Westfield Fasteners Product Specification:

DIN 571 - Coach Screws

This product guide contains the specification for metric sized coach screws, a standard part available in various materials from Westfield Fasteners. The basis of this specification is the DIN standard DIN 571.

Product Description

Coach screws are a heavy duty wood screw featuring a hexagonal head. Available in a broad range of sizes for use in projects of varying scale.

Scope of the DIN standard.

DIN 571 specifies the form, dimensions and tolerances for these hexagon head coach screws. It covers sizes from 4mm thread diameter up to and including 20mm. Table 1 below defines the overall dimensions and tolerances of these coach screws. Table 2 defines the tolerance on the shank length.

Thread Size		4	5	6	7	8	10	12	16	20
d_s	max	4.00	5.00	6.00	7.00	8.00	10.00	12.00	16.00	20.00
d_s	min	3.52	4.52	5.52	6.42	7.42	9.42	11.30	15.30	19.30
d_a	max	5	6	7.2	8.2	10.2	12.2	15.2	19.2	24.4
k	nom	2.8	3.5	4	5	5.5	7	8	10	13
	max	3.10	6.88	4.38	5.38	5.88	7.45	8.45	10.45	13.90
	min	2.50	3.13	3.63	4.63	5.13	6.55	7.55	9.55	12.10
s	nom	7	8	10	12	13	17	19	24	30
	max	7.00	8.00	10.00	12.00	13.00	17.00	19.00	24.00	30.00
	min	6.64	7.64	9.64	11.57	12.57	16.57	18.48	23.16	29.16
e	min	7.50	8.63	10.89	13.07	14.2	18.72	20.88	26.17	32.95

Shank Length	+/-
16	0.90
20-30	1.05
35-50	1.25
55-80	1.50
90-120	1.75
130-180	2.00
190-200	2.30

DIN 571 - Coach Screws

Figure 1: DIN 571 Coach Screw

Notes to figure 1:

Table 1: Dimensions & Tolerances according to DIN 571 (mm)

Table 2: Shank Length Tolerance according to DIN 571 (mm)