Thread data sheet

Basic Thread Dimensions

Property Inch mm
Nominal Diameter 1.125 28.575
Pitch (TPI)7
Pitch (Distance) 0.1429 3.63
Pitch Diameter 1.0322 26.218
Minor Diameter 0.9549 24.254
Thread Height 0.0773 1.963
Addendum 0.0464 1.179
Crest (External)
Root (Internal)
0.0179 0.455
Tap Drill Size
(75% depth)
0.986 25.04
Lead Angle
(Single Start)
2.52°
Thread Family Unified Coarse Pitch (UNC)
Relevant Standards ASME B1.1-2003
Equivalent MetricThreadM30

For more threading data scroll down, or use the Thread Calculator

Choose the Threading Data you want to explore


1 1/8 - 7 UNCPossible Thread Classes

External Threads

1A, 2A, 3A

Metric ISO External Thread - Tolerance sketch

Internal Threads

1B, 2B, 3B

Metric ISO Internal Thread - Tolerance sketch

1 1/8 - 7 UNC 1A (External)

* Permisable values for thread Class 1A

# Description Value (Inch) Value (mm)
es Allowance 0.0021 (Ref) 0.053 (Ref)
d Major Diameter 1.0983 - 1.1229 27.897 - 28.522
d2 Pitch Diameter 1.0197 - 1.0301 25.9 - 26.165
d3 Minor Diameter
(UNR Only)
0.9528 (Ref) 24.201 (Ref)
α Varation of 30° anngle (+/-) 0.75°
P Varation of pitch (+/-) 0.003 (Ref) 0.076 (Ref)

* Values are calculated for Length of engagement of 5xPitch. For calculations of different engagement length use the Thread Calculator'

* Back to Thread Class Selection


1 1/8 - 7 UNC 2A (External)

* Permisable values for thread Class 2A

# Description Value (Inch) Value (mm)
es Allowance 0.0021 (Ref) 0.053 (Ref)
d Major Diameter 1.1065 - 1.1229 28.105 - 28.522
d2 Pitch Diameter 1.0232 - 1.0301 25.989 - 26.165
d3 Minor Diameter
(UNR Only)
0.9528 (Ref) 24.201 (Ref)
α Varation of 30° anngle (+/-) 0.75°
P Varation of pitch (+/-) 0.002 (Ref) 0.051 (Ref)

* Values are calculated for Length of engagement of 5xPitch. For calculations of different engagement length use the Thread Calculator'

* Back to Thread Class Selection


1 1/8 - 7 UNC 3A (External)

* Permisable values for thread Class 3A

# Description Value (Inch) Value (mm)
es Allowance 0 (Ref) 0 (Ref)
d Major Diameter 1.1086 - 1.125 28.158 - 28.575
d2 Pitch Diameter 1.027 - 1.0322 26.086 - 26.218
d3 Minor Diameter
(UNR Only)
0.9549 (Ref) 24.254 (Ref)
α Varation of 30° anngle (+/-) 0.75°
P Varation of pitch (+/-) 0.0015 (Ref) 0.038 (Ref)

* Values are calculated for Length of engagement of 5xPitch. For calculations of different engagement length use the Thread Calculator'

* Back to Thread Class Selection


1 1/8 - 7 UNC 1B (Internal)

* Permisable values for thread Class 1B

# Description Value (Inch) VValue (mm)
D1 Minor Diameter 0.97 - 0.998 24.638 - 25.349
D2 Pitch Diameter 1.0322 - 1.0457 26.218 - 26.561
D Major Diameter 1.1250 (Min) 28.575 (Min)
α Varation of 30° anngle (+/-) 0.75°
P Varation of Pitch (+/-) 0.0039 (Ref) 0.099 (Ref)

* Values are calculated for Length of engagement of 5xPitch. For calculations of different engagement length use the Thread Calculator

* Back to Thread Class Selection


1 1/8 - 7 UNC 2B (Internal)

* Permisable values for thread Class 2B

# Description Value (Inch) VValue (mm)
D1 Minor Diameter 0.97 - 0.998 24.638 - 25.349
D2 Pitch Diameter 1.0322 - 1.0412 26.218 - 26.446
D Major Diameter 1.1250 (Min) 28.575 (Min)
α Varation of 30° anngle (+/-) 0.75°
P Varation of Pitch (+/-) 0.0026 (Ref) 0.066 (Ref)

* Values are calculated for Length of engagement of 5xPitch. For calculations of different engagement length use the Thread Calculator

* Back to Thread Class Selection


1 1/8 - 7 UNC 3B (Internal)

