DIN 988 Shim Washer

The shim washer DIN 988 has several names. It is called an adjusting washer because this fastener can be used to level the gap between the bolt head and the surface being joined. Another name is “bearing washer”: the product increases the bearing area of the fastening device and thereby protects the base material from damage and deformation.

It is also called a “spacer ring,” since the washer acts as a backing under the head of a threaded fastener or a nut. Its use is especially effective when the working hole is too large for the bolt head. The washer has a closed annular shape with flat working surfaces.

Materials and size range of DIN 988 shim washers

This metal product is manufactured in accordance with the standard’s requirements from various metals. First of all, these are alloy steels with a zinc-plated or chrome-plated coating applied by electroplating.

The next materials are chromium-nickel austenitic steel grades A2 and A4. Stainless steel does not require additional corrosion protection. DIN 988 shim washers made of austenitic alloys hold up well in humid and aggressive environments.

For specific cases, this type of washer is also made of copper, brass, aluminium alloys and engineering plastic. These products are usually used together with other fastening assembly components made of similar materials.

Typical inner diameters of the metal products are 4–20 mm, outer diameters 8–28 mm, thickness from 0.1 mm to 1.0 mm.

Dimensions of the DIN 988 adjusting flat shim washer in mm:

d₁	d₂	h
4	8	0.1
4	8	0.5
4	8	1.0
5	10	0.2
5	10	0.5
5	10	1.0
6	12	0.2
6	12	0.5
6	12	1.0
6.5	16	2.0
8	14	0.2
8	14	0.5
8	14	1.0
9	16	1.0
10	16	0.1
10	16	0.2
10	16	0.5
10	16	1.0
12	18	0.5
12	18	1.0
12.5	20	0.5
14	20	0.5
14	20	1.0
15	22	0.5
15	22	1.0
16	22	0.1
16	22	0.2
16	22	0.3
16	22	1.0
20	28	0.1
20	28	0.5
20	28	1.0

d₁	d₂	h
3	6	0.1; 0.2; 0.3; 0.5
4	8	0.1; 0.2; 0.3; 0.5
5	10	0.1; 0.2; 0.25; 0.3; 0.5; 1
6	12	0.1; 0.2; 0.25; 0.3; 0.5; 1
7	13	0.3; 0.5; 1
8	12	0.5
8	14	0.1; 0.2; 0.25; 0.3; 0.5; 1
9	15	0.1; 0.2; 0.5; 1; 1.2
10	16	0.1; 0.2; 0.25; 0.3; 0.5; 1; 1.5
11	17	1
12	18	0.1; 0.2; 0.25; 0.3; 0.5; 1; 2
13	19	0.1; 0.5; 1
14	20	0.1; 0.2; 0.25; 0.5; 1
15	21	0.1; 0.15; 0.2; 0.3; 0.5; 1; 2
15	22	0.5; 1
16	22	0.1; 0.2; 0.25; 0.5; 1
17	24	0.1; 0.15; 0.2; 0.3; 0.5; 1; 2
18	25	0.1; 0.2; 0.25; 0.3; 0.5; 1
20	28	0.1; 0.15; 0.2; 0.25; 0.3; 0.5; 1; 1.5
20	30	0.5
20	32	0.1; 0.5; 1
22	30	0.1; 0.2; 0.5; 1; 1.5
22	32	0.1; 0.2; 0.3; 0.5; 1
25	35	0.1; 0.2; 0.25; 0.3; 0.5; 1; 1.5
25	36	0.5; 1
26	37	0.1; 0.2; 0.25; 0.5; 1
28	40	0.1; 0.2; 0.25; 0.3; 0.5; 1
30	40	1
30	42	0.1; 0.2; 0.25; 0.3; 0.5; 1; 1.5; 2
32	45	0.1; 0.25; 0.3; 0.5; 1; 1.5; 2
35	45	0.1; 0.2; 0.3; 0.5; 1; 1.5; 2
36	45	1
37	47	0.1; 0.2; 0.25; 0.3; 0.5; 1; 2
40	50	0.1; 0.2; 0.3; 0.5; 1; 1.5; 2
42	52	0.1; 0.2; 0.3; 0.5; 1; 2
45	55	0.1; 0.2; 0.3; 0.5; 1; 2
48	60	0.5; 1
50	62	0.1; 0.2; 0.3; 0.5; 1; 1.5; 2
52	65	0.1; 0.5; 1; 2
55	68	0.1; 0.2; 0.5; 1; 2
56	72	0.1; 0.5; 1
60	75	0.1; 0.3; 0.5; 1; 1.5; 2
63	80	0.1; 0.2; 0.3; 0.5; 1; 2
65	85	0.1; 0.2; 0.5; 2
70	90	0.1; 0.2; 0.3; 0.5; 1
75	95	0.1; 1
80	100	0.1; 0.2; 0.3; 0.5; 1; 2
90	110	0.5; 1; 2
100	120	1; 2

d₁	d₂	h
3	6	1
4	8	1
6	12	1.2
8	14	1.2
10	16	1.2
12	18	1.2
14	20	1.5
15	21	1.5
16	22	1.5
17	24	1.5
18	25	1.5
20	28	2
22	30	2
22	32	2
25	35	2
25	36	2
26	37	2
28	40	2
30	42	2.5
35	45	2.5
37	47	2.5
40	50	2.5
45	55	3
50	62	3
50	63	3
55	68	3
60	75	3
63	80	3
65	85	3.5
70	90	3.5
75	95	3.5
80	100	3.5
90	110	3.5
100	120	3.5
100	125	3.5

d₁	d₂	h
6	12	0.25; 0.5; 1
8	14	0.1; 0.25; 0.5; 1
10	16	0.1; 0.25; 0.5; 1
12	18	0.1; 0.25; 0.5; 1
14	20	1
16	22	0.1; 0.25; 0.5; 1
18	25	1
20	28	0.1; 0.2; 0.25; 0.5; 1; 2
25	35	0.1; 0.2; 0.25; 0.5; 1
30	42	1
40	50	0.2; 0.5; 1