Calculate the theoretical minimum required thread engagement length for blind hole and through hole applications.

Based on VDI 2230:2014

Joint Type

Screw Selection Screw


Counter Threaded Part
Data for calculation
Rm, screw N/mm²
Rm, material internal thread N/mm²
Tau, screw N/mm²
Tau, internal thread N/mm²
Breaking force, bolt N
Stripping force, internal thread N
Effective engagement length, mges vorh mm

Calculated minimum engagement length needed, mges I: mm


Material Rm, N/mm2
16MnCr5 1000
21CrMoV5-7-QT 700
25CrMo4-QT 600
30CrNiMo 8 1250
34CrMo 4 1000
34CrNiMo 6 1200
35B2-QT 500
35NiCr18 1270
38MnSi-VS 5 900
40CrMoV4-6-QT 850
41Cr4 1100
42CrV 6 1080
42CrMo4 1000
42MnV7 980
48CrMo4 880
50MnSi4 830
58CrV 4 1320
C35E-QT 500
C45E-QT 560
Cq 45 700
E295 470
S235 JRG1 340
S355 JO 510
Aluminium/ Aluminium Alloy
AW-5083 260
AW-6082 290
AW-7075 540
AlMgSi1F28 260
AlMg4,5MnF27 260
AlMgSi1F31 290
AlZnMgCu1,5 540
G-AlSi10Mg 220
G-AlSi7Mg0,3 230
G-AlSi9Cu3 160
GD-AlSi9Cu3 240
GK-AlSi7Mg wa 250
GK-AlSi9Cu3 180
Magnesium Alloy  
AZ91 310
GK-AZ91-T4 240
MgAl9Zn1 200
MgAl4Si 190
Copper/ Copper Alloy
G-CuAl10Ni 600
G-CuSn5ZnPb 220
G-CuSn7ZnPb 240
GD-CuZn37Pb 280
GK-CuZn37Pb 280
GZ-CuSn7ZnPb 270
Cast iron
GJL-250 250
GJS-400-15 400
GJS-500-7 500
GJS-600-3 600
GJV-300 300
GJV-500 500
Titanium/ Titanium Alloy
TiAI6V4 890
Nickel/ Nickel Alloy
NiCr15Fe7TiAl 1000
NiCr20TiAl 1000
Stainless steel
X10CrNiMoMnNbVB15-10-1 650
X19CrMoNbVN11-1-QT 900
X22CrMoV12-1-QT 800
X2CrNi18-9 450
X2CrNiMo17-12-2 500
X2CrNiMoN17-13-3 580
X3CrNiCu18-9-4 450
X3CrNiMoBN17-13-3 550
X4CrNi18-12 500
X5CrNi18-10 500
X5CrNiMo17-12-2 500
X6CrNi18-10 500
X6CrNiMoB17-12-2 490
X6CrNiTiB18-10 490
X6NiCrTiMoVB25-15-2 900
X7CrNiMoBNbl6-16 650

This calculation is theoretical and has to be verified by tests!

The thread engagement length will often in praxis be reduced due to run-in and run-out of screw and threads as well as chamfers.

Please pay attention to the definition of blind hole and through hole (you can choose this in the left top corner of application). Through holes are calculated without none-effective thread end and it is a prerequisite that the screw-end protudes with two thread pitches minimum (2P)

If an actual though hole application cannot fulfil the above definition, then a calculation as blind hole application is recommended instead.

Effective engagement length, mges vorh, represents the actual engagement of threaded screw/nut threads.

The calculated minimum engagement length needed must be larger than the thread engagement length defined by the user. It includes run-in and run-out of screw and nut threads and reduced contact at the thread entrance due to a slight chamfer.

Verify your calculation, maximize potential of your product.

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