External ACME Thread General Purpose Size Table Chart

ANSI Hardware Engineering Data
Internal ACME Thread General Purpose Size Chart

 

The following table defines recommended industry standard sizes for External ACME General Purpose Threads per American National Standard ASME/ANSI B1.5.

There are three classes of General Purpose ACME threads, 2G, 3G, and 4G each class provides some clearance on all standard size diameters for free movement, and are used in assemblies with the internal thread rigidly fixed and movement of the external thread in a direction perpendicular to its axis limited by its bearing or bearings.

Designs should only utilize external and internal ACME threads of the same class and type, with Class 2G being the preferred choice. If less backlash or end play is desired, Classes 3G and 4G are provided. Class 5G is not recommended for new designs.

ACME General Purpose Thread‚Äč

General Pupose ACME External Thread Table Chart

Designation
Size
Decimal
TPI
Tol.
Class
Major Dia.
Pitch Dia.
Minor Dia.
Max.
Min.
Max.
Min.
Max
Min.
1/4-16 Acme
0.25
16
2G
0.2500
0.2450
0.2148
0.2043
0.1775
0.1618
1/4-16 Acme
0.25
16
3G
0.2500
0.2450
0.2158
0.2109
0.1775
0.1702
1/4-16 Acme
0.25
16
4G
0.2500
0.2450
0.2168
0.2133
0.1775
0.1722
1/4-16 Acme
0.25
16
5G
0.2500
0.2450
0.2188
0.2160
0.1775
0.1733
5/16-14 Acme
0.3125
14
2G
0.3125
0.3075
0.2728
0.2614
0.2311
0.2140
5/16-14 Acme
0.3125
14
3G
0.3125
0.3075
0.2738
0.2685
0.2311
0.2231
5/16-14 Acme
0.3125
14
4G
0.3125
0.3075
0.2748
0.271
0.2311
0.2254
5/16-14 Acme
0.3125
14
5G
0.3125
0.3075
0.2768
0.2738
0.2311
0.2266
3/8-12 Acme
0.375
12
2G
0.3750
0.3700
0.3284
0.3161
0.2817
0.2632
3/8-12 Acme
0.375
12
3G
0.3750
0.3700
0.3296
0.3238
0.2817
0.2730
3/8-12 Acme
0.375
12
4G
0.3750
0.3700
0.3309
0.3268
0.2817
0.2755
3/8-12 Acme
0.375
12
5G
0.3750
0.3700
0.3333
0.33
0.2817
0.2767
7/16-12 Acme
0.4375
12
2G
0.4375
0.4325
0.3909
0.3783
0.3442
0.3253
7/16-12 Acme
0.4375
12
3G
0.4375
0.4325
0.3921
0.3862
0.3442
0.3354
7/16-12 Acme
0.4375
12
4G
0.4375
0.4325
0.3934
0.3892
0.3442
0.3379
7/16-12 Acme
0.4375
12
5G
0.4375
0.4325
0.3958
0.3924
0.3442
0.3391
1/2-10 Acme
0.5
10
2G
0.5000
0.4950
0.4443
0.4306
0.3800
0.3594
1/2-10 Acme
0.5
10
3G
0.5000
0.4950
0.4458
0.4394
0.3800
0.3704
1/2-10 Acme
0.5
10
4G
0.5000
0.4950
0.4472
0.4426
0.3800
0.3731
1/2-10 Acme
0.5
10
5G
0.5000
0.4950
0.45
0.4463
0.3800
0.3745
5/8-8 Acme
0.625
8
2G
