DIN 981 Round Slotted Nut

DIN 981 is a standard for a nut used to lock bearings on a shaft in various mechanisms and assemblies. The product is a round nut with slots cut into its sides. This type of fastener is installed using a special wrench and a tab washer DIN 5406.

The nuts have a hole with internal metric thread and can be used together with bolts and other types of fasteners of the corresponding diameter. Nuts of this type are lightweight, which helps reduce the load on moving parts of the mechanism.

Materials used for manufacturing

Round slotted nuts are made of carbon steel with a property class of at least 5. The standard allows for a protective zinc coating – a thin layer of zinc applied to the surface by electroplating – the metal prevents external negative effects.

If the nut is intended for use in highly aggressive environments, the fasteners are made of stainless steels grade A2 and A4. These are acid-resistant steels that are not subject to corrosion due to special alloying elements in their composition. Stainless fasteners last much longer and reliably withstand external destructive factors.

Technical specifications of the product

Round slotted nuts have the following set of technical characteristics:

• The thread diameter of the product’s hole can range from M10 to M160.
• The thread pitch in the hole varies from 0.75 to 3 mm.
• The overall outer diameter of the nut can range from 18 to 210 mm.
• The height of the nut ranges from 11 to 85 mm.
• The width of the slots can range from 3 to 16 mm.

To use the nut, a matching tab washer of the corresponding size, made to standard DIN 5406, is selected. The tabs of the washer match the slots of the nut, providing the most secure fixation.

Application possibilities for the fastener

Nuts of this type are most widely used in mechanical engineering industries. Their main purpose is to secure bearings on a shaft and ensure their reliable fixation. The connection retains strength under constant vibration and dynamic loads. Correct selection of the fastener ensures stable operation of the mechanism and prevents emergency situations.

Fasteners of this type are used in machine tool building, automotive manufacturing, instrument making, shipbuilding and other industries – in moving components of mechanisms and assemblies. FLOK’s catalogue allows you to select nuts of the required size and configuration.

FLOK supplies fasteners in wholesale batches of various sizes: selection of fasteners with the required parameters for the task at hand. The products comply with the requirements of the standards.

d	d1	d2	h	b
KM0	M10x0.75	18	4	3
KM1	M12x1	22	4	3
KM2	M15x1	25	5	4
KM3	M17x1	28	5	4
KM4	M20x1	32	6	4
KM5	M25x1.5	38	7	5
KM6	M30x1.5	45	7	5
KM7	M35x1.5	52	8	5
KM8	M40x1.5	58	9	6
KM9	M45x1.5	65	10	6
KM10	M50x1.5	70	11	6
KM11	M55x2	75	11	7
KM12	M60x2	80	11	7
KM13	M65x2	85	12	7
KM14	M70x2	92	12	8
KM15	M75x2	98	13	8
KM16	M80x2	105	15	8
KM17	M85x2	110	16	8
KM18	M90x2	120	16	10
KM21	M105x2	140	18	12
KM22	M110x2	145	19	12
KM27	M135x2	175	22	14
KM32	M160x3	210	25	16

Round slotted nut DIN 981 is made of zinc-plated steel.