STUB ACME THREAD DIMENSIONS CHART


Stub ACME thread dimensions chart according to ASME/ANSI B1.8-1988 standard.

Stub Acme Thread

STUB ACME FORM OF THREAD


NOMINAL DIAMETER 1/4 TO 7/16
Nominal Diameter D 1/4 5/16 3/8 7/16
Thread/in. 16 14 12 12
External Threads
Max Major Dia. 0.2500 0.3125 0.3750 0.4375
Min. Major Dia. 0.2469 0.3089 0.3708 0.4333
Max. Pitch Dia. 0.2272 0.2871 0.3451 0.4076
Min Pitch Dia. 0.2167 0.2757 0.3328 0.3950
Max. Minor Dia. 0.2024 0.2597 0.3150 0.3775
Min. Minor Dia. 0.1919 0.2483 0.3027 0.3649
Internal Threads
Max Major Dia. 0.2600 0.3225 0.3850 0.4475
Min. Major Dia. 0.2705 0.3339 0.3973 0.4601
Max. Pitch Dia. 0.2312 0.2911 0.3500 0.4125
Min Pitch Dia. 0.2417 0.3025 0.3623 0.4251
Max. Minor Dia. 0.2125 0.2696 0.3250 0.3875
Min. Minor Dia. 0.2156 0.2732 0.3292 0.3917
NOMINAL DIAMETER 1/2 TO 7/8
Nominal Diameter D 1/2 5/8 3/4 7/8
Thread/in. 10 8 6 6
External Threads
Max Major Dia. 0.5000 0.6250 0.7500 0.8750
Min. Major Dia. 0.4950 0.6188 0.7417 0.8667
Max. Pitch Dia. 0.4643 0.5812 0.6931 0.8175
Min Pitch Dia. 0.4506 0.5658 0.6757 0.7996
Max. Minor Dia. 0.4200 0.5300 0.6300 0.7550
Min. Minor Dia. 0.4063 0.5146 0.6126 0.7371
Internal Threads
Max Major Dia. 0.5200 0.6450 0.7700 0.8950
Min. Major Dia. 0.5337 0.6604 0.7874 0.9129
Max. Pitch Dia. 0.4700 0.5875 0.7000 0.8250
Min Pitch Dia. 0.4837 0.6029 0.7174 0.8429
Max. Minor Dia. 0.4400 0.5500 0.6500 0.7750
Min. Minor Dia. 0.4450 0.5562 0.6583 0.7833
NOMINAL DIAMETER 1 TO 1 3/8
Nominal Diameter D 1 1 1/8 1 1/4 1 3/8
Thread/in. 5 5 5 4
External Threads
Max Major Dia. 1.0000 1.1250 1.2500 1.3750
Min. Major Dia. 0.9900 1.1150 1.2400 1.3625
Max. Pitch Dia. 0.9320 1.0565 1.1811 1.2906
Min Pitch Dia. 0.9126 1.0367 1.1610 1.2686
Max. Minor Dia. 0.8600 0.9850 1.1100 1.2050
Min. Minor Dia. 0.8406 0.9652 1.0899 1.1830
Internal Threads
Max Major Dia. 1.0200 1.1450 1.2700 1.3950
Min. Major Dia. 1.0394 1.1648 1.2901 1.4170
Max. Pitch Dia. 0.9400 1.0650 1.1900 1.3000
Min Pitch Dia. 0.9594 1.0848 1.2101 1.3220
Max. Minor Dia. 0.8800 1.0050 1.1300 1.2250
Min. Minor Dia. 0.8900 1.0150 1.1400 1.2375
NOMINAL DIAMETER 1 1/2 TO 2 1/4
Nominal Diameter D 1 1/2 1 3/4 2 2 1/4
Thread/in. 4 4 4 3
External Threads
Max Major Dia. 1.5000 1.7500 2.0000 2.2500
Min. Major Dia. 1.4875 1.7375 1.9875 2.2333
Max. Pitch Dia. 1.4152 1.6645 1.9137 2.1380
Min Pitch Dia. 1.3929 1.6416 1.8902 2.1117
Max. Minor Dia. 1.3300 1.5800 1.8300 2.0300
Min. Minor Dia. 1.3077 1.5571 1.8065 2.0037
Internal Threads
Max Major Dia. 1.5200 1.7700 2.0200 2.2700
Min. Major Dia. 1.5423 1.7929 2.0435 2.2963
Max. Pitch Dia. 1.4250 1.6750 1.9250 2.1500
Min Pitch Dia. 1.4473 1.6979 1.9485 2.1763
Max. Minor Dia. 1.3500 1.6000 1.8500 2.0500
Min. Minor Dia. 1.3625 1.6125 1.8625 2.0667
NOMINAL DIAMETER 2 1/2 TO 3 1/2
Nominal Diameter D 2 1/2 2 3/4 3 3 1/2
Thread/in. 3 3 2 2
External Threads
Max Major Dia. 2.5000 2.7500 3.0000 3.5000
Min. Major Dia. 2.4833 2.7333 2.9750 3.4750
Max. Pitch Dia. 2.3874 2.6367 2.8360 3.3350
Min Pitch Dia. 2.3606 2.6094 2.8044 3.3026
Max. Minor Dia. 2.2800 2.5300 2.6800 3.1800
Min. Minor Dia. 2.2532 2.5027 2.6484 3.1476
Internal Threads
Max Major Dia. 2.5200 2.7700 3.0200 3.5200
Min. Major Dia. 2.5468 2.7973 3.0516 3.5524
Max. Pitch Dia. 2.4000 2.6500 2.8500 3.3500
Min Pitch Dia. 2.4268 2.6773 2.8816 3.3824
Max. Minor Dia. 2.3000 2.5500 2.7000 3.2000
Min. Minor Dia. 2.3167 2.5667 2.7250 3.2250
NOMINAL DIAMETER 2 1/2 TO 3 1/2
Nominal Diameter D 4 4 1/2 5
Thread/in. 2 2 2
External Threads
Max Major Dia. 4.0000 4.5000 5.0000
Min. Major Dia. 3.9750 4.4750 4.9750
Max. Pitch Dia. 3.8340 4.3330 4.8319
Min Pitch Dia. 3.8008 4.2991 4.7973
Max. Minor Dia. 3.6800 4.1800 4.6800
Min. Minor Dia. 3.6468 4.1461 4.6454
Internal Threads
Max Major Dia. 4.0200 4.5200 5.0200
Min. Major Dia. 4.0532 4.5539 5.0546
Max. Pitch Dia. 3.8500 4.3500 4.8500
Min Pitch Dia. 3.8832 4.3839 4.8846
Max. Minor Dia. 3.7000 4.2000 4.7000
Min. Minor Dia. 3.7250 4.2250 4.7250

Definitions:

Major Diameter: The maximum diameter of a thread which is diameter of the crest of a male thread or root of a female thread.

Minor Diameter: The minimum diameter of a thread which is diameter of the root of a male thread or crest of a female thread.

Threads per inch: Number of full thread per an inch length.


Supplements:

Link Usage
Stub Acme Thread Dimensions Calculator Calculator form of the Stub Acme thread dimensions chart.

Reference:

  • Oberg, E. , Jones ,F.D. , Horton H.L. , Ryffel H.H., (2016) . Machinery's Handbook . 30th edition.  Industrial Press Inc.
  • Oberg, E. , Jones ,F.D. , Horton H.L. , Ryffel H.H., (2012) . Machinery's Handbook . 29th edition.  Industrial Press Inc.
  • ASME B1.8-1998, Stub Acme Screw Threads