Bronze Lock Washers | McMaster-Carr

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Material

Bronze

Phosphor Bronze

Silicon Bronze

System of Measurement

Screw Size

Washer Type

Tooth Location

Thickness

Performance

Highly Corrosion Resistant

Specifications Met

Hardness

DFARS Specialty Metals

REACH

RoHS

U.S.–Mexico–Canada Agreement (USMCA) Qualifying

Yes

Export Control Classification Number (ECCN)

EAR99

Military Specification

Overall Height

Height

Number of Waves

73 Products

Washer Type

Split

Stop nuts and screws from loosening due to light vibration

24 products

Tooth

Grip better than split lock washers in applications with constant movement

42 products

Washer Type

Wave

Keep bolted assemblies secure on slightly uneven surfaces

7 products

Performance

Reusable

Switch between assemblies without losing strength

7 products

Split Lock Washers

Stop nuts and screws from loosening due to mild vibration. As you tighten, the uneven ends bite into the nut or screw so it won't back out. While they're not as vibration resistant as other lock washers, they are a great fit for electrical panels, light fixtures, and other light duty assemblies. Split lock washers are not reusable, and they only work with fasteners that have right-hand threads.

Highly Corrosion-Resistant Silicon Bronze—The choice for marine environments, these washers won't rust or deteriorate when submerged in salt water. They resist corrosion as well as 316 stainless steel, but are not quite as strong.

	ID	OD	Thk.	Specs. Met	Pkg. Qty.		Pkg.
Highly Corrosion-Resistant Silicon Bronze



	No. 2	0.094"	0.172"	0.020"	ASME B18.21.1	100	93496A403	00000


	No. 3	0.107"	0.195"	0.025"	ASME B18.21.1	100	93496A404	0000
	No. 4	0.120"	0.209"	0.025"	ASME B18.21.1	100	93496A405	0000
	No. 4	0.120"	0.209"	0.025"	ASME B18.21.1	1,000	93496A005	00000
	No. 6	0.148"	0.250"	0.031"	ASME B18.21.1	100	93496A407	0000
	No. 6	0.148"	0.250"	0.031"	ASME B18.21.1	1,000	93496A007	00000
	No. 8	0.174"	0.293"	0.040"	ASME B18.21.1	100	93496A409	0000
	No. 8	0.174"	0.293"	0.040"	ASME B18.21.1	1,000	93496A009	00000
	No. 10	0.200"	0.334"	0.047"	ASME B18.21.1	100	93496A415	0000
	No. 12	0.227"	0.377"	0.056"	ASME B18.21.1	100	93496A418	00000
	1/4"	0.260"	0.487"	0.062"	ASME B18.21.1	100	93496A029	00000


	5/16"	0.322"	0.583"	0.078"	ASME B18.21.1	50	93496A030	00000
	3/8"	0.385"	0.680"	0.094"	ASME B18.21.1	25	93496A031	00000
	7/16"	0.450"	0.776"	0.109"	ASME B18.21.1	10	93496A432	0000
	1/2"	0.512"	0.869"	0.125"	ASME B18.21.1	10	93496A433	0000
	5/8"	0.641"	1.073"	0.156"	ASME B18.21.1	5	93496A435	0000
	3/4"	0.766"	1.265"	0.188"	ASME B18.21.1	5	93496A436	00000
	1"	1.024"	1.656"	0.250"	ASME B18.21.1	5	93496A445	00000
	M3	3.4 mm	6.2 mm	0.7 mm to 0.9 mm	DIN 127B	100	97093A201	00000
	M4	4.4 mm	7.6 mm	0.8 mm to 1.0 mm	DIN 127B	100	97093A202	00000
	M5	5.4 mm	9.2 mm	1.1 mm to 1.3 mm	DIN 127B	100	97093A203	00000


	M6	6.5 mm	11.8 mm	1.5 mm to 1.7 mm	DIN 127B	50	97093A204	00000
	M8	8.5 mm	14.8 mm	1.9 mm to 2.1 mm	DIN 127B	25	97093A205	00000
	M10	10.7 mm	18.1 mm	2.0 mm to 2.4 mm	DIN 127B	10	97093A206	0000

Tooth Lock Washers

Grip tighter than split lock washers to prevent nuts and screws from loosening in applications with constant movement, such as conveyors. Tooth lock washers typically can't be reused because the teeth often get bent when tightened.

