GOST 8961-75 Malleable Iron Fittings with Parallel Thread for Pipelines. Locknuts. Basic Dimensions

GOST 8961-75 applies to locknuts — fittings made of malleable iron with parallel thread for pipelines — and establishes their basic dimensions.

MALLEABLE IRON FITTINGS WITH PARALLEL THREAD FOR PIPELINES. LOCKNUTS. Basic dimensions Dictile iron fittings with parallel thread for pipelines . Locknuts . Basic dimensions	GOST 8961-75 * Supersedes GOST 8961-59

The validity restriction has been lifted per the Protocol of the Interstate Council for Standardization, Metrology and Certification (IUS 2-93).

1. The basic dimensions of nipples shall conform to those shown in the drawing and in the table.

Note. The drawing does not define the design of the locknut.

Dimensions in mm

Nominal bore Dy	Thread d	H	s	D	D ₁	Mass without coating, kg, max *
8	G¹/₄- B	6	22	25 ,4	20	0 ,013
10	G³/₈- B	7	27	31 ,2	25	0 ,023
15	G¹/₂- B	8	32	36 ,9	30	0.034
20	G³/₄- B	9	36	41 ,6	33	0 ,041
25	G 1 - B	10	46	53 ,1	43	0 ,077
32	G 1¹/₄- B	11	55	63 ,5	52	0 ,109
40	G 1¹/₂- B	12	60	69 ,3	56	0 ,127
50	G 2 - B	13	75	86 ,5	70	0 ,212
( 65 )	G 2¹/₂- B	16	95	110 ,0	90	0 ,425
( 80 )	G 3 - B	19	105	121 ,0	100	0 ,513
(100 )	G 4 - B	21	135	156 ,0	128	0.938
* For reference. Notes: 1. The mass of galvanized fittings shall not exceed the mass of non-galvanized fittings by more than 5%. 2. Locknuts with Dy values shown in brackets in the table are not recommended for use.

Examples of designations

Locknuts without coating with Dy 50 mm:

Locknut 50 GOST 8961-75

The same, with zinc coating:

Locknut Ts-50 GOST 8961-75

(Amended edition, Amendment No. 1).

2. Structural dimensions and technical requirements are per GOST 8944-75.