Product Overview
Structural bolts hold a steel frame together, so they are the last place to save money. We supply high-strength friction-grip (HSFG) bolts to EN 14399-3 / -4 and ASTM A325 / A490, in property classes 8.8 and 10.9, from M12 to M30 - as complete assemblies with nut and washers, not as loose bolts you have to match up yourself.
These are the bolts the same fabricators buy when they buy our universal beams and columns. Kennen Steel International is a China-based steel trading company and first-tier mill agent, so the bolts come from source mills we have vetted and worked with, on our specification, and leave with mill test certificates and export documents handled as one package.
Typical orders go to steel-frame projects across Africa, Southeast Asia and the Middle East, where a full set of documentation for destination clearance matters as much as the bolt itself. Three decades of steel trading in China and a vetted network of source mills is what stands behind each consignment.
Key Advantages
Friction-grip where it counts
HSFG bolts are preloaded so the joint carries load by friction between the plates, not by bolt shear alone. That is what makes them the right choice for slip-critical connections in bridges, towers and heavily loaded frames.
Two standards, one supply chain
European EN 14399-3 (HR) and EN 14399-4 (HV), or American ASTM A325 / A490 - order to whichever standard your drawings call for, from the same supplier that already ships your sections.
Supplied as assemblies
EN 14399 bolting comes as a matched set: bolt, nut and washers together, with the lubrication specified for the system. You fit what arrives instead of chasing compatible nuts and washers from a second source.
Runs with your steel order
Bolts, nuts and washers can ship alongside your UB/UC or plate order, on one set of documents and in one container where volumes allow - fewer suppliers, less site chasing.
Finishes for the site
Plain (oiled) for indoor and painted work, or hot-dip galvanized for exposed and coastal projects, with the coating standard confirmed against your specification before the order is placed.
Technical Specifications
| Item | Specification |
|---|---|
| Product Name | Structural Bolts (HSFG, high-strength friction-grip) |
| Systems / Standards | EN 14399-3 (HR system) and EN 14399-4 (HV system); ASTM A325 / A490 |
| Property Class | 8.8 and 10.9 |
| Size Range | M12–M30 (available sizes and classes confirmed per order) |
| Delivery Form | Assemblies: bolt + nut + washers per EN 14399 (bolt-only supply on request) |
| Head / Drive | Hex head; tension-control (TC) variants subject to mill confirmation |
| Thread | Rolled thread; thread length and full/part-thread to the cited standard - confirmed per order |
| Finish | Plain (oiled) or hot-dip galvanized; coating standard confirmed per order |
| Mechanical Properties | Per property class and cited standard - tensile, proof load and hardness confirmed per batch on the mill test certificate |
| Lubrication / k-factor | As specified for the HR or HV system - confirmed per order |
| Marking | Head marking per the cited standard; traceability confirmed per batch |
| Certificate | EN 10204 3.1 mill test certificate per batch |
| Packing | Cartons, steel drums or pallets, strapped for export - confirmed per order |
Standard, class, size and finish are confirmed against your connection design and drawings before the order is placed. Where a value above is not fixed, it is settled per order rather than assumed.
Step-by-Step Manufacturing Process
- Wire rod / bar selection - alloy steel of the required grade is sourced and its chemistry checked before production. The grade sets the class the bolt can reach.
- Forming - the shank and head are formed by cold or warm forging, which keeps the grain flow continuous through the head-to-shank fillet where bolts usually fail.
- Thread rolling - the thread is rolled, not cut, so the grain is compressed rather than severed and fatigue life improves.
- Heat treatment - quench and temper is controlled to bring the bolt to property class 8.8 or 10.9 within the specified hardness band.
- Surface treatment - plain oiled finish, or hot-dip galvanizing for exposed service, with the coating checked after treatment.
- Assembly - nut and washers are matched to the bolt and the specified lubricant applied, so the assembly behaves as one system when torqued.
- Testing - hardness, tensile / proof load, dimensional and thread-gauge checks are run on samples from each batch.
- Marking and packing - head marking applied for traceability, then packing for export.
Quality Assurance & Certificates
- EN 10204 3.1 mill test certificate per batch - chemistry, mechanical properties, hardness
- Dimensional inspection and thread gauging to the cited standard
- Mechanical testing (tensile / proof load, hardness) per batch
- Third-party inspection available on request (SGS, BV, Intertek)
- Documentation support for destination conformity requirements (for example KEBS / PVoC)
- Every shipment is checked against the agreed specification before it leaves, so what lands matches what was ordered
Core Applications
- Steel frame connections - beam-to-column, bracing and splice joints
- Preloaded and slip-critical joints in bridges, towers and heavy structures
- Industrial sheds, warehouses and plant structures
- Fabricators and contractors already buying UB/UC sections and plate from us
- Projects needing galvanized fasteners for exposed or coastal conditions
FAQ
What is an HSFG bolt?
HSFG stands for high-strength friction-grip. The bolt is tightened to a controlled preload so the clamped plates carry load through friction between their faces rather than through the bolt in shear. It is the standard solution for slip-critical structural connections.
What is the difference between EN 14399-3 and EN 14399-4?
They are two systems under EN 14399: EN 14399-3 is the HR system and EN 14399-4 is the HV system. They differ in bolt, nut and washer geometry and in how the assembly is lubricated and installed. Order the system your drawings specify - we supply either.
Should I order to EN 14399 or to ASTM A325 / A490?
Whichever standard your design and local code call for. EN 14399 suits European-specified projects, A325 / A490 suits American-specified ones. Tell us the standard on the drawings and we will quote and supply to it.
Do you supply bolts with nuts and washers?
Yes. EN 14399 assemblies are supplied as bolt plus nut plus washers, matched and lubricated as a set. If you need bolts only, say so on the enquiry.
Can I get hot-dip galvanized bolts?
Yes - plain (oiled) or hot-dip galvanized, with the coating standard confirmed against your specification before the order is placed.
Do you supply tension-control (TC) bolts?
TC bolts can be sourced; availability and sizes are confirmed per order, so send the specification and let us confirm against the source mill before you commit.
Do you provide mill test certificates?
Yes. Each batch comes with an EN 10204 3.1 mill test certificate covering chemistry and mechanical properties, and third-party inspection can be arranged on request.
Can bolts ship together with our steel sections?
In most cases, yes - bolts, nuts and washers can be consolidated with your UB/UC or plate order into one shipment and one set of documents, where volumes allow. Tell us both orders and we will plan the loading.
How do you handle destination conformity requirements?
We prepare and support the documentation your destination needs - for example KEBS or PVoC - so clearance is not held up at the port. Tell us the destination and the conformity scheme in force and we will match the paperwork to it.
