in-house test on the strength of a printed PA12 part.  To do that, we printed a chainlink replacement with an exterior patterned detail.

We then hung a 5-gallon bucket full of water from the ceiling using, while using the printed chainlink replacement amongst the other off-the-shelf steel components. The bucket weighed in at a whopping 45 pounds!

This demonstration illustrated that the Sintratec Kit can produce strong parts that also have a lot of detail.