Thread data sheet

Basic Thread Dimensions

Property mm Inch
Nominal Diameter 3.5 0.1378
Pitch (Distance) 0.6 0.0236
Pitch Diameter 3.11 0.1224
Minor Diameter 2.85 0.1122
Thread Height 0.325 0.0128
Addendum 0.195 0.0077
Crest (External)
Root (Internal)		 0.075 0.003
Tap Drill Size
(75% depth)		 2.92 0.115
Lead Angle
(Single Start)		 3.51°
Thread Family Metric Coarse Pitch (MC)
Relevant Standards ISO 68-1, ISO 9651-1, ISO 965-2, ISO 261,DIN 13
Equivalent InchThread#6 - 40 UNF

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

Choose the Threading Data you want to explore

Unified Inch Thread Classes

Tolerance Classes

Thread Milling CNC program

Thread Milling Gcode

Turning Gcode

Over Wire

Tap Drill Size

Unified Inch Thread Classes

Tolerance Classes

Thread Milling Gcode

Turning Gcode

Over Wire

Tap Drill Size

M3.5Possible Thread Classes

External Threads

4g, 4h, 6e, 6g, 6h, 5g4g, 5h4h, 5g6g, 7g6g, 7h6h, 7e6e

Metric ISO External Thread - Tolerance sketch

Internal Threads

4H, 5H, 5G, 6H, 6G, 7H, 7G

Metric ISO Internal Thread - Tolerance sketch

M3.5 4g (External)

* Permisable values for thread Class 4g

# Description Value (mm) Value (Inch)
es Allowance 0.021 (Ref) 0.0008 (Ref)
d Major Diameter 3.399 - 3.479 0.1338 - 0.137
d2 Pitch Diameter 3.036 - 3.089 0.1195 - 0.1216
R Root Radius 0.075 (Min) 0.003 (Min)
C Root Truncation 0.075 - 0.149 0.003 - 0.0059
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 4h (External)

* Permisable values for thread Class 4h

# Description Value (mm) Value (Inch)
es Allowance 0 (Ref) 0 (Ref)
d Major Diameter 3.42 - 3.5 0.1346 - 0.1378
d2 Pitch Diameter 3.057 - 3.11 0.1204 - 0.1224
R Root Radius 0.075 (Min) 0.003 (Min)
C Root Truncation 0.075 - 0.149 0.003 - 0.0059
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 6e (External)

* Permisable values for thread Class 6e

# Description Value (mm) Value (Inch)
es Allowance 0.053 (Ref) 0.0021 (Ref)
d Major Diameter 3.322 - 3.447 0.1308 - 0.1357
d2 Pitch Diameter 2.972 - 3.057 0.117 - 0.1204
R Root Radius 0.075 (Min) 0.003 (Min)
C Root Truncation 0.075 - 0.17 0.003 - 0.0067
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 6g (External)

* Permisable values for thread Class 6g

# Description Value (mm) Value (Inch)
es Allowance 0.021 (Ref) 0.0008 (Ref)
d Major Diameter 3.354 - 3.479 0.132 - 0.137
d2 Pitch Diameter 3.004 - 3.089 0.1183 - 0.1216
R Root Radius 0.075 (Min) 0.003 (Min)
C Root Truncation 0.075 - 0.17 0.003 - 0.0067
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 6h (External)

* Permisable values for thread Class 6h

# Description Value (mm) Value (Inch)
es Allowance 0 (Ref) 0 (Ref)
d Major Diameter 3.375 - 3.5 0.1329 - 0.1378
d2 Pitch Diameter 3.025 - 3.11 0.1191 - 0.1224
R Root Radius 0.075 (Min) 0.003 (Min)
C Root Truncation 0.075 - 0.17 0.003 - 0.0067
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 5g4g (External)

* Permisable values for thread Class 5g4g

# Description Value (mm) Value (Inch)
es Allowance 0.021 (Ref) 0.0008 (Ref)
d Major Diameter 3.399 - 3.479 0.1338 - 0.137
d2 Pitch Diameter 3.022 - 3.089 0.119 - 0.1216
R Root Radius 0.075 (Min) 0.003 (Min)
C Root Truncation 0.075 - 0.158 0.003 - 0.0062
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 5h4h (External)

