STAINLESS STEEL ALLMETAL SELF LOCKING NUTS ART.980

Allmetal Self Locking Nuts Art.980 — Art.980 achieves prevailing-torque locking without any nylon at all: a deformed or slightly out-of-round section in the thread creates continuous metal-to-metal friction against the bolt as it's driven through, rather than relying on a polymer insert to grip the crests. That distinction matters mainly for temperature and chemical exposure — because there's no nylon to soften, melt, or be attacked by solvents, this nut holds its locking action in environments where a standard nyloc would fail outright: exhaust systems, ovens and furnace equipment, chemical processing plant, and any assembly running hotter than a polymer insert can tolerate. The trade-off is higher running torque during assembly, since the metal deformation resists the bolt more than a nylon collar does, and installation generally needs a bit more force or a power tool rather than being a quick hand-start. "Art.980" is a manufacturer's part reference rather than a national or ISO standard number, so it's worth checking exact dimensions against the specific size ordered rather than assuming full interchangeability with a differently-branded all-metal locking nut of the same nominal diameter — the locking principle is common across several makes, but dimensional details can vary. It's reusable, though like any prevailing-torque design the locking effect diminishes gradually as the deformed section wears with repeated assembly and removal, so a fresh nut is the safer choice for safety-critical joints after several reuses. A4 stainless is worth the extra cost here more often than with plain nuts, since these nuts are frequently specified precisely because of demanding thermal or chemical environments where corrosion resistance matters as much as the mechanical lock; A2 is fine for hot-but-otherwise-benign indoor applications such as general oven or exhaust bracket duty. Thread size and pitch must match the mating bolt as with any nut, with no additional sizing complexity beyond standard thread selection.

FAQs
Is Art.980 the same thing as a PAL (DIN 7967) nut?
Both are all-metal prevailing-torque designs and solve the same heat/chemical-resistance problem as a nyloc, but they achieve the lock through different mechanisms — Art.980 uses a deformed thread section within a standard-style nut, while a PAL nut uses a separate spring-steel counter ring — so the two aren't dimensionally identical even where they're functionally similar.

Does the higher running torque cause installation problems?
It just means assembly needs more force or a power tool rather than a quick hand-start; it isn't a sign of a fault, and the extra resistance is what generates the lock, so it shouldn't be reduced by lubricating the thread more than normal.

Is Art.980 reusable?
It can be reused, though like any prevailing torque nut, the locking effect diminishes gradually with repeated assembly and removal as the deformed section wears. Replacement is recommended for safety-critical joints after significant reuse.

What temperature range can this nut tolerate compared with a nyloc nut?
Because there is no nylon insert, Art.980 is not limited by polymer temperature ratings and can be used in significantly hotter environments than a standard nylon insert nut, with the practical upper limit set by the base metal and any plating rather than by a polymer component.