Westfield Fasteners Product Specification:

DIN 434 - Square Taper Washers for U-Sections

This product guide contains the specification for metric sized square taper washers for U-section beams, standard parts available from Westfield Fasteners. The basis of this specification is the DIN standard DIN 434.

Product Description

Square taper washers with a 8% taper angle for use with tapered U-section or C-section beams. These wedge shaped washers have two grooves running across the washer on the top side, to indicate the taper on the reverse. Put against the U-section, the square taper washer will create a flat surface for the bolt head or nut. The washer will also help distribute the load from the fixing point, protect the surrounding surface and help reduce any loosening of the joint.

Scope of the DIN Standard.

DIN 434 specifies the dimensions and materials for square taper washers for use in structural bolting with U-sections, for sizes from M8 to M27. Figure 1 and table 1 below define the overall dimensions and tolerances of these washers.

This standard covers steel washers, the grade being at the manufacturer's discretion. The hardness is between 100-250 HV 10, with the 10 figure referring to a 10kg load.

technical drawing of Square Taper Washers for U-Sections, to DIN 434

Figure 1: Square Taper Washer for U-Sections, to DIN 434

Table 1: Dimensions & Tolerances according to DIN 434 (mm)

Nominal Size	For Threads	d		a			b			e	h			r	t
Nominal Size	For Threads	min=nom	max	nom	min	max	nom	min	max	Auxiliary size	nom	min	max	=	=
9	M8	9	9.36	22	20	24	22	21.35	22.65	2.9	3.8	3.2	4.4	1.6	0.5
11	M10	11	11.43	22	20	24	22	21.35	22.65	2.9	3.8	3.2	4.4	1.6	0.5
13.5	M12	13.5	13.93	26	24	28	30	29.35	30.65	3.7	4.9	3.9	5.9	2	0.7
17.5	M16	17.5	17.93	32	29.5	34.5	36	35.2	36.8	4.45	5.9	4.9	6.9	2.4	0.8
22	M20	22	22.52	40	37.5	42.5	44	43.2	44.8	5.25	7	6	8	2.8	0.9
24	M22	24	24.52	44	41.5	46.5	50	49.2	50.8	6	8	7	9	3.2	1
26	M24	26	26.52	56	53	59	56	55.05	56.95	6.26	8.5	7.3	9.7	3.2	1
30	M27	30	30.52	56	53	59	56	55.05	56.95	6.26	8.5	7.3	9.7	3.2	1

For verification of details and for further information please refer to the relevant DIN standard documents. E&OE