Specifications For Set Screws

Raw Materials
-Set screws shall be made of steel conforming to the requirements specified below.
-For property class 45H, other materials may be used provided that the torque test requirements are met.
Property
Class
Material Heat
Treatment
Chemical Composition %
C P
max.
S
max.
max. min.
14H Carbon Steel1)2) - 0.50 - 0.11 0.15
22H Carbon Steel3) Quenched and Tempered 0.50 - 0.05 0.05
33H Carbon Steel3) Quenched and Tempered 0.50 - 0.05 0.05
45H Carbon Steel3)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., phosphorus content 0.11% max., 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
14H 22H 33H 45H
Vickers Hardness HV min. 140 220 330 450
max. 290 300 440 560
Brinell Hardness HB, F=30 D2 min. 133 209 314 428
max. 276 285 418 532
Rockwell
Hardness
HRB min. 75 95  - -
max. 105  - - -
HRC min.  - - 33 45
max.  - 30 44 53
Minimum Height Of Non-decarburized thread zone, E  - 1/2H1 2/3H1 3/4H1
Maximum depth of complete decarburization, G (mm)  - 0.015 0.015 **
Surface Hardness HV 0.3 (max)  - 320 450 580
Set Screw Pitch Diagram

Pitch of the thread P
mm
0.5 0.6 0.7 0.8 1 1.25 1.5 1.75 2 2.5 3 3.5 4
H1 mm 0.307 0.368 0.429 0.491 0.613 0.767 0.920 1.074 1.227 1.534 1.40 2.147 2.454
E

min

mm

Property
Class
22H 0.154 0.184 0.215 0.245 0.307 0.384 0.460 0.537 0.614 0.767 0.920 1.074 1.227
33H 0.205 0.245 0.286 0.327 0.409 0.511 0.613 0.716 0.818 1.023 1.227 1.431 1.636
45H 0.230 0.276 0.322 0.368 0.460 0.575 0.690 0.806 0.920 1.151 1.380 1.610 1.841



Torque Requirements

Nominal Thread Diameter Minimum Length Of Screw For Test (mm) Test Torque
N x m
Flat Point Cup Point Cone Point Dog Point
3 4 4 5 5 0.9
4 5 5 6 6 2.5
5 5 6 8 8 5
6 8 8 8 8 8.5
8 8 10 10 10 20
10 10 12 12 12 40
12 16 16 16 16 65
16 20 20 20 20 160
20 20 25 25 25 310
24 25 30 30 30 520

*All information is strictly informative