ISO 4014 defines hexagon head bolts with partial thread. In everyday purchasing, many buyers also call them metric half-thread hex bolts. They are widely used in machinery, steel structures, equipment frames, brackets, and general industrial assemblies where a smooth shank is needed through part of the joint.

ISO states that ISO 4014 covers hexagon head bolts from M1.6 to M64, with product grade A for smaller and shorter bolts, and product grade B for larger or longer bolts. Buyers should treat ISO 4014 as a dimensional standard, then separately confirm material grade, coating, inspection, and nut or washer requirements.

For supply reference, XZ Fastener lists DIN 931 / ISO 4014 hex head bolts and standard fastener options covering DIN, ISO, ASTM, ANSI, and custom requirements.

What Is an ISO 4014 Bolt?

A hex head bolt with partial thread

An ISO 4014 bolt has a hexagon head, a plain shank section, and a threaded end. This is different from ISO 4017, which refers to fully threaded hexagon head screws.

The plain shank can help with alignment, shear bearing, and joint stability when the unthreaded section passes through the clamped parts.

Key ISO 4014 Dimensions

Do not check only diameter and length

When inspecting ISO 4014 bolts, diameter and total length are not enough. The thread length, shank length, head height, width across flats, and chamfer also affect assembly.

For hex bolts, length is normally measured from under the head to the end of the bolt. This matters when buyers compare ISO 4014 with custom drawings or mixed-standard parts.

ISO 4014 vs DIN 931

Similar, but not always identical in purchasing

ISO 4014 and DIN 931 are commonly cross-referenced. In many commercial fastener catalogs, they are supplied together as DIN 931 / ISO 4014. Still, buyers should be careful with wrench size and head dimensions.

Some references note that DIN 931 and ISO 4014 are partial-thread hex bolts, while DIN 933 and ISO 4017 are full-thread hex bolts. They also note head width differences for selected metric sizes such as M10, M12, M14, and M22.

If the project drawing says ISO 4014, do not replace it with DIN 931 without confirming head dimensions, wrench clearance, and customer approval.

Material Grade and Finish

ISO 4014 does not decide everything

ISO 4014 defines the bolt form and dimensional characteristics. It does not, by itself, complete the purchase specification. Buyers still need to define property class, material, surface finish, and certificate requirements.

Common options include:

• Carbon steel Class 4.8, 8.8, 10.9, or project-specified grade.
• Stainless steel A2 or A4 for corrosion resistance.
• Zinc plated, black oxide, hot-dip galvanized, or other finish.
• Nuts and washers matched by standard and strength.

For material selection, see XZ Fastener’s carbon steel fasteners and stainless steel fasteners.

Buyer Checklist for ISO 4014 Bolts

Send a complete RFQ

A clear ISO 4014 RFQ should include:

1. Standard: ISO 4014, or DIN 931 / ISO 4014 if accepted.
2. Size: diameter, pitch, and length.
3. Thread length requirement if critical.
4. Property class or material grade.
5. Surface finish and corrosion requirement.
6. Nut and washer standards.
7. Quantity and packing method.
8. Certificate requirement, such as MTC or EN 10204 3.1.
9. Drawing or application notes if the joint is critical.

For custom sizes, coated bolts, or project-based bolt assemblies, send specifications through XZ Fastener Contact Us.

Final Recommendation

ISO 4014 bolts are the correct choice when a metric hex head bolt with partial thread is required. The smooth shank can be useful where the joint needs alignment, bearing support, or a cleaner grip area than a fully threaded bolt.

Before ordering, confirm the exact standard, diameter, pitch, length, thread length, property class, coating, nut, washer, and certificate requirement. For partial-thread bolts, the shank and thread length are just as important as the overall size.