|
SOCKET CAP,
SHOULDER, AND SET SCREWS,
HEX AND SPLINE KEYS (INCH SERIES)
ASME B18.3-2003
|
TABLE 5A DIMENSIONS OF HEXAGON AND SPLINE
SOCKET SET SCREWS
|
Nominal Size or
Basic Screw
Diameter
[Note (5)] |
J |
M |
T |
C |
R |
Y |
Nominal
Hexagon
Socket Size
[Note (8)] |
Nominal Number
of Splines
and Spline
Socket Size
[Note (9)] |
Min. Key
Engagement to
Develop
Functional
Capability of Key
[Note (10)] |
Cup and Flat
Point
Diameters
[Note (5)] |
Basic
Oval Point
Radius
[Note (6)] |
Cone Point
Angle 90 deg
+ 2 deg for
These Nominal
Lengths
or Longer:
118 + 2 deg for
Shorter Nominal
Lengths
[Note (5)] |
Hex
Socket,
TH |
Spline
Socket,
TS |
|
Max. |
Min. |
|
0
1
2
3 |
0.0600
0.0730
0.0860
0.0990 |
...
...
...
... |
0.028
0.035
0.035
0.050 |
4
4
4 and 6
4 and 6 |
.033
0.033
0.048
0.048 |
0.050
0.060
0.060
0.070 |
0.026
0.035
0.040
0.040 |
0.033
0.040
0.047
0.054 |
0.027
0.033
0.039
0.045 |
0.045
0.055
0.064
0.074 |
0.09
0.09
0.13
0.13 |
4
5
5
6 |
0.1120
0.1250
0.1250
0.1380 |
...
1/16
1/16
1/16 |
0.050
0.062
0.062
0.062 |
6
4
6
6 |
0.060
0.069
0.072
0.072 |
0.070
0.080
0.080
0.080 |
0.045
0.055
0.055
0.055 |
0.061
0.067
0.067
0.074 |
0.051
0.057
0.057
0.064 |
0.084
0.094
0.094
0.104 |
0.19
0.19
0.19
0.19 |
6
8
10
1/4 |
0.1380
0.1640
0.1900
0.2500 |
1/16
5/64
3/32
1/8 |
0.062
0.078
0.094
0.125 |
4
6
6
6 |
0.076
0.096
0.111
0.145 |
0.080
0.090
0.100
0.125 |
0.055
0.080
0.080
0.125 |
0.074
0.087
0.102
0.132 |
0.064
0.076
0.088
0.118 |
0.104
0.123
0.142
0.188 |
0.19
0.25
0.25
0.31 |
5/16
3/8
7/16
1/2 |
0.3125
0.3750
0.4375
0.5000 |
5/32
3/16
7/32
1/4 |
0.156
0.188
0.219
0.250 |
6
6
6
6 |
0.183
0.216
0.251
0.291 |
0.156
0.188
0.219
0.250 |
0.156
0.188
0.219
0.250 |
0.172
0.212
0.252
0.291 |
0.156
0.194
0.232
0.270 |
0.234
0.281
0.328
0.375 |
0.38
0.44
0.50
0.57 |
|
5/8 |
0.6250 |
5/16 |
0.312 |
6 |
0.372 |
0.312 |
0.312 |
0.371 |
0.347 |
0.469 |
0.75 |
|
Cam-Tech Industries, Inc. only
manufactures up to 5/8" diameter. |
|
* Where both six and four splines
are available, six splines will be supplied unless four splines are
ordered. |
TABLE 5A DIMENSIONS OF HEXAGON AND SPLINE
SOCKET SET SCREWS
|
|
P |
Q |
B |
B1 |
Half Dog Point
[Notes (5), (11)] |
Shortest Optimum
Nominal Length
to Which TH Applies
[Notes (4), (5), (10)] |
Shortest Optimum
Nominal Length
to Which Ts Applies
[Notes (4), (5), (10)] |
|
Diameter |
Length |
Cup
and
Flat
Points |
90 deg
Cone and
Oval
Points |
Half
Dog
Point |
Cup
and
Flat
Points |
90 deg
Cone and
Oval
Points |
Half
Dog
Point |
| Max. |
Min. |
Max. |
Min. |
0.040
0.049
0.057
0.066 |
0.037
0.045
0.053
0.062 |
0.017
0.021
0.024
0.027 |
0.013
0.017
0.020
0.023 |
0.13
0.13
0.13
0.19 |
0.13
0.19
0.19
0.19 |
0.13
0.13
0.19
0.19 |
0.06
0.13
0.13
0.13 |
0.13
0.19
0.19
0.19 |
0.13
0.13
0.19
0.19 |
0.075
0.083
0.083
0.092 |
0.070
0.078
0.078
0.087 |
0.030
0.033
0.033
0.038 |
0.026
0.027
0.027
0.032 |
0.19
0.19
0.19
0.19 |
0.19
0.19
0.19
0.25 |
0.19
0.19
0.19
0.19 |
0.13
0.13
0.13
0.13 |
0.19
0.19
0.19
0.25 |
0.19
0.19
0.19
0.19 |
0.092
0.109
0.127
0.156 |
0.087
0.103
0.120
0.149 |
0.038
0.043
0.049
0.067 |
0.032
0.037
0.041
0.059 |
0.19
0.19
0.19
0.25 |
0.25
0.25
0.25
0.31 |
0.19
0.25
0.25
0.31 |
0.13
0.19
0.19
0.25 |
0.25
0.25
0.25
0.31 |
0.19
0.25
0.25
0.31 |
0.203
0.250
