1.20 mm Shims | McMaster-Carr

With a grip that's second only to wedge lock, these washers stop nuts and screws from wiggling loose under constant, vigorous vibration. They are ideal for engines, turbines, generators, and other heavy duty equipment. Similar to a spring, they flatten under pressure to add tension between mating surfaces. As long as the washers aren't deformed or otherwise damaged, you can reuse them indefinitely without losing locking strength. Also known as conical washers and Belleville washers.

Stack multiple washers in the same direction to double or triple how much weight they can bear. Stack washers in opposite directions for better deflection, which means they compress further and withstand more shock and movement without loosening.

18-8 Stainless Steel—The choice for wet and outdoor environments, these washers won't rust when exposed to moisture. However, they can't hold up to the harsh chemicals that 316 stainless steel can.

Super-Corrosion-Resistant 316 Stainless Steel—Superior to 18-8 stainless steel, these washers won't degrade when exposed to harsh weather, salt water, and most chemicals.

High-Strength 17-7 PH Stainless Steel—The strongest stainless steel washers we offer, these are comparable to high-strength Grade 8 steel. They won’t rust in wet and outdoor environments, but they can’t handle the harsh chemicals that 316 stainless steel can.

Zinc-Plated Steel—A common choice for areas with occasional exposure to moisture.

Phosphate-Coated Steel—Paint adheres evenly to the surface of these washers, so you can add your own decorative finish. They are more durable than zinc-plated steel washers to withstand wet and outdoor environments. However, they won't hold up to the harsh chemicals that stainless steel can.

Steel—Best for dry environments since moisture will cause these washers to rust.

DIN 432—These washers have a small tab that presses up against the flats of your nut or screw for extra security.

	ID, mm	OD, mm	Thk., mm	Overall Ht., mm	Specs. Met	Pkg. Qty.		Pkg.
18-8 Stainless Steel


	M5	5.3	11.0	1.2	1.6	DIN 6796	25	000000000	000000

	Super-Corrosion-Resistant 316 Stainless Steel


			M5	5.3	11.0	1.2	1.6	DIN 6796	10	000000000	00000
			M12	13.0	30.0	1.2	4.5	DIN 432	10	000000000	00000
			M14	15.0	33.0	1.2	4.5	DIN 432	5	000000000	00000
			M16	17.0	36.0	1.2	4.5	DIN 432	5	000000000	00000

			High-Strength 17-7 PH Stainless Steel


					M5	5.3	11.0	1.2	1.6	DIN 6796	5	000000000	00000

					Zinc-Plated Steel


							M5	5.3	11.0	1.2	1.6	DIN 6796	50	000000000	0000

							Phosphate-Coated Steel


									M5	5.3	11.0	1.2	1.6	DIN 6796	100	000000000	00000

									Steel


											M5	5.3	11.0	1.2	1.6	DIN 6796	100	000000000	00000
											M12	13.0	30.0	1.2	4.5	DIN 432	5	000000000	00000
											M14	15.0	33.0	1.2	4.5	DIN 432	1	000000000	0000
											M16	17.0	36.0	1.2	4.5	DIN 432	1	000000000	0000

Wave Spring Lock Washers

The wavy shape flexes like a spring to keep nuts and screws secure on slightly uneven surfaces. These washers add a small amount of tension to stop fasteners from backing out due to mild vibration. While they don't hold as well as other lock washers, they do grip slightly better than curved washers. They work best in electrical panels, light fixtures, and other light duty assemblies. Since these washers hold their shape when untightened, you can reuse them a handful of times without losing strength.

Zinc-Plated Steel—A common choice for areas with occasional exposure to moisture.

Black-Oxide Steel—Typically chosen for their appearance, these washers have a dark, matte coating that creates a finished look. They offer minimal corrosion resistance, so they're best for dry environments.

Super-Corrosion-Resistant Phosphor Bronze—Stronger and more wear resistant than silicon bronze, but with the same excellent corrosion resistance. These washers won't rust or deteriorate when submerged in salt water, so they're a good fit for marine environments.

DIN 128B—These washers have split ends that bite into your material surface for a tighter hold than other wave washers.

	No. of Waves	ID, mm	OD, mm	Thk., mm	Overall Ht., mm	Specs. Met	Pkg. Qty.		Pkg.
18-8 Stainless Steel


	M6	1	6.5	11.8	1.2	2.2	DIN 128B	25	000000000	00000
	M12	1	13.0	24.0	1.2	5.0	DIN 137B	10	000000000	0000

	Zinc-Plated Steel


			M6	1	6.1	11.8	1.2	2.0	DIN 128B	100	000000000	00000

			Black-Oxide Steel


					M12	1	13.0	24.0	1.2	5.0	DIN 137B	25	000000000	0000

					Super-Corrosion-Resistant Phosphor Bronze


							M12	1	13.0	24.0	1.2	5.0	DIN 137B	1	000000000	0000

Curved Spring Lock Washers

The curvy, spring-like shape adds a small amount of tension to prevent nuts and screws from backing out due to mild vibration. These washers also flex slightly to compensate for uneven surfaces. While more secure than a standard flat washer, these have the least amount of gripping power of all our lock washers. They are best suited for electrical panels, light fixtures, and other light duty assemblies. These washers hold their shape when untightened, so you can reuse them a handful of times without losing strength.

Zinc-Plated Steel—A common choice for areas with occasional exposure to moisture.

Zinc-Yellow-Chromate-Plated Steel—With the same corrosion resistance as zinc-plated steel, these withstand occasional exposure to moisture.

DIN 128A—These washers have split ends that bite into your material surface for a tighter hold than other curved washers.

	ID, mm	OD, mm	Thk., mm	Overall Ht., mm	Specs. Met	Pkg. Qty.		Pkg.
18-8 Stainless Steel


	M6	6.1	11.8	1.2	2.0	DIN 128A	100	000000000	000000

	Zinc-Plated Steel


			M6	6.1	11.8	1.2	2.0	DIN 128A	100	000000000	00000

			Zinc-Yellow-Chromate-Plated Steel


					M6	6.1	11.8	1.2	2	DIN 128A	100	000000000	0000

					Black-Oxide Steel


							M6	6.1	11.8	1.2	2.0	DIN 128A	50	000000000	0000