Coarse Thread

National Coarse Thread Sizes (UNC/UNRC)

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)
#1 0.073 64 0.063 0.056 4 31 0.01353
0.003
#2 0.086 56 0.074 0.067 4 22 0.01547
0.004
#3 0.099 48 0.086 0.076 4 26 0.01804
0.005
#4 0.112 40 0.096 0.085 4 45 0.02165
0.006
#5 0.125 40 0.109 0.098 4 11 0.02165
0.008
#6 0.138 32 0.118 0.104 4 50 0.02706
0.009
#8 0.164 32 0.144 0.130 3 58 0.02706
0.014
#10 0.190 24 0.163 0.145 4 39 0.03608
0.018
#12 0.216 24 0.189 0.171 4 1 0.03608
0.024
1/4 0.250 20 0.218 0.196 4 11 0.04330
0.032
5/16 0.313 18 0.276 0.252 3 40 0.04811
0.052
3/8 0.375 16 0.334 0.307 3 24 0.05413
0.078
7/16 0.438 14 0.391 0.360 3 20 0.06186
0.106
1/2 0.500 13 0.450 0.417 3 7 0.06662
0.142
9/16 0.563 12 0.508 0.472 2 59 0.07217
0.182
5/8 0.625 11 0.566 0.527 2 56 0.07873
0.226
3/4 0.750 10 0.685 0.642 2 40 0.08660
0.334
7/8 0.875 9 0.803 0.755 2 31 0.09623
0.462
1 1.000 8 0.919 0.865 2 29 0.10825
0.606
1 1/8 1.125 7 1.032 0.941 2 31 0.12372
0.763
1 1/4 1.250 7 1.157 1.095 2 15 0.12372
0.969
1 3/8 1.375 6 1.267 1.195 2 24 0.14434
1.155
1 1/2 1.500 6 1.392 1.320 2 11 0.14434
1.405
1 3/4 1.750 5 1.620 1.534 2 15 0.17321
1.900
2 2.000 4 1/2 1.856 1.759 2 11 0.19245
2.500
2 1/4 2.250 4 1/2 2.106 2.009 1 55 0.19245
3.250
2 1/2 2.500 4 2.338 2.229 1 57 0.21651
4.000
2 3/4 2.750 4 2.588 2.479 1 46 0.21651
4.930
3 3.000 4 2.838 2.729 1 36 0.21651
5.970
3 1/4 3.250 4 3.088 2.979 1 29 0.21651
7.100
3 1/2 3.500 4 3.338 3.229 1 22 0.21651
8.330
3 3/4 3.750 4 3.588 3.479 1 16 0.21651
9.660
4 4.000 4 3.838 3.729 1 11 0.21651
11.080
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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