0.297
0.344 |
0.195
0.241
0.287
0.334 |
0.082
0.099
0.114
0.130 |
0.074
0.089
0.104
0.120 |
0.31
0.38
0.44
0.50 |
0.44
0.44
0.63
0.63 |
0.38
0.44
0.50
0.63 |
0.31
0.38
0.44
0.50 |
0.44
0.44
0.63
0.63 |
0.38
0.44
0.50
0.63 |
|
0.469 |
0.456 |
0.164 |
0.148 |
0.63 |
0.88 |
0.88 |
0.63 |
0.88 |
0.88 |
|
Cam-Tech Industries, Inc. only manufactures up to 5/8"
diameter. |
Reprinted from ASME B18.3-2003, by permission
of The American Society of Mechanical Engineers. All rights reserved.
SOCKET CAP, SHOULDER, AND SET
SCREWS,
HEX AND SPLINE KEYS (INCH SERIES)
ASME B18.3-2003
Table 5A Dimensions of Hexagon and Spline Socket Set Screws (Cont'd)
GENERAL NOTE: For additional
requirements, refer to Notes (4) through (17) and section 2, General Data, of
this Standard.
NOTES:
(1) Nominal Size. Where specifying nominal
size in decimals, zeros preceding decimal and in the fourth decimal place shall
be omitted.
(2) Length. The length of the screw shall be measured overall, parallel to the
axis of the screw. The basic length dimension on the product shall be the
nominal length expressed as a two-place decimal.
(3) Standard Lengths. Standard length increments for set screws shall be as
tabulated below.
| Nominal Screw
Length |
Standard Length
Increment |
| 0.13 through 0.19 [Note (1)] |
0.03 |
| 0.13 through 0.50 |
0.06 |
| 0.50 through 1.00 |
0.13 |
| 1.00 through 2.00 |
0.25 |
| 2.00 through 6.00 |
0.50 |
| Over 6.00 |
1.00 |
NOTE:
*A nominal screw length of 0.13 through 0.19 is applicable only to
nominal sizes 0 (0.060 in.) through 3 (0.099 in.), inclusive.
(4) Face. The plane of the face on the
socket end of the screw shall be approximately normal to the axis of the screw,
and shall be chamfered on screws longer than lengths listed in this Table,
columns B and B1. The chamfer angle V shall be between 30
deg and 45 deg. The chamfer shall extend slightly below the root diameter of
the thread and the edge between flat and chamfer may be slightly rounded. For
screws equal to or shorter than the lengths listed in thisTable, columns B
and B1, or screws 0.250 in. diameter or greater, with a national coarse
thread, including lengths longer than listed in the Table, column B and
B1, chamfering shall be at the option of the manufacturer. If chamfered,
the chamfer angle V shall not exceed 45 deg.
(5) Point Angles. Point angles specified shall apply only to
those portions of the angles that lie below the root diameter of the thread.
The angles may vary in the threaded portions due to manufacturing processes.
W shall be 45 deg, +5 deg -0 deg, for screws of lengths equal to or
longer than the lengths list in the Table, columns B an B1, and 30
deg minimum for shorter screws.
(6) Oval Point Radius Tolerance. The tolerance shall be
+0.015 in. for screw nominal sizes through 5 (0.125 in.) and +0.031 in. for
screw nominal sizes 6 (0.138 in.) and larger.
(7) Cone Point Configuration. The apex of the cone may be
flatted or rounded to the extent of 10% of the basic diameter of the screw.
(8) Hexagon Sockets. See Table 6 for hexagon socket
dimensions and Mandatory Appendix I for gaging of hexagon sockets.
(9) Spline Sockets. See Table 7 for spline socket dimensions
and Mandatory Appendix I for gaging of spline sockets.
