1/4" 1/2" 3/4" 3/8" 5/8" 5/16" Metal Black Oxide Flat Washers M2 M2.5 M3 M3.5 M4 M5 DIN 9021

1/4" 1/2" 3/4" 3/8" 5/8" 5/16" Metal Black Oxide Flat Washers M2 M2.5 M3 M3.5 M4 M5 DIN 9021 
Description
 
Typical size
 
#10 black flat washer
1/4 black flat washers
3/8 black flat washer
5/16 black flat washers
 
Washers often get thrown to the side or made into a game, but these unimpressive metal circles are more important than they are given credit for. They keep other fasteners in place against vibrations and impact. They keep surfaces from slipping against one another. we have a selection of Black Oxide Stainless Steel Washers to blend with dark-colored projects. Our washers are all weather resistant and high quality.
The washer size to be used with a particular screw size is determined by the first number in the screw size.
For example, a 4-40 machine screw and a #4 sheet metal have about the same major thread diameter and require a #4 washer, flat or lock.
A washer is normally used to distribute the load of a threaded fastener, such as a screw or nut. Other uses are as a spacer, a wear pad, preload indicating device, locking device, and to reduce vibration.
Washers are also important for preventing galvanic corrosion, particularly by insulating steel screws from aluminium surfaces.
To complement our range of fixtures and fittings, we have sourced a range of industrial black oxide washers. These come in a variety of sizes to suit various application such as furniture construction, woodworking projects, lighting design and any general vintage industrial project.
These flat washers will create a more authentic appearance for your project.
 
Thick Washer, Flat Washer Type Standard, Material Steel, Material Grade/Class Grade 5, Finish Black Oxide, For Screw Size #10, Inside Diameter 0.203 in, Outside Diameter 1/2 in, Maximum Thickness 0.093 in, System of Measurement Inch, Minimum Thickness 0.093 in, Color Black, Inside Diameter Tolerance +/-0.010 in, Outside Diameter Tolerance +/-0.010 in, Pack Size Small Pack, Rockwell Hardness C4, Thickness Tolerance +0.005/-0.004 in, Package Quantity 25
 

Specification

Flat Washer Types

Black or Plain Finish Flat Washers

Flat washers are unfinished or will have a minimally protective finish. Black flat washers offer near zero corrosion resistance, though black oxide coatings or oiled coatings do offer increased corrosion resistance over unfinished flat washers.

Black flat washers are commonly referred to as plain finish, black, black oxide, black phosphate, bare or light oil coated.

Galvanized Flat Washers

Flat washers are coated with a sacrificial zinc coating that acts as an anode to prevent the fastener underneath from corroding.

Hot Dipped Galvanized: Fasteners are dipped in a bath of molten zinc.

Plated Flat Washers

Flat washers are coated with a thin layer of zinc, typically via electroplating.

Plated SAE flat washers will not corrode as quickly when covered with this protective coating, even when a scratch or cut exposes the steel to air or moisture. Zinc or cadmium plating acts as a sacrificial anode, and will always tarnish and corrode first thereby protecting the steel underneath.

Teflon or PTFE Coated Flat Washers

Flat washers have a PTFE coating (commonly referred to as the Dupont tradename Teflon Flat Washers) and are formulated with superior characteristics for maximum fastener life.

Technical components include a tensile strength of up to 4,000 psi and an operating pressure up to 100,000 psi. The absence of thread locking oxides enable easy and safe fastener removal. PTFE coatings have extreme chemical resistance and are ideal for applications including insulating piping, boiler rooms, water filled piping, water lines and more.