7/16" Internal Tooth Lock Washer

The material of the 7/16" Internal Tooth Lock Washer directly affects the core performance of the product such as anti-loosening, conductivity, and corrosion resistance. For different usage scenarios, it is necessary to select the most suitable combination of base material and surface treatment.

（1）Carbon steel / Spring steel

Core Performance:High strength, excellent elasticity, strong biting force, and stable anti-loosening effect

Applicable environment:General industrial environment, suitable for 8.8 grade and below bolts that can withstand high preload forces

（2）Stainless steel

A2 (304)

Core Performance:General corrosion resistance, excellent comprehensive performance, and high cost-effectiveness.

Applicable environment:The 304 stainless steel 7/16" Internal Tooth Lock Washer is suitable for use in food, medical, and outdoor humid environments. It can be selected in AW or IOW specifications and has a greater load-bearing capacity.

A4 (316)

Core Performance:Contains molybdenum and has excellent resistance to chloride ion corrosion.

Applicable environment:Coastline, high temperature, and environment with highly corrosive chemicals

（3）Phosphor bronze

Core Performance:Conductive, non-magnetic, and does not produce sparks

Applicable environment:Electrical grounding, connectors, military industry, oil and gas, and other explosion-proof environments or occasions where magnetic sensitivity is required

（4）Copper

Core Performance:Excellent electrical and thermal conductivity

Applicable environment:The areas in electrical and electronic equipment where conductive contact or heat dissipation connections are required

（5）Aluminum alloy

Core Performance:Lightweight and corrosion-resistant

Applicable environment:Aerospace, lightweight equipment or designs that are sensitive to weight

M2	2.2	2.34	4.20	4.5	0.28	0.32
M2.5	2.7	2.84	5.20	5.5	0.37	0.43
M3	3.2	3.38	5.70	6.0	0.37	0.43
M3.5	3.7	3.88	6.64	7.0	0.47	0.53
M4	4.3	4.48	7.64	8.0	0.47	0.53
M5	5.3	5.48	9.64	10.0	0.57	0.63
M6	6.4	6.62	10.57	11.0	0.67	0.73
M7	7.4	7.62	12.07	12.5	0.77	0.83
M8	8.4	8.62	14.57	15.0	0.77	0.83
M10	10.5	10.77	17.57	18.0	0.87	0.93
M12	13.0	13.27	19.98	20.5	0.96	1.04
M14	15.0	15.27	23.48	24.0	0.96	1.04
M16	17.0	17.27	25.48	26.0	1.16	1.24
M18	19.0	19.33	29.48	30.0	1.36	1.44
M20	21.0	21.33	32.38	33.0	1.36	1.44
M24	25.0	25.33	37.38	38.0	1.45	1.55
Informtion and drawing Provided are reference only

FAQ

（1）What is the hardness of spring steel 7/16" Internal Tooth Lock Washer?

After heat treatment, the hardness usually reaches HRC 40–50 (approximately HV 400–530).

(2) Can I use 316 stainless steel 7/16" Internal Tooth Lock Washer in marine environments?

Yeah, you can. A4 (316) stainless steel has molybdenum in it, so it stands up well to chloride corrosion – perfect for salt spray conditions like on ships or along the coast.

(3) What surface finish do you recommend for general industrial use?

For general industrial use, we usually suggest galvanized finish – white or yellow zinc. It’s low‑cost and gives you enough rust protection for indoor or light outdoor applications.

(4) Can you provide a material certificate for each batch?

Yes. We include a factory material certificate (Mill Test Certificate) with every shipment. It shows the chemical composition and hardness.