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Get the Standard Dimensions for Set Screws

The standard machine screws used across the industry can be classified in two categories:
1. Counter shank Socket Cap Screw (Flat headed Counter shank)
2. Socket head cap screw (without counter shank)
The important metric screw dimensions for the above two types of machine screws are shown below:
1. Counter shank Socket Cap Screw (Flat headed Counter shank):

 

 

 

 

 

 

 

 

 

 

 

Fig.1: Showing Counter Shank Screw Dimensions

Relate the above figure (Fig.1) with the below metric screw dimensions table (Fig.2) for counter shank screw to get the dimension values of your choice of screws:

Fig.2: Counter shank socket cap screw dimensions:

Nominal Screw Thread Size Thread pitch Maximum Head Diameter (A) Nominal Hexagonal Socket Size (B) Length (C) Socket Engagement Length (D) Maximum Body Diameter (E) Minimum Body Diameter (E) Head Height (F)
M3 0.5 6.72 2 As per requirement 1.05 3 2.86 1.86
M4 0.7 8.96 2.5 As per requirement 1.49 4 3.82 2.48
M5 0.8 11.2 3 As per requirement 1.86 5 4.82 3.1
M6 1 13.44 4 As per requirement 2.16 6 5.82 3.72
M8 1.25 17.92 5 As per requirement 2.85 8 7.78 4.96
M10 1.5 22.4 6 As per requirement 3.6 10 9.78 6.2
M12 1.75 26.88 8 As per requirement 4.35 12 11.73 7.44
M16 2 33.6 10 As per requirement 4.89 16 15.73 8.8
M20 2.5 40.32 12 As per requirement 5.49 20 19.67 10.16
Alternatively, you can use the following counter shank cap screw calculator for getting the different dimensions.
counter shank socket head cap screw calculator:
Choose the nominal screw thread size, for which you want to see the dimension details:
Choose thread size:
Output Section

Thread pitch:

Max. Head Dia.(A):
Nominal Head Socket size(B):
Length (C):
Socket Engagement Length (D):
Max. Body Dia.(E):
Min. Body Dia.(E):
Ref. Head height.(F):

Notes:

  • Only few important  counter shank socket cap screw (flat headed countershank) dimensions are shown above based on ASME/ANSI B18.3.5M  and BS EN ISO 10642:1998. For more details refer the standards.
  • All dimensions are in mm.

 

 

 

2. Socket head cap screw (without counter shank)
 

 

 

 

 

 

 

 

 

Fig.3: showing Metric Socket head cap screw (without countershank)

 

Relate the above figure (Fig.3) with the below metric socket head cap  screw dimensions table (Fig.4) for non-counter shank screw to get the dimension values of your choice of screws:
Fig.4: Non-counter shank socket cap screw dimensions:

Nominal Screw Thread Size Thread pitch Maximum Head Diameter (A) Minimum Head Diameter (A) Nominal Hexagonal Socket Size (B) Length (C) Socket Engagement Length (D) Maximum Body Diameter (E) Minimum Body Diameter (E) Maximum Head Height (F) Minimum Head Height (F)
M3 0.5 5.5 5.32 2.5 As per requirement 1.5 3 2.86 3 2.89
M4 0.7 7 6.8 3 As per requirement 2 4 3.82 4 3.88
M5 0.8 8.5 8.27 4 As per requirement 2.5 5 4.82 5 4.86
M6 1 10 9.74 5 As per requirement 3 6 5.82 6 5.85
M8 1.25 13 12.7 6 As per requirement 4 8 7.78 8 7.83
M10 1.5 16 15.67 8 As per requirement 5 10 9.78 10 9.81
M12 1.75 18 17.63 10 As per requirement 6 12 11.73 12 11.79
M16 2 24 23.58 14 As per requirement 8 16 15.73 16 15.76
M20 2.5 30 29.53 17 As per requirement 10 20 19.67 20 19.73
M24 3 36 35.48 19 As per requirement 12 24 23.67 24 23.7
M30 3.5 45 44.42 22 As per requirement 15 30 29.67 30 29.67
Alternatively, you can use the following non-counter shank cap screw calculator for getting the different dimensions.
without counter shank socket head cap screw calculator:
Choose the nominal screw thread size, for which you want to see the dimension details:
Output Section

Thread pitch:

Max. Head Dia.(A):
Min. Head Dia.(A):
Nominal Head Socket size(B):
Length (C):
Socket Engagement Length (D):
Max. Body Dia.(E):
Min. Body Dia.(E):
Max. Head height.(F):
Min. Head height.(F):

Notes:

  • Only few important  Socket head cap screw (Non- countershank) dimensions are shown above based on ASME/ANSI B 18.3.1M and BS EN ISO 4762 BS 3643- 2 & BS 4168. For more details refer the standards.
  • All dimensions are in mm.

 

References:
http://www.mjvail.com/holokrome/dimensional.html

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Shibashis Ghosh

Hi, I am Shibashis, a blogger by passion and an engineer by profession. I have written most of the articles for mechGuru.com. For more than a decades i am closely associated with the engineering design/manufacturing simulation technologies. I am a self taught code hobbyist, presently in love with Python (Open CV / ML / Data Science /AWS -3000+ lines, 400+ hrs. )

This Post Has 4 Comments

  1. suvo August 25, 2011 Reply

    great article

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  2. rik August 27, 2011 Reply

    gud one

  3. Ahmed Alhassan KInbokun February 26, 2013 Reply

    pls sir, student from federal university of technology minna, engineering student. 300l agric and bio resources, sir i want to lern how i can prove virios formular for polar moment of inertia of a weled jiont.

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