Fine Thread

National Fine Thread Sizes (UNF/UNRF)

Measured in Inches

Nominal Size
Major Diameter
Threads/inch
Basic Pitch Diameter
Minor Diameter
Lead Angle
at Basic Pitch Diameter
Height of Fundamental Triangle
Tensile Stress Area
 
 
 
 
 
(Degrees)
(Min)
 
(square inches)
#0
0.060 80 0.052 0.047 4 23
0.01083
0.002
#1
0.073 72 0.064 0.058 3 57
0.01203
0.003
#2
0.086 64 0.076 0.069 3 45
0.01353
0.004
#3
0.099 56 0.087 0.080 3 43
0.01547
0.005
#4
0.112 48 0.099 0.089 3 51
0.01804
0.007
#5
0.125 44 0.110 0.100 3 45
0.01968
0.008
#6
0.138 40 0.122 0.111 3 44
0.02165
0.010
#8
0.164 36 0.146 0.134 3 28
0.02406
0.015
#10
0.190 32 0.170 0.156 3 21
0.02706
0.020
#12
0.216 28 0.193 0.177 3 22
0.03093
0.026
1/4
0.250 28 0.227 0.211 2 52
0.03093
0.036
5/16
0.313 24 0.285 0.267 2 40
0.03608
0.058
3/8
0.375 24 0.348 0.330 2 11
0.03608
0.088
7/16
0.438 20 0.405 0.383 2 15
0.04330
0.119
1/2
0.500 20 0.468 0.446 1 57
0.04330
0.160
9/16
0.563 18 0.526 0.502 1 55
0.04811
0.203
5/8
0.625 18 0.589 0.565 1 43
0.04811
0.256
3/4
0.750 16 0.709 0.682 1 36
0.05413
0.373
7/8
0.875 14 0.829 0.798 1 34
0.06186
0.509
1
1.000 14 0.946 0.903 1 36
0.07217
0.663
1 1/8
1.125 12 1.071 1.035 1 25
0.07217
0.856
1 1/4
1.250 12 1.196 1.160 1 16
0.07217
1.073
1 3/8
1.375 12 1.321 1.285 1 9
0.07217
1.315
1 1/2
1.500 12 1.446 1.410 1 3
0.07217
1.581
Standards set by American Society of Mechanical Engineers

Contact Eagle Fastener

Eagle Fastener Corporation
453 E. Dartmoor Drive
Crystal Lake, IL 60014
Mailing Address: PO Box 1259
Crystal Lake, IL 60039-1259
800 . 323 . 6142 ( t )
815 . 455 . 7177 ( t )
815 . 455 . 7205 ( f )
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