0.6250
0.6188
0.5562
0.5408
0.4800
0.4569
5/8-8 Acme
0.625
8
3G
0.6250
0.6188
0.5578
0.5506
0.4800
0.4692
5/8-8 Acme
0.625
8
4G
0.6250
0.6188
0.5593
0.5542
0.4800
0.4723
5/8-8 Acme
0.625
8
5G
0.6250
0.6188
0.5625
0.5584
0.4800
0.4738
3/4-6 Acme
0.75
6
2G
0.7500
0.7417
0.6598
0.6424
0.5633
0.5372
3/4-6 Acme
0.75
6
3G
0.7500
0.7417
0.6615
0.6534
0.5633
0.5511
3/4-6 Acme
0.75
6
4G
0.7500
0.7417
0.6632
0.6574
0.5633
0.5546
3/4-6 Acme
0.75
6
5G
0.7500
0.7417
0.6667
0.662
0.5633
0.5563
7/8-6 Acme
0.875
6
2G
0.8750
0.8667
0.7842
0.7663
0.6883
0.6615
7/8-6 Acme
0.875
6
3G
0.8750
0.8667
0.7861
0.7778
0.6883
0.6758
7/8-6 Acme
0.875
6
4G
0.8750
0.8667
0.788
0.782
0.6883
0.6794
7/8-6 Acme
0.875
6
5G
0.8750
0.8667
0.7917
0.7869
0.6883
0.6811
1-5 Acme
1
5
2G
1.0000
0.9900
0.892
0.8726
0.7800
0.7509
1-5 Acme
1
5
3G
1.0000
0.9900
0.894
0.8849
0.7800
0.7664
1-5 Acme
1
5
4G
1.0000
0.9900
0.896
0.8895
0.7800
0.7703
1-5 Acme
1
5
5G
1.0000
0.9900
0.9
0.8948
0.7800
0.7722
1 1/8-5 Acme
1.125
5
2G
1.1250
1.1150
1.0165
0.9967
0.9050
0.8753
1 1/8-5 Acme
1.125
5
3G
1.1250
1.1150
1.0186
1.0094
0.9050
0.8912
1 1/8-5 Acme
1.125
5
4G
1.1250
1.1150
1.0208
1.0142
0.9050
0.8951
1 1/8-5 Acme
1.125
5
5G
1.1250
1.1150
1.025
1.0197
0.9050
0.8971
1 1/4-5 Acme
1.25
5
2G
1.2500
1.2400
1.1411
1.121
1.0300
0.9998
1 1/4-5 Acme
1.25
5
3G
1.2500
1.2400
1.1433
1.1339
1.0300
1.0159
1 1/4-5 Acme
1.25
5
4G
1.2500
1.2400
1.1455
1.1388
1.0300
1.0199
1 1/4-5 Acme
1.25
4
5G
1.2500
1.2400
1.15
1.1446
1.0300
1.0219
1 3/8-4 Acme
1.375
4
2G
1.3750
1.3625
1.2406
1.2188
1.1050
1.0720
1 3/8-4 Acme
1.375
4
3G
1.3750
1.3625
1.243
1.2327
1.1050
1.0896
1 3/8-4 Acme
1.375
4
4G
1.3750
1.3625
1.2453
1.238
1.1050
1.0940
1 3/8-4 Acme
1.375
4
5G
1.3750
1.3625
1.25
1.2441
1.1050
1.0962
1 1/2-4 Acme
1.5
4
2G
1.5000
1.4875
1.3652
1.3429
1.2300
1.1965
1 1/2-4 Acme
1.5
4
3G
1.5000
1.4875
1.3677
1.3573
1.2300
1.2144
1 1/2-4 Acme
1.5
4
4G
1.5000
1.4875
1.3701
1.3627
1.2300
1.2189
1 1/2-4 Acme
1.5
4
5G
1.5000
1.4875
1.375
1.369
1.2300
1.2210
1 3/4-4 Acme
1.75
4
2G
1.7500
1.7375
1.6145
1.5916
1.4800
1.4456
1 3/4-4 Acme
1.75
4
3G
1.7500
1.7375
1.6171
1.6064
1.4800
1.4640
1 3/4-4 Acme
1.75
4
4G
1.7500
1.7375
1.6198
1.6122
1.4800
1.4686
1 3/4-4 Acme
1.75
4
5G
1.7500
1.7375
1.625
1.6189
1.4800
1.4708
2-4 Acme
2
4
2G
2.0000
1.9875
1.8637
1.8402
1.7300
1.6948
2-4 Acme
2
4
3G
2.0000
1.9875
1.8665
1.8555
1.7300
1.7135
2-4 Acme
2
4
4G
2.0000
1.9875