* Permisable values for thread Class 3B

# Description Value (Inch) VValue (mm)
D1 Minor Diameter 0.9704 - 0.9875 24.648 - 25.083
D2 Pitch Diameter 1.0322 - 1.039 26.218 - 26.391
D Major Diameter 1.1250 (Min) 28.575 (Min)
α Varation of 30° anngle (+/-) 0.75°
P Varation of Pitch (+/-) 0.0019 (Ref) 0.048 (Ref)

* Values are calculated for Length of engagement of 5xPitch. For calculations of different engagement length use the Thread Calculator

* Back to Thread Class Selection


Over Wire Measurements for 1 1/8 - 7 UNC


* OverWire is a measuring method to obatin the pitch diameter of threads. It is mostly used when a manufacturer does not have a Go/Nogo gauge for a thread. You can learn more about it here

Inch mm
Permissible Wire Diameter Range 0.0722 - 0.1444 1.834 - 3.667
Ideal Wire Diameter 0.0825 2.096
Possible Wires
From Standard Sets
* 0.077
* 0.0825
* 0.0962
* 0.105
* 0.1155
* 0.1283
* 0.1443
* 2.021
* 2.309
* 2.598
* 2.887
* 3.175
* 3.464

Once you know your wire diameter, you need to find out what is the premissable Measurement for your pitch diameter (Depending on the class). Use our Over Wire Calculator to find out!


CNC Gcode Program for Turning of 1 1/8 - 7 UNC

The below sample Gcode is configured for:

  • Fanuc Controller
  • External RH Thread
  • Right hand tool, machining towards the chuck
  • Flank Infeed method with contant volume
  • Flank Infeed method with contant volume
  • Cutting conditions for steel
  • Default number of passes

You can configure all the above parameters and much more in our Thread Turning Gcode Generator


%
O0100
(MACHINING DOCTOR - THREADING CNC PROGRAM)
(CONTROLER - FANUC A)
(THREAD - D=1.125 INCH, P=0.14285714285714 INCH, L=1.4285714285714 INCH)
(APPLICATION - EXTERNAL TURNING, TOWARDS CHUCK, RH TOOL, RH THREAD)
(FEED - 17 PASSES, FLANK, CONSTANT VOLUME)
(FINISH PASS - 0.0013 INCH)
(WITH CHAMFER -  NO)
G28 U0 W0
T0101 G99 G97 S1019 M03
G00 Z10.2
X 38.7 M08
G76 P010060 Q33 R0.033
G76 X24.123 Z-36.286 P2226 Q532 F3.629 R0.00 
G28 U0 W0
M09
M30
%

CNC Gcode Program for Thread Milling of 1 1/8 - 7 UNC

The below sample Gcode is configured for:

  • Fanuc Controller
  • Internal RH Thread
  • Climb Milling
  • Cutter diameter: 70% of the thread diameter
  • Single tooth Thread Mill cutter
  • Cutting conditions for steel
  • One radial pass

You can configure all the above parameters and much more in our Thread Milling Gcode Generator


%
O101
(WWW.MACHININGDOCTOR.COM - THREADMILLING PROGRAM)
(CONTROLER - FANUC)
(THREAD - D=1.125 INCH, P=0.14285714285714 INCH, L=1.4285714285714 INCH)
(APPLICATION - INTERNAL, RH THREAD, CLIMB MILLING)
(CUTTER - D=0.5625 [SINGLE TOOTH])
N1 M06 T1
G54
G90 G40 G17 G94 G21
G00 X0 Y0 S2037 M03
G43 H1 Z25.4 M08
(M-CODE "THROUGH COOLANT ON")
(PASS 1 / 1)
G90 G01 Z-36.7393 F2032
G91 G01 G41 D1 X3.5719 Y-3.5719 F310
G03 X3.5719 Y3.5719 Z0.4536 I0 J3.5719 F78
G03 Z3.6286 I-7.1438 J0 F155
G03 Z3.6286 I-7.1438 J0
G03 Z3.6286 I-7.1438 J0
G03 Z3.6286 I-7.1438 J0
G03 Z3.6286 I-7.1438 J0
G03 Z3.6286 I-7.1438 J0
G03 Z3.6286 I-7.1438 J0
G03 Z3.6286 I-7.1438 J0
G03 Z3.6286 I-7.1438 J0
G03 Z3.6286 I-7.1438 J0
G03 X-3.5719 Y3.5719 Z0.4536 I-3.5719 J0
G01 G40 X-3.5719 Y-3.5719 F2032
G90 G00 Z25.4
M30
(PLEASE NOTE THIS GCODE HAS NOT BEEN TESTED ON YOUR MACHINE AND SETUP. WE CANNOT GUARANTEE ITS ACCURACY OR COMPATIBILITY. NOTE THAT YOU ARE USING IT AT YOUR OWN RISK, AND WE SHALL NOT BE HELD LIABLE FOR ANY DAMAGES OR LOSSES ARISING FROM THE USE OF THIS PROGRAM.)
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