DIN 472 Internal Spring Retaining Ring

The spring retaining ring manufactured to DIN 472 is installed inside a shaft or rod. It is designed to prevent axial displacement of components fixed on the shaft relative to one another. The standard permits manufacture in three product grades: A, B, C.

The eccentric retaining fastener is made as an open ring. The ends of each part terminate in flat lugs with holes needed for installation and removal of the fastener. For correct selection, the ring diameter must match the size of the bore intended for installing the retainer.

Parts marked with a reference to the German standard DIN 472 have equivalents manufactured to the Russian GOST 13943-86. However, fasteners meeting the requirements of different standards, although called equivalents, may differ in geometric parameters and the quality of raw materials.

For this reason, retaining rings should be selected strictly in accordance with the technical documentation for the assembly work. If no such documentation exists, contact FLOK specialists — they will help with the selection.

Design features of DIN 472 retaining rings

The provisions of DIN 472 apply to retaining rings for internal installation on a shaft, known as eccentric rings. This means that the inner and outer circles of the ring are slightly offset relative to one another. This design minimizes clearance during installation on the shaft and also helps the ring withstand higher loads.

Since this type of part is classified as a highly critical fastening element, strict requirements are also placed on the materials used to make it. According to GOST 13943-86, internal retaining rings must be manufactured from special spring steel grades 65G or 60S2A. The surface of the parts is protected against corrosion with a chromium or cadmium coating.

DIN 472 permits the use of alloy and chromium-nickel steel A2 and A4, as well as brass, in the manufacture of retaining rings. Fasteners made of carbon steel are subject to anti-corrosion treatment by electrogalvanic zinc plating, oxidizing, or phosphating.

Details of assembly work using DIN 472 internal retaining rings

The main condition for correct installation of an internal retaining ring is precise selection of the fastener to match the bore size in the shaft. The thickness and width of the retaining ring and the depth of the groove it is designed for are equally important.

DIN 472 spring retaining washers are installed in the internal cavity of the shaft using special tools. The same tools serve to remove the ring during repair work. Fasteners with the appropriate technical characteristics are selected for different operating conditions.

The perimeter of the retaining ring that protrudes from the groove serves as a reliable stop for machine components, protecting them against axial displacement under dynamic loads, vibration, or oscillation. Bearings most often require this kind of protection.

Tools for working with DIN 472 internal spring retaining rings

These are called retaining ring pliers and resemble pliers or combination pliers in appearance. A tool for assembling and disassembling fastening joints with internal retaining fasteners can be identified by its marking: it contains the letter combination IN, where the letter I comes from the English word internal.

The pliers consist of two hinged parts, each with a handle at one end and a jaw at the other. The tool works as follows: the working tips are inserted into the holes in the lugs of the fastener. When the handles are squeezed together, the jaws also come closer, reducing the diameter of the retaining ring. After the retainer is installed in the groove intended for it in the shaft, the ring is released from the pliers and fits tightly inside the shaft.

The market offers a large number of models that differ in manufacturing material, color, design features, and manufacturer brand. In a broader sense, there are only two variants: straight-jaw and bent-jaw.

When choosing a tool, the conditions of the installation process must be taken into account. For work at considerable depth, a tool with long jaws is required. The thickness of the tips, their shape, and the bend angle also matter. It is more convenient to use a universal pliers set with handles and a set of interchangeable tips — such kits are sold in a compact case for storage and transport.

DIN 472 retaining rings for internal installation

FLOK supplies retaining fasteners manufactured in strict accordance with the requirements of DIN 472 and GOST 13943-86.

We work with enterprises, individual entrepreneurs, and private individuals. For questions on the product range, technical specifications, payment, or ordering, please contact us by phone or through the feedback form.

Shaft dimensions				Ring dimensions in free state
d1	d2	m	n	s	d3	amax	∼b	d5min
8	8.4	0.9	0.6	0.8	8.7	2.4	1.1	1
9	9.4	0.9	0.6	0.8	9.8	2.5	1.3	1
10	10.4	1.1	0.6	1	10.8	3.2	1.4	1.2
11	11.4	1.1	0.6	1	11.8	3.3	1.5	1.2
12	12.5	1.1	0.8	1	13	3.4	1.7	1.5
13	13.6	1.1	0.9	1	14.1	3.6	1.8	1.5
14	14.6	1.1	0.9	1	15.1	3.7	1.9	1.7
15	15.7	1.1	1.1	1	16.2	3.7	2	1.7
16	16.8	1.1	1.2	1	17.3	3.8	2	1.7
17	17.8	1.1	1.2	1	18.3	3.9	2.1	1.7
18	19	1.1	1.5	1	19.5	4.1	2.2	2
19	20	1.1	1.5	1	20.5	4.1	2.2	2
20	21	1.1	1.5	1	21.5	4.2	2.3	2
21	22	1.1	1.5	1	22.5	4.2	2.4	2
22	23	1.1	1.5	1	23.5	4.2	2.5	2
23	24.1	1.3	1.8	1.2	24.6	4.2	2.5	2
24	25.2	1.3	1.8	1.2	25.9	4.4	2.6	2
25	26.2	1.3	1.8	1.2	26.9	4.5	2.7	2
26	27.2	1.3	1.8	1.2	27.9	4.7	2.8	2
27	28.4	1.3	2.1	1.2	29.1	4.7	2.9	2