Polyamide 6 (PA 6)

Materials › Polyamide 6 (PA 6)

Same family as PA 66 and the same reasons to pick it — toughness, oil resistance, good wear behaviour — but it melts at 220 °C instead of 260 and fills difficult geometries better. In exchange it absorbs more moisture and sits one step below in stiffness at equal glass content. As with PA 66, what really changes from grade to grade is how much fibre is in it: from unreinforced to 50 % the modulus multiplies by almost five.

PA 6 absorbs more moisture than PA 66. The figures below exclude specimens declared as conditioned, but on many datasheets the conditioning is not stated: they are not dry-as-moulded values. On a conditioned part stiffness drops noticeably and dimensions move. It is the first thing to check on a close-tolerance component. For prolonged service at high temperature the choice has to be made on the grade, not on the family: what counts is heat-ageing data, service life, load and environment. A heat-stabilised conventional polyamide and a high-performance family are compared against the component’s actual requirements.

Each row is the median of a selection of manufacturers’ datasheets held in our archive, with the property, the standard and the number of grades stated next to the value. These figures describe the sample: they serve to compare the levels with one another, not to size a part, and they are not a guaranteed material specification. For that you need the datasheet of the chosen grade, which we supply on request.

Where a level shows no value, the documented sample was not sufficient: we prefer to remove the figure rather than publish one that does not hold. HDT and impact strength are deliberately absent, because datasheets often do not state the test condition — whether HDT is at 1.8 or 0.45 MPa, whether the impact specimen is notched — and values collected under different conditions cannot be compared.