External Tooth

Teeth on the outside edge bite into both the fastener and the mating surface for a stronger hold than internal-tooth lock washers. However, they may mar your material and snag on objects. Pair these washers with nuts and screws that are large enough to make contact with the teeth, such as pan, button, and binding head screws.

Highly 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.

	ID	OD	Thk.	Specs. Met	Pkg. Qty.		Pkg.
Highly Corrosion-Resistant Phosphor Bronze



	No. 3	0.102"	0.235"	0.010" to 0.016"	ASME B18.21.1	100	92164A333	00000


	No. 4	0.115"	0.260"	0.012" to 0.018"	ASME B18.21.1	100	92164A005	0000
	No. 6	0.141"	0.320"	0.016" to 0.022"	ASME B18.21.1	100	92164A007	0000
	No. 8	0.168"	0.381"	0.018" to 0.023"	ASME B18.21.1	100	92164A009	0000
	No. 10	0.195"	0.410"	0.018" to 0.024"	ASME B18.21.1	100	92164A011	0000
	No. 12	0.221"	0.475"	0.020" to 0.027"	ASME B18.21.1	100	92164A334	0000
	1/4"	0.256"	0.510"	0.023" to 0.028"	ASME B18.21.1	100	92164A029	00000
	5/16"	0.320"	0.610"	0.028" to 0.034"	ASME B18.21.1	50	92164A030	0000
	3/8"	0.384"	0.694"	0.032" to 0.040"	ASME B18.21.1	25	92164A031	0000
	7/16"	0.448"	0.760"	0.032" to 0.040"	ASME B18.21.1	25	92164A032	0000
	1/2"	0.513"	0.900"	0.037" to 0.045"	ASME B18.21.1	25	92164A033	00000


	5/8"	0.641"	1.070"	0.042" to 0.050"	ASME B18.21.1	10	92164A040	00000
	3/4"	0.768"	1.260"	0.047" to 0.055"	ASME B18.21.1	5	92164A335	0000

Internal Tooth

Internal teeth dig into the nut or screw to prevent it from backing out. Unlike external-tooth lock washers, these have a smooth outside edge, so they are less likely to mar your material or snag on objects. However, they don’t grip quite as well. Pair them with fasteners that have small diameters, such as fillister and cheese head screws.

	ID	OD	Thk.	Specs. Met	Pkg. Qty.		Pkg.
Highly Corrosion-Resistant Phosphor Bronze



	No. 2	0.089"	0.200"	0.010" to 0.016"	ASME B18.21.1	100	92165A002	00000


	No. 3	0.109"	0.232"	0.010" to 0.016"	ASME B18.21.1	100	92165A121	0000
	No. 4	0.115"	0.270"	0.012" to 0.018"	ASME B18.21.1	100	92165A005	0000
	No. 5	0.136"	0.280"	0.014" to 0.018"	ASME B18.21.1	100	92165A122	0000
	No. 6	0.141"	0.295"	0.016" to 0.022"	ASME B18.21.1	100	92165A007	0000
	No. 8	0.168"	0.340"	0.018" to 0.023"	ASME B18.21.1	100	92165A009	0000
	No. 10	0.195"	0.381"	0.018" to 0.024"	ASME B18.21.1	100	92165A011	0000
	No. 12	0.231"	0.410"	0.020" to 0.027"	ASME B18.21.1	100	92165A123	0000
	1/4"	0.256"	0.478"	0.023" to 0.028"	ASME B18.21.1	100	92165A029	00000
	5/16"	0.320"	0.610"	0.028" to 0.034"	ASME B18.21.1	50	92165A030	0000
	3/8"	0.384"	0.692"	0.032" to 0.040"	ASME B18.21.1	50	92165A031	00000


