ISO 2009 : Slotted Countersunk Head Screws

Equivalent Standards

ISO 2009 International Standard specifies the characteristics of slotted countersunk flat head screws of product grade A and with threads from M1,6 to M10 inclusive.

Dimensions

The shank diameter is approximately equal to the pitch diameter or equal to the permissible major thread diameter

ISO 2009 : Slotted Countersunk Head Screws

Thread (d) M1.6 M2 M2.5 M3 (M3.5)1) M4 M5 M6 M8 M10
p2) 0.35 0.4 0.45 0.5 0.6 0.7 0.8 1 1.25 1.5
a max. 0.7 0.8 0.9 1 1.2 1.4 1.6 2 2.5 3
b min. 25 25 25 25 38 38 38 38 38 38
dk3) theoretical max 3.6 4.4 5.5 6.3 8.2 9.4 10.4 12.6 17.3 20
actual nom. = max. 3.0 3.8 4.7 5.5 7.30 8.40 9.30 11.30 15.80 18.30
min. 2.7 3.5 4.4 5.2 6.94 8.04 8.94 10.87 15.37 17.78
k3 nom. = max. 1 1.2 1.5 1.65 2.35 2.7 2.7 3.3 4.65 5
n nom. 0.4 0.5 0.6 0.8 1 1.2 1.2 1.6 2 2.5
max. 0.60 0.70 0.80 1.00 1.20 1.51 1.51 1.91 2.31 2.81
min. 0.46 0.56 0.66 0.86 1.06 1.26 1.26 1.66 2.06 2.56
r max. 0.4 0.5 0.6 0.8 0.9 1 1.3 1.5 2 2.5
t max. 0.50 0.6 0.75 0.85 1.2 1.3 1.4 1.6 2.3 2.6
min. 0.32 0.4 0.50 0.60 0.9 1.0 1.1 1.2 1.8 2.0
x max. 0.9 1 1.1 1.25 1.5 1.75 2 2.5 3.2 3.8
nom. l 1) 4)
min.		 max. Approximate mass, in kilograms per 1 000 pieces (ρ = 7,85 kg/dm3)
(for information only)
2.5 2.3 2.7 0.053
3 2.8 3.2 0.058 0.101
4 3.76 4.24 0.069 0.119 0.206
5 4.76 5.24 0.081 0.137 0.236 0.335
6 5.76 6.24 0.093 0.152 0.266 0.379 0.633 0.903
8 7.71 8.29 0.116 0.193 0.326 0.467 0.753 1.06 1.48 2.38
10 9.71 10.29 0.139 0.231 0.386 0.555 0.873 1.22 1.72 2.73 5.68
12 11.65 0.162 0.268 0.446 0.643 0.993 1.37 1.96 3.08 6.32 9.54
(14) 13.65 14.35 0.185 0.306 0.507 0.731 1.11 1.53 2.2 3.43 6.96 10.6
16 15.65 16.35 0.208 0343 0.567 0.82 1.23 1.68 2.44 3.78 7.6 11.6
20 19.58 20.42 0.417 0.684 0.996 1.47 2 2.92 4.48 8.88 13.6
25 24.58 25.42 0.838 1.22 1.77 2.39 3.52 5.36 10.5 16.1
30 29.58 30.42 1.44 2.07 2.78 4.12 6.23 12.1 18.7
35 34.5 35.5 2.37 3.17 4.72 7.11 13.7 21.2
40 39.5 40.5 3.56 5.32 7.98 15.3 23.7
45 44.5 45.5 5.92 8.86 16.9 26.2
50 49.5 50.5 6.52 9.73 18.5 28.8
(55) 54.05 55.95 10.6 20.1 31.3
60 59.05 60.95 11.5 21.7 33.8
(65) 64.05 65.95 23.3 36.3
70 69.05 70.95 24.9 38.9
(75) 74.05 75.95 26.5 41.4
80 79.05 80.95 28.1 43.9

1) Sizes in parentheses should be avoided if possible
2) P is the pitch of the thread.
3) See ISO 7721.
4) Screws with nominal lengths above the bold, discontinuous line are threaded up to the head; b = l − (k + a).

Specifications and reference International Standards

Material Steel Stainless Steel Non-ferrous metal
General requirements International Standard ISO 8992
Thread Tolerance 6g
International Standards ISO 261, ISO 965-2
Mechanical Properties Property class 4.8, 5.8 A2-50, A2-70 ...
International Standards ISO 898-1 ISO 3506 ISO 8839
Tolerance Product grade A
International Standards ISO 4759-1
Finish Plain

Requirements for electroplating are covered in ISO 4042

If different electroplsting requirements are dsired or if requirements are needed for other finishes, they shall be agreeed between customer and supplier.

Limits for surface discontinuous are cover in ISO 6157-1
Acceptability Acceptance procedure is covered in ISO 3269

Designation

Example of designation: A slotted countersunk flat hjead screw with thread M5, nomial length l = 20 mm and property class 4.8 is designated as follows:

Countersunk flat head screw ISO 2009 - M5 x 20 - 4.8

Reference Documents

ISO 225: 1983, Fasteners-- Bolts, screws, studs and nuts -- Symbol and designation of dimensions.

ISO 261: 1973, ISO general purpose metric screw threads -- General plan

ISO 888: 1976, Bolts screws and nuts- Nominal lengths, and thread lengths for general purpose bolts.

ISO 898-1: 1988, Mechanical properties of fasteners - Part 1: Bolts, screws and studs.

ISO 965-2: 1980, ISO general purpose metric screw threads - Tolerantes - Part 2: Limits of sizes for general purpose bolt and nut threads - Medium quality.

ISO 3269: 1988, Fasteners - Acceptance inspection.

ISO 3506:1979, orrosion-resistant stainless steel fasteners - Specifications.

ISO 4042:1989, Threaded components - Electroplated coating.

ISO 4759-1:1978, Tolerantes for fasteners - Part 1: Bolts, screws and nuts with thread diameters between 1,6 (inclusive) and 150 mm (inclusive) and product grades A, B and C

ISO 6157-1:1988, Fasteners - Surface discontinuities - Part 1: Bolts, screws and studs for general requirements.

ISO 4042:1983, Countersunk head screws - Head configuration and gauging.

ISO 8839:1986, Mechanical properties of fasteners - Bolts, screws, studs and nuts made of non-ferrous metals.

ISO 8992:1986, Fasteners - General requirements for bolts, screws, studs and nuts.