Date Published:Jun. 18. 2015

Unified Coarse Screw Threads/Unified Fine Screw Threads

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Unified Coarse Screw Threads/Unified Fine Screw Threads

Basic profile, formula and basic dimensions of unified coarse threads / fine threads

Unified coarse threads

Unit : mm
Nominal diameter of thread Female Screw 
Root
diameter D 
Effective
diameter D2 
Inside
diameter D1 
Male Screw 
Outside
diameter d 
Effective
diameter d2
Root
diameter d1 

No. 2-56 UNC

No. 1 - 64 UNC

No. 3 - 48 UNC 
  1.854
  2.184
  2.515
  1.598
  1.890
  2.172
  1.425
  1.694
  1.941
No. 4-40 UNC
No. 5-40 UNC
No. 6-32 UNC 
    2.845
  3.175
  3.505
  2.433
  2.764
  2.990
  2.156
  2.487
  2.647
No.   8-32 UNC
No. 10-24 UNC

 


No.12 - 24 UNC 
  4.166
  4.826
  5.486
  3.650
  4.138
  4.798
  3.307
  3.680
  4.341
1/4   -20 UNC
5/16 -18 UNC
3/8   -16 UNC
    6.350
  7.938
  9.525
  5.524
  7.021
  8.494
  4.976
  6.411
  7.805
7/16 -14 UNC
1/2   -13 UNC 
  11.112
12.700
  9.934
11.430
  9.149
10.584

Prioritize Field 1, and choose Field 2 as needed.

Unified fine threads

Unit : mm
No. 0-80 UNF

No. 2-64 UNF 

No. 1 - 72 UN
  1.524
  1.854
  2.184 
  1.318
  1.626
  1.928
  1.181
  1.473
  1.755

No. 4-48 UNF
No. 5-44 UNF 
No. 3 - 56 UNF

 
  2.515
  2.845
  3.175
  2.220
  2.502
  2.799
  2.024
  2.271
  2.550
No.   6-40 UNF
No.   8-36 UNF
No. 10-32 UNF 
    3.505
  4.166
  4.826
  3.094
  3.708
  4.310
  2.817
  3.401
  3.967

1/4   -28 UNF
5/16 -24 UNF
No.12 - 28 UNF

 
  5.486
  6.350
  7.938
  4.897
  5.761
  7.249
  4.503
  5.367
  6.792
3/8   -24 UNF
7/16 -20 UNF
1/2   -20 UNF
    9.525
11.112
12.700
  8.837
10.287
11.874
  8.379
  9.738
11.326

Prioritize Field 1, and choose Field 2 as needed.



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