Thread data sheet

Basic Thread Dimensions

Property Inch mm
Nominal Diameter 1.812 46.025
Pitch (TPI)8
Pitch (Distance) 0.125 3.175
Pitch Diameter 1.7308 43.962
Minor Diameter 1.6632 42.245
Thread Height 0.0677 1.72
Addendum 0.0406 1.031
Crest (External)
Root (Internal)
0.0156 0.396
Tap Drill Size
(75% depth)
1.69 42.93
Lead Angle
(Single Start)
1.32°
Thread Family Unified Constant Pitch 8 TPI (8-UN)
Relevant Standards ASME B1.1-2003
Equivalent MetricThreadM45 X 3

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

Choose the Threading Data you want to explore


1 13/16 - 8 8-UNPossible Thread Classes

External Threads

2A, 3A

Metric ISO External Thread - Tolerance sketch

Internal Threads

2B, 3B

Metric ISO Internal Thread - Tolerance sketch

1 13/16 - 8 8-UN 2A (External)

* Permisable values for thread Class 2A

# Description Value (Inch) Value (mm)
es Allowance 0.002 (Ref) 0.051 (Ref)
d Major Diameter 1.795 - 1.81 45.593 - 45.974
d2 Pitch Diameter 1.722 - 1.7288 43.739 - 43.912
d3 Minor Diameter
(UNR Only)
1.6611 (Ref) 42.192 (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 13/16 - 8 8-UN 3A (External)

* Permisable values for thread Class 3A

# Description Value (Inch) Value (mm)
es Allowance 0 (Ref) 0 (Ref)
d Major Diameter 1.797 - 1.812 45.644 - 46.025
d2 Pitch Diameter 1.7257 - 1.7308 43.833 - 43.962
d3 Minor Diameter
(UNR Only)
1.6632 (Ref) 42.245 (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 13/16 - 8 8-UN 2B (Internal)

* Permisable values for thread Class 2B

# Description Value (Inch) VValue (mm)
D1 Minor Diameter 1.677 - 1.702 42.596 - 43.231
D2 Pitch Diameter 1.7308 - 1.7396 43.962 - 44.186
D Major Diameter 1.8120 (Min) 46.025 (Min)
α Varation of 30° anngle (+/-) 0.75°
P Varation of Pitch (+/-) 0.0025 (Ref) 0.064 (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 13/16 - 8 8-UN 3B (Internal)

* Permisable values for thread Class 3B

# Description Value (Inch) VValue (mm)
D1 Minor Diameter 1.6767 - 1.6917 42.588 - 42.969
D2 Pitch Diameter 1.7308 - 1.7374 43.962 - 44.13
D Major Diameter 1.8120 (Min) 46.025 (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 13/16 - 8 8-UN


* 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 0.0631 - 0.1263 1.604 - 3.208
Ideal Wire Diameter 0.0722 1.833
Possible Wires
From Standard Sets
* 0.0642
* 0.0722
* 0.077
* 0.0825
* 0.0962
* 0.105
* 0.1155
* 1.732
* 2.021
* 2.309
* 2.598
* 2.887
* 3.175

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 13/16 - 8 8-UN

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=1.812 INCH, P=0.125 INCH, L=1.25 INCH)
(APPLICATION - EXTERNAL TURNING, TOWARDS CHUCK, RH TOOL, RH THREAD)
(FEED - 17 PASSES, FLANK, CONSTANT VOLUME)
(FINISH PASS - 0.0012 INCH)
(WITH CHAMFER -  NO)
G28 U0 W0
T0101 G99 G97 S632 M03
G00 Z9.5
X 56.2 M08
G76 P010060 Q30 R0.03
G76 X42.13 Z-31.75 P1948 Q465 F3.175 R0.00 
G28 U0 W0
M09
M30
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CNC Gcode Program for Thread Milling of 1 13/16 - 8 8-UN

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=1.812 INCH, P=0.125 INCH, L=1.25 INCH)
(APPLICATION - INTERNAL, RH THREAD, CLIMB MILLING)
(CUTTER - D=0.906 [SINGLE TOOTH])
N1 M06 T1
G54
G90 G40 G17 G94 G21
G00 X0 Y0 S1265 M03
G43 H1 Z25.4 M08
(M-CODE "THROUGH COOLANT ON")
(PASS 1 / 1)
G90 G01 Z-32.1469 F2032
G91 G01 G41 D1 X5.7531 Y-5.7531 F193
G03 X5.7531 Y5.7531 Z0.3969 I0 J5.7531 F48
G03 Z3.175 I-11.5062 J0 F96
G03 Z3.175 I-11.5062 J0
G03 Z3.175 I-11.5062 J0
G03 Z3.175 I-11.5062 J0
G03 Z3.175 I-11.5062 J0
G03 Z3.175 I-11.5062 J0
G03 Z3.175 I-11.5062 J0
G03 Z3.175 I-11.5062 J0
G03 Z3.175 I-11.5062 J0
G03 Z3.175 I-11.5062 J0
G03 X-5.7531 Y5.7531 Z0.3969 I-5.7531 J0
G01 G40 X-5.7531 Y-5.7531 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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