M4 Serrated Lock Washer, Form A (External Teeth), DIN 6798

The M4 serrated lock washer (DIN 6798, form A, external teeth) is 0.5 mm thick, with a 4.3 mm hole and an outside diameter of 8 mm. It has 11 teeth. It sits under M4 screw heads and nuts; here as simplified STEP files.

How these parts are made, and what the levels mean: read the method

• Also searched as: M4 washer
• Model id: din6798-a-m4
• Standard: DIN 6798:1988 · size M4

Files

Part key	Simplified
din6798-a-m4	STEP

Dimensions

Symbol	Name	min	nom	max	Modeled	Rule	Level
d1	Inside diameter	4.3	4.3	4.48	4.3	nominal	L1
d2	Outside diameter, forms A and J	7.64	8	8	8	nominal	L1
s1	Sheet thickness, forms A and J		0.5		0.5	nominal	L1
teeth_A	Number of teeth, form A	11			11	single limit (min), modeled at the limit	L1

Drawing

As a PDF: CC-DIN6798-SZ-M4.pdf.

Goes with the M4 serrated lock washer

• ISO 4762 socket head cap screw in 10 lengths from 6 to 40 mm, the same size as this M4 form A serrated lock washer: M4 Socket Head Cap Screw (Allen Bolt), ISO 4762 / DIN 912
• ISO 4017 hex head screw in 9 lengths from 8 to 40 mm, the same size as this M4 form A serrated lock washer: M4 Hex Head Screw (Hex Bolt), ISO 4017
• ISO 4032 hex nut, the same size as this M4 form A serrated lock washer: M4 Hex Nut (Hexagon Nut), ISO 4032 / DIN 934

The M4 form A serrated lock washer beside the M3 and the M5

The M4 is number 4, counting from the smallest, of the 7 DIN 6798 serrated lock washers published here, from M2 to M8.

• Inside diameter (d1): 4.3 mm on the M4 form A serrated lock washer, against 3.2 mm on the M3 and 5.3 mm on the M5.
• Outside diameter (d2): 8 mm on the M4 form A serrated lock washer, against 6 mm on the M3 and 10 mm on the M5.
• Sheet thickness (s1): 0.5 mm on the M4 form A serrated lock washer, against 0.4 mm on the M3 and 0.6 mm on the M5.
• Number of teeth (teeth_A): at least 11 on the M4 form A serrated lock washer, against at least 9 on the M3 and at least 11 on the M5.

The M4 form A serrated lock washer in its other forms

• M4 Serrated Lock Washer, Form J (Internal Teeth), DIN 6798: number of teeth at least 8.
• M4 Serrated Lock Washer, Form V (Countersunk), DIN 6798: sheet thickness 0.25 mm, number of teeth at least 14.

Other sizes

• One size smaller: M3 Serrated Lock Washer, Form A (External Teeth), DIN 6798, 3.2 mm hole, 6 mm OD.
• One size larger: M5 Serrated Lock Washer, Form A (External Teeth), DIN 6798, 5.3 mm hole, 10 mm OD.

Documents

• CC-DIN6798-DS-M4.pdf: M4 datasheet: values with levels, sources
• CC-DIN6798-SZ-M4.pdf: M4 drawing: this size's values on the views
• parts.json: the part record of this size (the platform contract)

Sources

bossard-bn786, engineersedge-din6798, fasten-it-din6798, globalfastener-din6798-a, globalfastener-din6798-j, globalfastener-din6798-v. Full citations: the method page and this size's datasheet.

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