DIN 961 Full-Thread Bolt

A full-thread, fine-pitch bolt whose parameters meet the requirements of the DIN 961 standard is referred to as a machine-building bolt. This is the field in which fasteners of this type are most commonly used. The product has high strength and resistance to mechanical and chemical effects, and withstands temperature fluctuations well.

Among the regulatory documents, some are considered equivalents of the German standard DIN 961:

• Russian GOST 7798-70;
• European EN 28676
• international ISO 8676.

FLOK specialists note that bolts marked according to different standards may have some differences, and their interchangeability always requires a professional verdict. To avoid mistakes when selecting fasteners, it is best to consult FLOK staff.

Physical and technical characteristics of the DIN 961 full-thread bolt

The name of the fastener makes it clear that its shank is fully covered with thread. According to the standard, it must have a fine or extra-fine pitch. The head configuration is hexagonal, for tightening with any type of wrench. The DIN 961 bolt is part of a detachable joint consisting of this element plus a nut and a washer (flat or lock) of the corresponding size.

The main materials used to manufacture a high-strength bolt with full fine thread are:

• carbon steel alloys with property class 5.8, 8.8, 10.9, 12.9 and a zinc-plated coating applied electrolytically;
• austenitic chromium-nickel steels of grade A2 and A4, which contain molybdenum in addition to chromium and nickel;
• brass and polyamide polymer of grade PA 6.6.

FLOK supplies brass and plastic bolts by special order; requests should be submitted in advance. The lead time for such orders ranges from 2 weeks to a month.

Application of DIN 961 bolts

The manufacture of all types of machine tools, technical equipment, machines and mechanisms is the main industrial sector where DIN 961 full-thread bolts are most widely used. In addition, they are used:

• at instrument-making enterprises;
• in construction, mainly for the installation of metal structures;
• in the oil, gas and chemical industries;
• in food and agricultural production.

DIN 961 bolts made of austenitic stainless steel with added molybdenum are indispensable for assembling structures designed to operate in seawater, as well as in contact with acids and alkalis.

FLOK capabilities

FLOK supplies some varieties made to order. If the required product cannot be found while placing an order online, call the phone numbers listed on the website.

Consultants will help you understand product parameters, check current availability, and accept an order for the supply of DIN 961 bolts in various configurations:

• made of the required raw material;
• with a specific type of protective coating;
• with a specified thread type: metric, inch, American, British, Whitworth.

Product quality is confirmed by warranty certificates. Delivery is available to any location across Russia.

Pitch for coarse and fine thread

Bolt parameters		Nominal thread diameter D
		M8	M10	M10	M12	M12	M14	M16	M18	M20	M20	M22	M24	M27	M30	M36	M42	M48	M56	M64
Thread pitch, P		1	1	1.25	1.5	1.25	1.5	1.5	1.5	1.5	2	1.5	2	2	2	3	3	3	4	4
Head height, K		5.3	6.4	6.4	7.5	7.5	8.8	10	11.5	12.5	12.5	14	15	17	18.7	22.5	26	30	35	40
C	min.	0.15	0.15	0.15	0.15	0.15	0.15	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.3	0.3	0.3	0.3
	max.	0.6	0.6	0.6	0.6	0.6	0.6	0.8	0.8	0.8	0.8	0.8	0.8	0.8	0.8	0.8	1	1	1	1
R		0.4	0.4	0.4	0.6	0.6	0.6	0.6	0.6	0.8	0.8	0.8	0.8	1	1	1	1.2	1.6	2	2
A max.		3	3	4	4.5	4	4.5	4.5	4.5	4.5	4.5	4.5	6	6	6	9	9	9	12	12
Circumscribed circle diameter e, min (fine thread)	DIN 961	14.38	18.9	18.9	21.1	21.1	24.49	26.75	30.14	33.53	33.53	38.85	39.98	45.2	50.85	60.79	71.3	82.6	93.56	104.86
	ISO 8676		17.77	17.77	20.03	20.03	23.36					37.72
Width across flats, S (fine thread)	DIN 961	13	17	17	19	19	22	24	27	30	30	32	36	41	46	55	65	75	85	95
	ISO 8676		16	16	18	18	21					34
Bolt length, L	Min.	16	20	20	25	25	30	35	35	40	40	45	40	55	40	50	90	100	110	120
	Max.	80	100	100	120	120	150	160	180	200	200	220	200	200	200	200	420	480	500	500

• All parameters in the table are given in mm.