Section 10
Useful Information
PROPERTY CLASS DATA
Threaded Fasteners not under Tensile Stresses
Ref: ISO 898/5-1980
This International Standard concerning the mechanical properties of set screws and similar fasteners not under tensile stresses, does not apply to
screws requiring special properties such as: -Specified tensile stresses -Weldability -Corrosion resistance -Ability to withstand
temperatures above plus 300ºC (572ºF) or below minus 50ºC (58ºF)
*Please note: Screws made of free-cutting steel should not be used above plus 250ºC (482ºF)
DESIGNATION SYSTEM: 14 H, 17 H, 22 H, 33 H, 45 H
The numerical part of the symbol represents 1/10 of the minimum Vickers hardness. The letter H of the symbol refers to Vickers hardness.
PROPERTY CLASS 14 H 17 H 22 H 33 H 45 H
VICKERS HARDNESS HV min. 140 170 220 330 450
MATERIAL SPECIFICATIONS:
CHEMICAL COMPOSITIONS %
PROPERTY C P S
MATERIAL HEAT TREATMENT
CLASS
max. min. max. max.
14 H Carbon Steel 1, 2 - 0.50 - 0.11 0.15
17 H Carbon Steel - 0.58 - 0.06 0.15
17 H Free Machine Steel - 0.50 - 0.12 0.34
22 H Carbon Steel 3 Quenched and Tempered 0.50 - 0.05 0.05
33 H Carbon Steel 3 Quenched and Tempered 0.50 - 0.05 0.05
45 H Alloy Steel 3, 4 Quenched and Tempered 0.50 0.19 0.05 0.05
1. Free Cutting Steel may be used with lead content 0.35% max., phosphorous content 0.11% and sulphur content 0.34% max.
2. Case hardening is allowed in the case of square-head set screws.
3. Steel with lead content 0.35% max. may be used.
4. Shall contain one or more of alloying elements: chromium, nickel, molybdenum, vanadium or boron.
MECHANICAL PROPERTIES:
PROPERTY CLASS* DIN 267/4-1975-P.87
MECHANICAL PROPERTIES
14 H 17 H 22 H 33 H 45 H PROPERTY CLASS
Vickers Hardness min. 140 170 220 330 450 OLD NEW
HV max. 290 245 300 440 560 4D 11 H
Brinell Hardness min. 133 162 209 314 428 5D 5S 14 H
HB, F = 30 D² max. 276 233 285 418 532 6G 6S 17 H
min. 75 85 95 - - 8G 22 H
HRB
Rockwell max. 105 - - - -
Hardness min. - - - 33 45
HRC
max. - - 30 44 53
*Classes 14 H, 17 H, 22 H AND 33 H are not for hexagon socket set screws.
HARDNESS TESTS:
Hardness reading for the surface hardness shall be taken on the end of the screw, which will be prepared by slightly grinding or polishing to ensure
reproducible readings. In case of doubt, the Vickers hardness test is decisive for acceptance.
© Copyright Metric & Multistandard Components Corp. 2000 10-1019
