DIN 979 Low Crown Hexagon Nut, for Cotter Pin

The DIN 979 standard defines low crown nuts used in the assembly of threaded connections of parts with cotter pin locking. The products comply with product grade A and B; the reduced height allows the nut to be used for connecting parts in confined spaces.

Installing a cotter pin into the crown of the nut prevents self-loosening, which increases the reliability of the connection under vibration and dynamic loads.

Materials and specifications

The primary material is carbon steel with property class 04, 05, 14H. The material may be supplied with a zinc coating providing corrosion resistance. The products are also made of stainless steel A1-A5 – such alloys are not subject to corrosion and can serve for a long time in aggressive environments. Brass is also used for manufacturing.

Low crown nuts have the following characteristics:

• Thread diameter can range from M8 to M52.
• The width across flats of the hexagon nut is from 13 to 80 mm.
• The height of the product is from 6.5 to 13 mm.

Similar fastening products are manufactured in accordance with the international standard EN ISO 7038.

Application

Nuts of this type are used for assembling units of mechanisms and equipment in various branches of mechanical engineering: machine tool building, instrument making, automotive manufacturing, special equipment production and other industries. The fasteners have fairly high strength and corrosion resistance, and the reduced height allows them to be used to save space.

Dimensions of DIN 979 hexagon low crown nuts in mm:

d coarse thread	d fine thread		e	m	s	w
M8			14.38	6.5	13	3.2
M10	M10×1		18.90	8	17	3.7
M12	M12×1.5		21.10	10	19	4.7
M14	M14×1.5		24.49	11	22	5.7
M16	M16×1.5		26.75	13	24	6.64
M18	M18×2	M18×1.5	29.56	15	27	8.64
M20	M20×2	M20×1.5	32.95	16	30	9.64
M22	M22×2	M22×1.5	37.29	18	34	9.64
M24	M24×2	M24×1.5	39.55	19	36	10.57
M27	M27×2	M27×1.5	45.20	22	41	13.50
M30	M30×2	M30×1.5	50.85	24	46	14.57
M33	M33×2	M33×1.5	55.37	26	50	16.57
M36	M36×3	M36×1.5	60.79	29	55	19.48
M39	M39×3	M39×1.5	66.44	31	60	21.48
M42	M42×3	M42×1.5	71.30	33	65	21.48
M45		M45×1.5	76.95	34	70	22.02
M48	M48×3	M48×1.5	82.60	36	75	23.48
M52	M52×3	M52×1.5 M52×2	88.25	38	80	25.48

d	P coarse	P fine		de	e	m	s	w	n	sp
M6	1	-		-	11.05	5	10	2.5	2	1.6×14
M8	1.25	1		-	14.38	6.5	13	3.5	2.5	2×16
M10	1.5	1.25	1	-	17.77	8	16	4	2.8	2.5×20
M12	1.75	1.5	1.25	16	20.03	10	18	5	3.5	3.2×22
M14	2	1.5		18	23.35	11	21	6	3.5	3.2×25
M16	2	1.5		22	26.75	13	24	7	4.5	4×28
M18	2.5	2	1.5	25	29.56	15	27	9	4.5	4×32
M20	2.5	2	1.5	28	32.95	16	30	10	4.5	4×36
M22	2.5	2	1.5	32	37.29	18	34	10	5.5	5×36
M24	3	2		34	39.55	19	36	11	5.5	5×40
M27	3	2		38	45.20	22	41	14	5.5	5×45
M30	3.5	2		42	50.85	24	46	15	7	6.3×50
M33	3.5	2		46	55.37	26	50	17	7	6.3×56
M36	4	3		50	60.79	29	55	20	7	6.3×63
M39	4	3		55	66.44	31	60	22	7	6.3×71
M42	4.5	3		58	71.30	33	65	22	9	8×71
M45	4.5	3		62	76.95	34.5	70	22.5	9	8×80
M48	5	3		65	82.60	36	75	24	9	8×80
M52	5	3		70	88.25	38	80	26	9	8×90