Inputs
Nominal size (M5 to M24, product class A) and nominal length l under the head.
Bolts · dimensions
ISO 4017 Full-Thread Hex Bolt Dimensions
ISO 4017 standardizes full-thread hex bolts: unlike ISO 4014, there is no smooth shank -- the thread runs up to within a short incomplete-thread run-out a of the head. This calculator returns the head and key dimensions plus the minimum length of fully-formed thread (l − a_max), relevant for the available clamped length in thin joints.
Partial-thread version with a smooth shank: ISO 4014 dimensions. Tightening torque: Tightening Torque.
ISO4017
02
Standard dimensions
Enter nominal size and length.
Inputs and method
Size a full-thread bolt to ISO 4017
Determine head, key and incomplete-thread run-out dimensions of a full-thread bolt from nominal size and length.
Calculation
A pure table lookup from Table 1 (M5-M12) and Table 2 (M14-M24) of the standard. The incomplete thread run-out a follows the footnote relation confirmed in both tables, a_min=1·P and a_max=3·P; full-thread length follows as l−a_max, all other dimensions are tabulated directly.
Example
M10x30: width across flats s=16.00 mm, head height k=6.4 mm, incomplete thread run-out a between 1.5 mm and 4.5 mm, so at least 25.5 mm of load-carrying full thread.
Sources and limits: ISO 4017:2022, Tables 1 and 2 with footnote b.
Size a full-thread bolt to ISO 4017 in detail
Determine head, key and incomplete-thread run-out dimensions of a full-thread bolt from nominal size and length.
Why is there no smooth shank on a full-thread bolt?
ISO 4017 standardizes hex bolts whose thread runs almost up to the head at every standard length. Directly under the head only a short incomplete thread run-out a remains, where the flanks have not yet reached full profile depth -- this zone does not carry full load. Unlike ISO 4014, thread length therefore effectively grows with every overall length; there is no defined smooth shank section for shear planes or close fits.
Formula and variables
A pure table lookup from Table 1 (M5-M12) and Table 2 (M14-M24) of the standard. The incomplete thread run-out a follows the footnote relation confirmed in both tables, a_min=1·P and a_max=3·P; full-thread length follows as l−a_max, all other dimensions are tabulated directly.
Choose the inputs correctly
Nominal size (M5 to M24, product class A) and nominal length l under the head.
How to use the calculator
Enter nominal size and the desired overall length. The calculator returns head and key dimensions plus the run-out range and the resulting minimum full-thread length.
Worked example
M10x30: width across flats s=16.00 mm, head height k=6.4 mm, incomplete thread run-out a between 1.5 mm and 4.5 mm, so at least 25.5 mm of load-carrying full thread.
What does the reported full-thread length mean?
The full-thread length (l−a_max) is the calculated guaranteed minimum length carrying a fully-formed thread profile -- it assumes the worst-case (longest) permissible run-out. This value matters for the clamp-length calculation to VDI 2230 when checking whether enough load-carrying thread engages the nut or internal thread. The actual run-out of a specific bolt lies between a_min and a_max and cannot be narrowed further without manufacturing data.
All dimensions in millimetres.
Typical applications
Determining available engagement depth in thin components, selecting the correct tool size for assembly, distinguishing from ISO 4014 when designing shear connections.
Assumptions, limits and common mistakes
ISO 4017:2022, Tables 1 and 2 with footnote b.
Common mistake: Don't assume the entire length l is load-carrying thread -- the run-out a (up to 3·P) does not carry full load and must be subtracted when calculating effective engagement depth.
Frequently asked questions
When do I use ISO 4017 instead of ISO 4014?
Whenever no smooth shank section is needed -- for example in thin clamped joints where as much load-carrying thread as possible is wanted, or when the chosen length is already shorter than the ISO 4014 thread length b.
How long is the incomplete thread run-out a?
It lies between a_min = 1·P and a_max = 3·P, where P is the thread pitch -- for M10 (P=1.5 mm) that's between 1.5 mm and 4.5 mm, regardless of the bolt's overall length.