GOST 15521-70 Hexagon Nuts with Reduced Width Across Flats, Product Grade B

GOST 15521-70 applies to hexagon nuts with reduced width across flats, product grade B, with thread diameter from 8 to 48 mm.

HEXAGON NUTS WITH REDUCED WIDTH ACROSS FLATS, PRODUCT GRADE B Construction and dimensions Hexagon nuts with reduced width across flats, product grade B. Construction and dimensions	GOST 15521-70

Effective date 01.01.72

The design and dimensions of the nuts shall comply with those shown in the drawing and table.

Thread — per GOST 24705.

Tolerances of dimensions, form and position deviations of surfaces, and inspection methods not established by this standard — per GOST 1759.1.

Permissible surface defects of nuts and inspection methods — per GOST 1759.3.

Technical requirements — per GOST 1759.0.

The mass of nuts is given in Appendix 1.

mm

Nominal thread diameter d		8	10	12	(14)	16	(18)	20	(22)	24	(27)	30	36	42	48
Thread pitch	coarse	1.25	1.5	1.75	2		2.5			3		3.5	4	4.5	5
	fine	1	1.25		1.5					2			3
Width across flats s		12	14	17	19	22	24	27	30	32	36	41	50	60	70
Circumscribed circle diameter e, min		13.1	15.3	18.7	20.9	23.9	26.2	29.6	33.0	35.0	39.6	45.2	55.4	66.4	76.9
da	min	8.0	10	12	14	16	18	20	22	24	27	30	36	42	48
	max	8.75	10.8	13.0	15.1	17.3	19.4	21.6	23.8	25.9	29.2	32.4	38.9	45.4	51.8
dw, min		10.6	12.5	15.5	17.2	20.1	22.0	24.8	27.7	29.5	33.2	38.0	46.6	55.9	65.4
Height m		6.5	8.0	10	11	13	15	16	18	19	22	24	29	34	38

Note. Nut dimensions shown in brackets are not recommended for use.

Example of nut designation with thread diameter d = 12 mm, coarse thread pitch, tolerance field 6H, property class 5, plain (uncoated):

Nut M12-6H.5 GOST 15521-70

Same, with fine thread pitch, tolerance field 6H, property class 12, made of steel grade 40Kh, with coating 01, thickness 6 µm:

Nut M12 × 1.25-6H.12.40Kh.016 GOST 15521-70

APPENDIX 1 (informative)

Mass of steel nuts with coarse thread pitch

Nominal thread diameter d, mm	Theoretical mass of 1000 pcs of nuts, kg ≈	Nominal thread diameter d, mm	Theoretical mass of 1000 pcs of nuts, kg ≈	Nominal thread diameter d, mm	Theoretical mass of 1000 pcs of nuts, kg ≈
8	4.070	18	31.980	30	151.400
10	6.256	20	43.330	36	277.300
12	10.350	22	60.480	42	502.250
14	15.100	24	71.170	48	764.500
16	24.020	27	102.500

To determine the mass of nuts made of other materials, the mass values given in the table should be multiplied by the following coefficients: 0.356 for aluminium alloy; 1.080 for brass.

INFORMATIONAL DATA

Developed and submitted by the Ministry of Ferrous Metallurgy of the USSR.

Approved and put into effect by Resolution No. 178 of the Committee for Standards, Measures and Measuring Instruments under the Council of Ministers of the USSR dated 12.08.70.

Introduced for the first time.

Referenced normative-technical documents:

Designation of the referenced regulatory document	Clause number	Designation of the referenced regulatory document	Clause number
GOST 1759.0-87	5	GOST 1759.3-83	3b
GOST 1759.1-82	3a	GOST 24705-81	3

The validity restriction was lifted by Protocol No. 5-94 of the Interstate Council for Standardization, Metrology and Certification (IUS 11-12-94).

Reissue (September 1998) with Amendments No. 2, 3, 4, 5, 6, 7, approved in February 1974, March 1981, June 1983, May 1985, March 1989, July 1995 (IUS 3-74, 6-81, 11-83, 8-85, 6-89, 9-95).