Reduced washer

Washer DIN 433 is a reduced or narrow washer, distinguished from standard size ranges by its small thickness. The shape is flat, ring-shaped, and convenient to use.

The wide size range allows the fastener to be used with practically any type of threaded fastener.

The washer is used as a backing under the heads of bolts, screws, self-tapping screws, studs, and is installed together with nuts.

The product is used where it is necessary to extend the length of the fastening, protect the surface of the bearing area on the joined elements, and add extra strength to the fastener assembly.

Main characteristics of DIN 433 reduced washers

The technical properties of the washer, as well as its scope of use, are governed by the German standard DIN 433. This is not the only document to which these products are manufactured. Some manufacturers follow the Russian GOST 10450-78 and the European ISO 7092 when producing narrow washers.

The quality passports for these products, as well as the marking, reference the stated regulatory documents. And although they are called equivalents of DIN 433, minor differences in geometric parameters may still be present. To avoid errors when installing the fastener, check the parameters with FLOK specialists.

In accordance with the standard’s recommendations, reduced washers are made of hardened steel with galvanic or mechanical zinc plating, as well as with a nickel or chrome coating applied by electroplating. A separate group consists of hardware made of brass and stainless steel grades A2 and A4. The latter have high resistance to acids and alkalis and can serve for many years in seawater. Sometimes narrow washers are made of durable technical plastic.

Where and how the DIN 433 reduced washer is used

The installation method for narrow washers does not differ from that of fasteners of other categories. After selecting the required size, the washer is placed on the shank of the threaded fastener or positioned under the nut. The washer increases the bearing area of the fastener and prevents the base material from being crushed while the bolt is tightened.

Thanks to the metal backing, the risk of the fastener spontaneously loosening is reduced. Electricians make use of this property in their practical work.

Metal reduced washers are used in construction, in the assembly of machines, mechanisms and machine tools. They are used in the petrochemical and mining industries. Products made of non-ferrous metals are used in instrument making and in the medical and food industries.

FLOK supplies reduced washers DIN 433 in the full size range and in the listed materials.

Dimensions of the DIN 433 standard washer, in mm

d	d1	d2	s
M6	6.4	11.0	1.6
M8	8.4	15.0	1.6
M10	10.5	18.0	1.6
M12	13.0	20.0	2.0
M16	17.0	28.0	2.5