(10) Socket Depths. The key engagement dimensions given in
columns TH and TS of this Table shall apply only to nominal screw
lengths equal to or longer than the lengths listed in the Table, columns B
and B1, respectively. For hexagon socket key engagement dimensions in
screws of shorter nominal lengths than those listed in column B of this
Table, see Table 5B. Spline sockets in screws shorter than those listed in
column B1 of this Table, shall be as deep as practicable.
(11) Half Dog Point Runout. The runout of the half dog point
shall not exceed 3% of the nominal size and shall not exceed 0.010 FIM for
nominal sizes up to and including 3/4 in. diameter and 0.020 FIM for nominal
sizes over 3/4 in. diameter.
Runout is defined as the full indicator movement (FIM) obtained by holding
on the thread major diameter near the half dog point, and rotating the screw 360
deg and indicating on the half dog point diameter.
(12) Where both six and four splines are available, six
splines will be supplied unless four splines are ordered.
(13) Tolerance on Length. Tolerance on length of
set screws shall be as tabulated below.
| Nominal
Screw Length |
Tolerance on
Length |
| Up to 0.63, incl. |
±0.01 |
| Over 0.63 to 2.00, incl. |
±0.02 |
| Over 2.00 to 6.00, incl. |
±0.03 |
| Over 6.00 |
±0.06 |
(14) Threads. Threads shall be Unified
external thread: Class 3A, UNC and UNF Series.
Thread lead deviation is controlled by standard thread gages within a thread
length equal to 1.5 basic thread diameters. When using set screws longer than
1.5 basic diameters in length, the pitch diameter of the set screw may need to
be reduced, or the tapped hole's pitch diameter may need to be increased to
avoid interference during assembly.
For all thread diameters # 5 and smaller, thread acceptability will be based on
System 21, ASME B1.3M.
For all thread diameters # 6 and larger, thread acceptability will be based on
System 22, ASME B1.3M when the set screw thread length has a minimum of 7 pitch
lengths.
For all set screws equal or shorter than 7 pitch lengths, thread acceptability
will be based on System 21, ASME 1313M. The chart below shows the lengths equal
to 7 pitch lengths.
| Threads/in. |
7 Pitch Lengths |
Threads/in. |
7 Pitch Lengths |
|
40
36
32
28
24
20
18
16
14
13 |
0.175
0.194
0.219
0.250
0.292
0.350
0.389
0.437
0.500
0.538 |
12
11
10
9
8
7
6
5
4-1/2 |
0.583
0.636
0.700
0.778
0.875
1.000
1.167
1.400
1.556 |
Class 3A threads do not provide a plating
allowance. When set screws must be plated, they should be manufactured with an
undersized pitch diameter to accommodate the plating. When plated products are
required, it is recommended that they be procured from the manufacturer (see
para. 1.10, Introductory Notes).
When standard socket set screws are plated, thread interference is likely to
occur during assembly.
(15) Material
(a) Steel, Alloy. Socket set screws shall be fabricated from alloy steel and
shall conform in all respects to ASTM F 912.
(b) Steel, Corrosion -Resistant. Socket set screws shall be fabricated from
austenitic corrosion-resistant steel and shall conform in all respects to ASTM F
880.
(16) Flat Point. The plane of the end on the flat
point shall be perpendicular to the axis of the thread within 2 deg obtained by
holding the screw on the major thread diameter near the flat point, and
inspecting on an optical comparator or comparable inspection equipment.
(17) Dimensional Conformance. Socket set screws shall have the
following designated characteristics inspected to ASME
1318.18.2M to Inspection Level C:
(a) threads
(b) minimum key engagement
(c) socket size (gaged)
(d) length
(18) Designation. To promote uniformity and understanding in communications
relating to products conforming to this Standard, it is recommended that Hexagon
and Spline Socket Set Screws be designated in accordance with the following
data, preferably in the sequence shown: (a) product name and point style IJ
designation of the standard (c) nominal size (number, fractional or decimal
equivalent) (d) thread pitch (e) nominal length (fractional or decimal
equivalent) (P material (g) protective finish, if required
EXAMPLES:
Hexagon Socket Set Screw, Cup Point, ASME J 1/4-20 X 1/4, Alloy Steel
Spline Socket Set Screw, Flat Point, ASME J 0.112-40 X 0.125, Alloy Steel, Zinc
Plated. (For plated products,
see para. 1.7, Introductory Notes.)
Hexagon Socket Set Screw, Cup Point, ASME 11318.3, 6-32 x 0.250,
Corrosion-Resistant Steel
For the recommended B18 part identifying numbering system (PIN), see ASME
B18.24.1.
Reprinted from ASME B18.3-2003, by
permission of The American Society of Mechanical Engineers. All rights
reserved.
