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ISO 4014 vs ISO 4017 comes down primarily to thread coverage. ISO 4014 specifies hexagon head bolts with a defined unthreaded shank when the selected size and length permit it. ISO 4017 specifies hexagon head screws with threads extending along the usable body, apart from the permitted incomplete thread near the head. Both cover steel and stainless steel fasteners with metric coarse threads, but they should not be substituted solely because their nominal diameter and length match.
Contents
The standards use different formal names: ISO 4014 covers hexagon head bolts, while ISO 4017 covers hexagon head screws. In everyday purchasing, both may be called “hex bolts.” The standard number removes that ambiguity.
| Selection point | ISO 4014:2022 | ISO 4017:2022 |
|---|---|---|
| Formal product description | Hexagon head bolts | Hexagon head screws |
| Typical thread coverage | Defined thread length, leaving an unthreaded shank when size and length allow | Threads along the usable body, subject to the permitted incomplete thread |
| Typical selection reason | The assembly drawing requires an unthreaded portion at a specified location | The assembly needs thread engagement over a greater portion of the fastener length |
| Thread series within scope | Metric coarse pitch, M1.6 to M64 | Metric coarse pitch, M1.6 to M64 |
| Materials within scope | Steel and stainless steel | Steel and stainless steel |
| Product grades | A and B | A and B |
Do not confuse product grade A or B with mechanical property class 8.8 or 10.9. The product grade concerns dimensional tolerances. Material and mechanical properties must be specified separately for the intended application.
A drawing may require an unthreaded shank to pass through particular components or across a shear plane. In that case, the buyer must check the actual shank length for the specified diameter and nominal length. Calling a bolt “partially threaded” is not enough: the smooth portion must be in the required position after washers, plates and other joint components are assembled.
A fully threaded ISO 4017 fastener may be useful when a tapped component needs engagement at a particular depth, or when the available grip length varies. It does not automatically provide the same joint behavior as an ISO 4014 bolt. The designer still needs to check thread engagement, clearance, preload requirements and the position of any shear plane.
For both standards, nominal length is measured from beneath the hexagon head to the end of the fastener. Two items described only as “M12 × 80” can therefore have the same nominal diameter and length while presenting different thread coverage. The example identifies a size for discussion; it does not establish that every proposed material, property class or configuration is available.
For an ISO 4014 bolt, check the standard’s thread-length requirements for the exact diameter and length. For ISO 4017, “fully threaded” is a practical description, but it should not be interpreted as a promise of complete thread form directly against the underside of the head.
Start with the assembly drawing and the fastener’s position in the completed joint. The following questions make the choice more reliable than selecting from a product photo.
| Assembly question | What to verify |
|---|---|
| Must a smooth shank pass through part of the joint? | Specify the required unthreaded length and confirm the selected ISO 4014 size provides it. |
| Will the fastener enter a tapped or blind hole? | Check required thread engagement, entry clearance and remaining space at the bottom of the hole. |
| Will a nut be used? | Confirm that sufficient usable thread remains after accounting for the joint grip, washers and nut. |
| Does a shear plane cross the fastener? | Confirm whether it crosses the shank or the threaded section, then assess the joint under its design requirements. |
| Does the drawing cite another standard? | Compare dimensions, tolerances and the specified edition before proposing a substitution. |
The smooth shank of an ISO 4014 bolt can be relevant where the drawing requires a defined bearing section. An ISO 4017 screw provides more threaded length for certain assembly arrangements. Neither description alone establishes allowable load, clamp force, fatigue performance or suitability for a safety-critical joint.
ISO 4014 or ISO 4017 identifies a dimensional product standard. A usable purchase specification also needs the material and mechanical requirements. For steel fasteners, the relevant property class may be selected under ISO 898-1. For corrosion-resistant stainless steel fasteners, the grade and property class may be selected under ISO 3506-1, subject to the project specification.
Finish is another separate decision. An order for zinc-plated carbon steel, for example, needs a defined coating requirement rather than an assumption based on the hex head shape. If the assembly involves a coated bolt and nut, confirm the mating thread fit after coating.
For replacement parts, compare more than the nominal size. Check the standard edition, thread pitch, head and bearing dimensions, thread length, end form, tolerances, material, mechanical properties and finish. A drawing that cites DIN 931 or DIN 933 should be reviewed dimension by dimension before an ISO-designated item is offered as a substitute.
Send the following information when requesting a quotation for hexagon head bolts and screws:
If you are comparing an existing part with a proposed replacement, include the original drawing or a clear dimensioned sketch. IIIBEAR can review the requested fastener against the application and coordinate the agreed checks through its quality control process. Documentation and inspection requirements should be confirmed in the quotation.
ISO 4014 defines hexagon head bolts with a specified thread length. Whether a particular size has the unthreaded portion needed for your joint depends on its diameter and nominal length. Check the actual dimensions for the selected item.
ISO 4017 is commonly described as fully threaded. A short incomplete-thread area can remain near the head, so a design needing usable threads at an exact location should specify and verify that requirement.
Not without checking the assembly. The difference in thread coverage can change where threads or a smooth shank sit in the joint. Review the drawing, grip length, thread engagement and applicable load requirements before substitution.
No. The standards cover product geometry and related requirements for their respective fastener types. Specify a suitable mechanical property class separately under the relevant material standard and project requirements.
No automatic substitution should be assumed. DIN 931 is commonly associated with partially threaded hexagon bolts and DIN 933 with fully threaded hexagon fasteners, but the exact drawing, standard editions and dimensions must be compared before approval.
The central ISO 4014 vs ISO 4017 decision is where the joint needs usable threads and where it needs an unthreaded shank. Confirm that geometry first, then define material, property class, finish and inspection requirements. For further background, see IIIBEAR’s hex bolt selection guide.
Have a drawing or BOM ready? Send IIIBEAR your fastener inquiry with the standard, size, assembly details and document requirements so the proposed item can be reviewed against your specification.
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