* Permisable values for thread Class 5h4h

# Description Value (mm) Value (Inch)
es Allowance 0 (Ref) 0 (Ref)
d Major Diameter 3.42 - 3.5 0.1346 - 0.1378
d2 Pitch Diameter 3.043 - 3.11 0.1198 - 0.1224
R Root Radius 0.075 (Min) 0.003 (Min)
C Root Truncation 0.075 - 0.158 0.003 - 0.0062
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 5g6g (External)

* Permisable values for thread Class 5g6g

# Description Value (mm) Value (Inch)
es Allowance 0.021 (Ref) 0.0008 (Ref)
d Major Diameter 3.354 - 3.479 0.132 - 0.137
d2 Pitch Diameter 3.022 - 3.089 0.119 - 0.1216
R Root Radius 0.075 (Min) 0.003 (Min)
C Root Truncation 0.075 - 0.158 0.003 - 0.0062
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 7g6g (External)

* Permisable values for thread Class 7g6g

# Description Value (mm) Value (Inch)
es Allowance 0.021 (Ref) 0.0008 (Ref)
d Major Diameter 3.354 - 3.479 0.132 - 0.137
d2 Pitch Diameter 2.983 - 3.089 0.1174 - 0.1216
R Root Radius 0.075 (Min) 0.003 (Min)
C Root Truncation 0.075 - 0.182 0.003 - 0.0072
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 7h6h (External)

* Permisable values for thread Class 7h6h

# Description Value (mm) Value (Inch)
es Allowance 0 (Ref) 0 (Ref)
d Major Diameter 3.375 - 3.5 0.1329 - 0.1378
d2 Pitch Diameter 3.004 - 3.11 0.1183 - 0.1224
R Root Radius 0.075 (Min) 0.003 (Min)
C Root Truncation 0.075 - 0.182 0.003 - 0.0072
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 7e6e (External)

* Permisable values for thread Class 7e6e

# Description Value (mm) Value (Inch)
es Allowance 0.053 (Ref) 0.0021 (Ref)
d Major Diameter 3.322 - 3.447 0.1308 - 0.1357
d2 Pitch Diameter 2.951 - 3.057 0.1162 - 0.1204
R Root Radius 0.075 (Min) 0.003 (Min)
C Root Truncation 0.075 - 0.182 0.003 - 0.0072
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 4H (Internal)

* Permisable values for thread Class 4H

# Description Value (mm) VValue (Inch)
EL Allowance 0 (Ref) 0 (Ref)
D1 Minor Diameter 2.85 - 2.95 0.1122 - 0.1161
D2 Pitch Diameter 3.11 - 3.181 0.1224 - 0.1252
D Major Diameter 3.5 (Min) 0.1378 (Min)
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 5H (Internal)

* Permisable values for thread Class 5H

# Description Value (mm) VValue (Inch)
EL Allowance 0 (Ref) 0 (Ref)
D1 Minor Diameter 2.85 - 2.975 0.1122 - 0.1171
D2 Pitch Diameter 3.11 - 3.2 0.1224 - 0.126
D Major Diameter 3.5 (Min) 0.1378 (Min)
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 5G (Internal)

* Permisable values for thread Class 5G

# Description Value (mm) VValue (Inch)
EL Allowance 0.021 (Ref) 0.0008 (Ref)
D1 Minor Diameter 2.871 - 2.996 0.113 - 0.118
D2 Pitch Diameter 3.131 - 3.221 0.1233 - 0.1268
D Major Diameter 3.5 (Min) 0.1378 (Min)
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 6H (Internal)

* Permisable values for thread Class 6H

# Description Value (mm) VValue (Inch)
EL Allowance 0 (Ref) 0 (Ref)
D1 Minor Diameter 2.85 - 3.01 0.1122 - 0.1185
D2 Pitch Diameter 3.11 - 3.222 0.1224 - 0.1269
D Major Diameter 3.5 (Min) 0.1378 (Min)
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 6G (Internal)

