Washer DIN 9021 M4(4,3) polyamide

Enlarged Washer A fastener that has the appearance of a flat disk with a smooth cylindrical hole in the middle, the diameter of which is larger than the diameter of the metric product with which it is used. Materials from which they are made: steel 140, 200.

Scope DIN 9021 is effectively used for joining materials with a soft structure, such as wood, plastic, etc. The people also have the name "rivet washer", which indicates its appropriate use. Also often used with self-tapping screws DIN 571 and threaded studs DIN 975 when installing wooden structures. A characteristic feature of this washer is that the outer diameter is equal to 3rd of the inner diameter, which helps to take these parameters into account during calculations and installation.

Material Polyamide fasteners offer numerous advantages, including corrosion resistance, ensuring reliability in humid conditions, lightweight properties that contribute to reduced construction weight and lower transportation and installation energy requirements. They are also safe to use, as they do not conduct electricity, making them ideal for situations where electrical contact or short circuits need to be avoided. Additionally, polyamide fasteners are known for their flexibility, allowing them to withstand loads without the risk of breaking.

Analogs: GOST 6958-78, ISO 7093-1. ISO 7093-2.