	7/16"	0.448"	0.789"	0.032" to 0.040"	ASME B18.21.1	25	92165A032	0000
	1/2"	0.512"	0.900"	0.037" to 0.045"	ASME B18.21.1	25	92165A033	00000
	5/8"	0.640"	1.071"	0.042" to 0.050"	ASME B18.21.1	5	92165A055	0000
	3/4"	0.795"	1.245"	0.047" to 0.055"	ASME B18.21.1	5	92165A124	0000

Mil. Spec. Tooth Lock Washers

These washers are manufactured and tested to strict U.S. military standards for material and construction. They resist vibration better than split lock washers to prevent nuts and screws from loosening in applications with constant movement, such as conveyors. Tooth lock washers typically can't be reused because the teeth often get bent when tightened.

External Tooth

	ID	OD	Thk.	Mil. Spec.	Specs. Met	Pkg. Qty.		Pkg.
Highly Corrosion-Resistant Phosphor Bronze



	No. 10	0.195"	0.410"	0.020" to 0.025"	MS35335-88	ASME B18.21.1	25	97775A534	00000


	1/4"	0.256"	0.510"	0.023" to 0.028"	MS35335-89	ASME B18.21.1	10	97775A535	0000
	5/16"	0.320"	0.610"	0.028" to 0.034"	MS35335-90	ASME B18.21.1	10	97775A536	0000
	3/8"	0.384"	0.694"	0.032" to 0.040"	MS35335-91	ASME B18.21.1	10	97775A537	0000
	1/2"	0.513"	0.900"	0.037" to 0.045"	MS35335-93	ASME B18.21.1	10	97775A538	0000

Internal Tooth

	ID	OD	Thk.	Mil. Spec.	Specs. Met	Pkg. Qty.		Pkg.
Highly Corrosion-Resistant Phosphor Bronze



	No. 2	0.089"	0.200"	0.010" to 0.015"	MS35333-103, NASM35333	ASME B18.21.1	25	96551A340	00000


	No. 4	0.115"	0.270"	0.015" to 0.019"	MS35333-104, NASM35333	ASME B18.21.1	25	96551A350	0000
	No. 6	0.141"	0.295"	0.017" to 0.021"	MS35333-105, NASM35333	ASME B18.21.1	25	96551A360	00000
	No. 8	0.168"	0.340"	0.018" to 0.023"	MS35333-106, NASM35333	ASME B18.21.1	25	96551A370	00000
	No. 10	0.195"	0.381"	0.020" to 0.025"	MS35333-107, NASM35333	ASME B18.21.1	25	96551A380	00000
	1/4"	0.256"	0.478"	0.023" to 0.028"	MS35333-108, NASM35333	ASME B18.21.1	25	96551A390	00000
	5/16"	0.332"	0.610"	0.028" to 0.034"	MS35333-109, NASM35333	ASME B18.21.1	10	96551A400	0000
	3/8"	0.384"	0.692"	0.032" to 0.040"	MS35333-110, NASM35333	ASME B18.21.1	10	96551A410	0000
	1/2"	0.512"	0.900"	0.037" to 0.045"	MS35333-113, NASM35333	ASME B18.21.1	5	96551A420	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.

	No. of Waves	ID, mm	OD, mm	Thk., mm	Overall Ht., mm	Specs. Met	Pkg. Qty.		Pkg.
Highly Corrosion-Resistant Phosphor Bronze



	M3	1	3.2	8.0	0.5	1.6	DIN 137B	25	90394A111	000000


	M4	1	4.3	9.0	0.5	2.0	DIN 137B	25	90394A112	00000
	M5	1	5.3	11.0	0.5	2.2	DIN 137B	10	90394A113	0000
	M6	1	6.4	12.0	0.5	2.6	DIN 137B	10	90394A114	0000
	M8	1	8.4	15.0	0.8	3.0	DIN 137B	5	90394A115	0000
	M10	1	10.5	21.0	1.0	4.2	DIN 137B	1	90394A116	0000
	M12	1	13.0	24.0	1.2	5.0	DIN 137B	1	90394A117	0000