1.8693
1.8615
1.7300
1.7183
2-4 Acme
2
4
5G
2.0000
1.9875
1.875
1.8687
1.7300
1.7206
2 1/4-3 Acme
2.25
3
2G
2.2500
2.2333
2.0713
2.045
1.8967
1.8572
2 1/4-3 Acme
2.25
3
3G
2.2500
2.2333
2.0743
2.062
1.8967
1.8783
2 1/4-3 Acme
2.25
3
4G
2.2500
2.2333
2.0773
2.0685
1.8967
1.8835
2 1/4-3 Acme
2.25
3
5G
2.2500
2.2333
2.0833
2.0763
1.8967
1.8862
2 1/2-3 Acme
2.5
3
2G
2.5000
2.4833
2.3207
2.2939
2.1467
2.1065
2 1/2-3 Acme
2.5
3
3G
2.5000
2.4833
2.3238
2.3113
2.1467
2.1279
2 1/2-3 Acme
2.5
3
4G
2.5000
2.4833
2.327
2.3181
2.1467
2.1333
2 1/2-3 Acme
2.5
3
5G
2.5000
2.4833
2.333
2.3262
2.1467
2.1360
2 3/4-3 Acme
2.75
3
2G
2.7500
2.7333
2.57
2.5427
2.3967
2.3558
2 3/4-3 Acme
2.75
3
3G
2.7500
2.7333
2.5734
2.567
2.3967
2.3776
2 3/4-3 Acme
2.75
3
4G
2.7500
2.7333
2.5767
2.5676
2.3967
2.3831
2 3/4-3 Acme
2.75
3
5G
2.7500
2.7333
2.5833
2.576
2.3967
2.3858
3-2 Acme
3
2
2G
3.0000
2.9750
2.736
2.7044
2.4800
2.4326
3-2 Acme
3
2
3G
3.0000
2.9750
2.7395
2.7248
2.4800
2.4579
3-2 Acme
3
2
4G
3.0000
2.9750
2.743
2.7325
2.4800
2.4642
3-2 Acme
3
2
5G
3.0000
2.9750
2.75
2.7416
2.4800
2.4674
3 1/2-2 Acme
3.5
2
2G
3.5000
3.4750
3.235
3.2026
2.9800
2.9314
3 1/2-2 Acme
3.5
2
3G
3.5000
3.4750
3.2388
3.2237
2.9800
2.9574
3 1/2-2 Acme
3.5
2
4G
3.5000
3.4750
3.2425
3.2317
2.9800
2.9638
3 1/2-2 Acme
3.5
2
5G
3.5000
3.4750
3.25
3.2413
2.9800
2.9669
4-2 Acme
4
2
2G
4.0000
3.9750
3.734
3.7008
3.4800
3.4302
4-2 Acme
4
2
3G
4.0000
3.9750
3.738
3.7225
3.4800
3.4568
4-2 Acme
4
2
4G
4.0000
3.9750
3.742
3.7309
3.4800
3.4634
4-2 Acme
4
2
5G
4.0000
3.9750
3.75
3.7411
3.4800
3.4666
4 1/2-2 Acme
4.5
2
2G
4.5000
4.4750
4.233
4.1991
3.9800
3.9291
4 1/2-2 Acme
4.5
2
3G
4.5000
4.4750
4.2373
4.2215
3.9800
3.9563
4 1/2-2 Acme
4.5
2
4G
4.5000
4.4750
4.2415
4.2302
3.9800
3.9631
4 1/2-2 Acme
4.5
2
5G
4.5000
4.4750
4.25
4.2409
3.9800
3.9663
5-2 Acme
5
2
2G
5.0000
4.9750
4.7319
4.6973
4.4800
4.4281
5-2 Acme
5
2
3G
5.0000
4.9750
4.7364
4.7202
4.4800
4.4557
5-2 Acme
5
2
4G
5.0000
4.9750
4.7409
4.7294
4.4800
4.4627
5-2 Acme
5
2
5G
5.0000
4.9750
4.75
4.7408
4.4800
4.4662

Related Resouces:

Contribute Article
Spider Optimizer

© Copyright 2000 - 2017, by Engineers Edge, LLC www.engineersedge.com
All rights reserved
Disclaimer | Feedback | Advertising | Contact


User Reviews/Comments:

There are currently no comments available.


Add a Comment (you must be logged in to post comment Register):
Name:
Email: (Optional)
Comment: