GOST 8968-75 Steel Connecting Parts with Cylindrical Thread for Pipelines P=1.6 MPa. Lock Nuts. Basic Dimensions

GOST 8968-75 applies to steel lock nuts with cylindrical thread, zinc-plated and uncoated. Lock nuts are used to connect water and gas pipes with a sealing gasket in heating, water supply, gas supply and other systems operating in non-aggressive media (water, saturated water vapor, combustible gas, etc.) at a media temperature not exceeding 175 °C and pressure P=1.6 MPa.

STEEL CONNECTING PARTS WITH CYLINDRICAL THREAD FOR PIPELINES P=1.6 MPa. LOCK NUTS. Basic dimensions Pipe steel connections with cylindrical thread for pipelines P=1.6 MPa. Lock-nuts. Basic dimensions	GOST 8968-75 Supersedes GOST 8968-59

The basic dimensions of lock nuts shall conform to those shown in the drawing and table.

Nominal bore Dy, mm	Thread d	H	S	D	Weight without coating, kg
		mm
8	1/4² pipe	6	22	22.4	0.014
10	3/8² pipe	6	27	31.2	0.021
15	1/2² pipe	8	32	36.9	0.037
20	3/4² pipe	9	36	41.6	0.044
25	1” pipe	10	46	53.1	0.076
32	1 1/4² pipe	10	55	63.5	0.105
40	1 1/2² pipe	10	60	69.4	0.113
50	2 ² pipe	10	75	68.5	0.174
(65)	2 1/4² pipe	12	95	110.0	0.334
(80)	3 ² pipe	12	105	121.0	0.347
(100)	4 ² pipe	14	135	156.0	0.660

Notes:

1. Lock nuts with Dy values shown in parentheses are manufactured upon customer request.

2. Deviations of dimension S are per GOST 6424-73.

Examples of designations

Lock nuts without coating with Dy=40 mm:

Lock nut 40 GOST 8968-75

The same, with zinc coating:

Lock nut 40-Ts GOST 8968-75

Lock nuts are manufactured in accordance with the requirements of GOST 8965-75.