Miniature Screw Size Chart

Dimensions, lengths and head types of slotted head miniature screws.

Fillister Head:

The fillister head has a flat top surface, cylindrical sides and a flat bearing surface.

Fillister head miniature screws
Size
Desig-
nation		 Thds
per
inch		 D
Basic
Major
Dia.
 Fillister Head Dimensions
A
Head
Dia.		 H
Head
Height		 J
Slot
Width
 T
Slot
Depth		 C
Chamfer		 R
Radius
Max Max. Min Max Min Max. Min. Max. Min. Max. Min.
30 UNM 318 0.0118 0.021 0.019 0.012 0.010 0.004 0.003 0.006 0.004 0.002 0.002
35 UNM 282 0.0138 0.023 0.021 0.014 0.012 0.004 0.003 0.007 0.005 0.002 0.002
40 UNM 254 0.0157 0.025 0.023 0.016 0.013 0.005 0.003 0.008 0.006 0.002 0.002
45 UNM 254 0.0177 0.029 0.027 0.018 0.015 0.005 0.003 0.009 0.007 0.002 0.002
50 UNM 203 0.0197 0.033 0.031 0.020 0.017 0.006 0.004 0.010 0.007 0.003 0.002
55 UNM 203 0.0217 0.037 0.035 0.022 0.019 0.006 0.004 0.011 0.008 0.003 0.002
60 UNM 169 0.0236 0.041 0.039 0.025 0.021 0.008 0.005 0.012 0.009 0.004 0.003
70 UNM 145 0.0276 0.045 0.043 0.028 0.024 0.008 0.005 0.014 0.011 0.004 0.003
80 UNM 127 0.0315 0.051 0.049 0.032 0.028 0.010 0.007 0.016 0.012 0.005 0.004
90 UNM 113 0.0354 0.056 0.054 0.036 0.032 0.010 0.007 0.018 0.014 0.005 0.004
100 UNM 102 0.0394 0.062 0.058 0.040 0.035 0.012 0.008 0.020 0.016 0.006 0.005
110 UNM 102 0.0433 0.072 0.068 0.045 0.040 0.012 0.008 0.022 0.018 0.006 0.005
120 UNM 102 0.0472 0.082 0.078 0.050 0.045 0.016 0.012 0.025 0.020 0.008 0.006
140 UNM 85 0.0551 0.092 0.088 0.055 0.050 0.016 0.012 0.028 0.023 0.008 0.006

Pan Head:

The pan head has a flat top surface, cylindrical sides and a flat bearing surface

Pan head miniature screws
Size
Desig-
nation		 Thds
per
inch		 D
Basic
Major
Dia.
 Pan Head Dimensions
A
Head
Dia.		 H
Head
Height		 J
Slot
Width
 T
Slot
Depth		 C
Chamfer		 R
Radius
Max Max. Min Max Min Max. Min. Max. Min. Max. Min.
30 UNM 318 0.0118 0.025 0.023 0.010 0.008 0.005 0.003 0.005 0.003 0.002 0.002
35 UNM 282 0.0138 0.029 0.027 0.011 0.009 0.005 0.003 0.006 0.004 0.002 0.002
40 UNM 254 0.0157 0.033 0.031 0.012 0.010 0.006 0.004 0.006 0.004 0.002 0.002
45 UNM 254 0.0177 0.037 0.035 0.014 0.012 0.006 0.004 0.007 0.005 0.002 0.002
50 UNM 203 0.0197 0.041 0.039 0.016 0.013 0.008 0.005 0.008 0.006 0.003 0.002
55 UNM 203 0.0217 0.045 0.043 0.018 0.015 0.008 0.005 0.009 0.007 0.003 0.002
60 UNM 169 0.0236 0.051 0.049 0.020 0.017 0.010 0.007 0.010 0.007 0.004 0.003
70 UNM 145 0.0276 0.056 0.054 0.022 0.019 0.010 0.007 0.011 0.008 0.004 0.003
80 UNM 127 0.0315 0.062 0.058 0.025 0.021 0.012 0.008 0.012 0.009 0.005 0.004
90 UNM 113 0.0354 0.072 0.068 0.028 0.024 0.012 0.008 0.014 0.011 0.005 0.004
100 UNM 102 0.0394 0.082 0.078 0.032 0.028 0.016 0.012 0.018 0.014 0.006 0.005
110 UNM 102 0.0433 0.092 0.088 0.036 0.032 0.016 0.012 0.018 0.014 0.006 0.005
120 UNM 102 0.0472 0.103 0.097 0.040 0.035 0.020 0.015 0.020 0.016 0.008 0.006
140 UNM 85 0.0551 0.113 0.107 0.045 0.040 0.020 0.015 0.022 0.018 0.008 0.006

Flat Head:

The flat head has a flat top surface and conical bearing surface with an angle of approx. 100 deg.

100-deg flat head miniature screws
Size
Desig-
nation		 Thds
per
inch		 D
Basic
Major
Dia.
 Flat  Head Dimensions
A
Head
Dia.		 Av
Dia. of
Full Cone
 at Max H		 H
Head
Height		 J
Slot
Width
 T
Slot
Depth		 R
Radius
Max Max. Min Max Min Max. Min. Max. Min. Min.
30 UNM 318 0.0118 0.023 0.021 0.0285 0.007 0.005 0.004 0.003 0.004 0.002 0.005
35 UNM 282 0.0138 0.025 0.023 0.0305 0.007 0.005 0.004 0.003 0.004 0.002 0.005
40 UNM 254 0.0157 0.029 0.027 0.0348 0.008 0.006 0.005 0.003 0.005 0.003 0.006
45 UNM 254 0.0177 0.033 0.031 0.0392 0.009 0.007 0.005 0.003 0.005 0.003 0.006
50 UNM 203 0.0197 0.037 0.035 0.0459 0.011 0.008 0.006 0.004 0.006 0.004 0.008
55 UNM 203 0.0217 0.041 0.039 0.0503 0.012 0.009 0.006 0.004 0.006 0.004 0.008
60 UNM 169 0.0236 0.045 0.043 0.0546 0.013 0.010 0.008 0.005 0.008 0.005 0.010
70 UNM 145 0.0276 0.051 0.049 0.0610 0.014 0.011 0.008 0.005 0.008 0.005 0.010
80 UNM 127 0.0315 0.056 0.054 0.0696 0.016 0.012 0.010 0.007 0.010 0.006 0.012
90 UNM 113 0.0354 0.062 0.058 0.0759 0.017 0.013 0.010 0.007 0.010 0.006 0.012
100 UNM 102 0.0394 0.072 0.068 0.0847 0.019 0.015 0.012 0.008 0.012 0.008 0.016
110 UNM 102 0.0433 0.082 0.078 0.0957 0.022 0.018 0.012 0.008 0.012 0.008 0.016
120 UNM 102 0.0472 0.092 0.088 0.1068 0.025 0.020 0.016 0.012 0.016 0.010 0.020
140 UNM 85 0.0551 0.103 0.097 0.1197 0.027 0.022 0.016 0.012 0.016 0.010 0.020

Note 1:The diameter of the unthreaded body shall not be more than the maximum major diameter nor less than the minimum pitch dia. of the thread.

Note 2: For screw lengths four times the major dia. or less, thread length Lt shall extend to within two threads of the head bearing surface. Screws of greater length shall have complete threads for a minimum of four major diameters.

 

Supplements:

Reference:

  • ASME B18.11-2000 : Miniature Screws