Outer Serrated Lock Washer

The Outer serrated Lock washer produced by Xiaoguo® factory has excellent shock resistance and anti-loosening performance. When used, the external teeth will be embedded into the head of the bolt and the surface of the workpiece, thereby preventing the bolt from loosening.

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Product Description

Outer serrated Lock washer are anti-loosening gaskets with teeth around the outer edge. The teeth stretch out radially from the outer circle of the washer.

When you tighten bolts or nuts, these outer teeth grip onto the surface of the part. It increases friction and forms a mechanical lock, so the fastener won’t come loose easily.

Compared with internal tooth lock washers, the external tooth style fits better for parts with a larger outer size. It spreads pressure evenly and delivers steady locking effect. The internal tooth gasket is mainly used under the heads of smaller screws, while the Outer serrated Lock washer is mainly used under the nuts or for fasteners with larger heads.

Working principle

Outer Serrated Lock Washer

The working principle of the Outer serrated Lock washer is actually quite simple. It mainly relies on two things：

（1）The teeth dig right into the contact surface.

This kind of washer has a circle of sharp teeth on its outer edge. When you tighten bolts or nuts, the teeth get pressed into two touching surfaces:the bottom of the bolt head or nut,and the surface of the installed part.

After the teeth sink in, it works like a ring of barbs under the fastener. If the bolt starts to turn loose naturally, these teeth hold it tight and stop it from spinning.

（2）The washer itself provides elasticity.

The Outer serrated Lock washer is not completely flat; it has a certain degree of elasticity on its own. After being tightened, it is flattened, but the material always wants to return to its original shape, so it continuously exerts an upward force. This force increases the friction between the threads, making the screw less likely to come loose.

Outer Serrated Lock Washer

Size		1.7	2.2	2.7	3.2	3.7	4.3	5.3	6.4	7.4	8.4
d	min=nominal size	1.7	2.2	2.7	3.2	3.7	4.3	5.3	6.4	7.4	8.4
d	max	1.84	2.34	2.84	3.38	3.88	4.48	5.48	6.62	7.62	8.62
dc	max=nominal size	3.6	4.5	5.5	6	7	8	10	11	12.5	15
dc	min	3.3	4.2	5.2	5.7	6.64	7.64	9.64	10.57	12.07	14.57
	t	0.3	0.3	0.4	0.4	0.5	0.5	0.6	0.7	0.8	0.8
Number of Teeth	min	9	9	9	9	10	11	11	12	14	14
per 1000 unitsskg		0.02	0.03	0.045	0.06	0.11	0.14	0.28	0.36	0.5	0.8
For Nominal Thread Diameter		M1.6	M2	M2.5	M3	M3.5	M4	M5	M6	M7	M8

Size		10.5	13	15	17	19	21	23	25	28	31
d	min=nominal size	10.5	13	15	17	19	21	23	25	28	31
d	max	10.77	13.27	15.27	17.27	19.33	21.33	23.33	25.33	28.33	31.39
de	max=nominal size	18	20.5	24	26	30	33	36	38	44	48
de	min	17.57	19.98	23.48	25.48	29.48	32.38	35.38	37.38	43.38	47.38
	t	0.9	1	1	1.2	1.4	1.4	1.5	1.5	1.6	1.6
Number of Teeth	min	16	16	18	18	18	20	20	20	22	22
per 1000 unitsskg		1.25	1.6	2.3	2.9	5	6	7.5	8	12	14
For Nominal Thread Diameter		M10	M12	M14	M16	M18	M20	M22	M24	M27	M30

（1）What is the difference between Outer serrated Lock washer and internal tooth lock washers?

External tooth version:Teeth are arranged on the outer circle, fits fasteners with relatively big heads.

Internal tooth version:Teeth are on the inner circle, with a plain smooth outer edge. This style matches screws with small heads perfectly.

（2）Do you provide samples for testing?

Yes. Standard-sized inventory samples are free of charge (shipping cost is borne by the customer), and the delivery time is 2–5 days.

（3）What is the MOQ and lead time for bulk order?

For standard specifications, the MOQ is generally 1,000 - 5,000 pieces per specification. The delivery time is approximately 15 - 25 days. Stainless steel or Dacromet coating may take a little longer.