* Permisable values for thread Class 6G

# Description Value (mm) VValue (Inch)
EL Allowance 0.021 (Ref) 0.0008 (Ref)
D1 Minor Diameter 2.871 - 3.031 0.113 - 0.1193
D2 Pitch Diameter 3.131 - 3.243 0.1233 - 0.1277
D Major Diameter 3.5 (Min) 0.1378 (Min)
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 7H (Internal)

* Permisable values for thread Class 7H

# Description Value (mm) VValue (Inch)
EL Allowance 0 (Ref) 0 (Ref)
D1 Minor Diameter 2.85 - 3.05 0.1122 - 0.1201
D2 Pitch Diameter 3.11 - 3.25 0.1224 - 0.128
D Major Diameter 3.5 (Min) 0.1378 (Min)
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

M3.5 7G (Internal)

* Permisable values for thread Class 7G

# Description Value (mm) VValue (Inch)
EL Allowance 0.021 (Ref) 0.0008 (Ref)
D1 Minor Diameter 2.871 - 3.071 0.113 - 0.1209
D2 Pitch Diameter 3.131 - 3.271 0.1233 - 0.1288
D Major Diameter 3.5 (Min) 0.1378 (Min)
LE Normal Length of Engagement 1.7 - 5 0.0669 - 0.1969

* Back to Thread Class Selection

Tap Drill Sizes for M3.5

  • If not specified, assume a thread depth of 75%.
  • You can learn more about thread depth in tapping here.
  • To get the tap drill size in other depths, use our Tap Drill Size Calculator .
Thread Depth Tap Drill Size (Inch) Tap Drill Size (mm)
55% 0.121 3.07
60% 0.119 3.03
65% 0.118 2.99
70% 0.116 2.95
75% 0.115 2.92
80% 0.113 2.88
85% 0.112 2.84

Over Wire Measurements for M3.5


* 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

mm Inch
Permissible Wire Diameter Range 0.303 - 0.606 0.0119 - 0.0239
Ideal Wire Diameter 0.346 0.0136
Possible Wires
From Standard Sets		 * 0.346
* 0.404
* 0.433
* 0.462
* 0.52
* 0.577
 * 0.012
* 0.0131
* 0.0144
* 0.016
* 0.018
* 0.0193
* 0.0206
* 0.0214
* 0.0222

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 M3.5

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=3.5 MM, P=0.6 MM, L=6 MM)
(APPLICATION - EXTERNAL TURNING, TOWARDS CHUCK, RH TOOL, RH THREAD)
(FEED - 5 PASSES, FLANK, CONSTANT VOLUME)
(FINISH PASS - 0.02 MM)
(WITH CHAMFER -  NO)
G28 U0 W0
T0101 G99 G97 S5000 M03
G00 Z5.0
X 5.5 M08
G76 P010060 Q20 R0.02
G76 X2.764 Z-6.0 P368 Q156 F0.6 R0.00 
G28 U0 W0
M09
M30
%

CNC Gcode Program for Thread Milling of M3.5

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=3.5 MM, P=0.6 MM, L=6 MM)
(APPLICATION - INTERNAL, RH THREAD, CLIMB MILLING)
(CUTTER - D=1.75 [SINGLE TOOTH])
N1 M06 T1
G54
G90 G40 G17 G94 G21
G00 X0 Y0 S10000 M03
G43 H1 Z20.0 M08
(M-CODE "THROUGH COOLANT ON")
(PASS 1 / 1)
G90 G01 Z-6.075 F2000
G91 G01 G41 D1 X0.438 Y-0.438 F1500
G03 X0.438 Y0.438 Z0.075 I0 J0.438 F375
G03 Z0.6 I-0.875 J0 F750
G03 Z0.6 I-0.875 J0
G03 Z0.6 I-0.875 J0
G03 Z0.6 I-0.875 J0
G03 Z0.6 I-0.875 J0
G03 Z0.6 I-0.875 J0
G03 Z0.6 I-0.875 J0
G03 Z0.6 I-0.875 J0
G03 Z0.6 I-0.875 J0
G03 Z0.6 I-0.875 J0
G03 X-0.438 Y0.438 Z0.075 I-0.438 J0
G01 G40 X-0.438 Y-0.438 F2000
G90 G00 Z20.0
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.)
%

Start typing and press enter to search

Scroll to Top