Most wind turbine fastener projects require something beyond catalogue stock — a non-standard length, a specific coating combination, private-label packaging for an O&M service company, or a drawing-to-sample reproduction of a legacy bolt. We manufacture to specification, not from a fixed catalogue.
§ 01 OEM vs ODM — What the Terms Mean in Fasteners
OEM (Original Equipment Manufacturer) supply means we manufacture to your drawing and specification, and ship under your brand or neutral packaging. The product design is yours; we produce it. This is the standard model for turbine OEMs, tower fabricators, and O&M companies that need fasteners to a closed engineering specification with full material traceability.
ODM (Original Design Manufacturer) supply means we contribute to the product design — you describe the application requirements (load, environment, corrosivity, access constraints) and we recommend the grade, coating, geometry, and assembly configuration. You review and approve the design before production. This suits distributors, EPC contractors, and project developers who need a complete fastener specification but do not have an in-house fastener engineering team.
§ 02 What We Can Manufacture to Custom Specification
| Product Type | Custom Parameters Supported | Applicable Standards |
|---|---|---|
| Tower flange bolts (hex) | Diameter M16–M72, length 60–800 mm, thread reach, grip length, any ISO pitch | EN 14399-3/4, ISO 898-1 |
| Foundation anchor studs | Diameter M36–M80, length up to 4000 mm, double-end thread, partial thread, L-end | ISO 898-1, ASTM F1554 |
| Blade root T-bolt studs | To blade drawing: diameter, thread form, length, material grade, surface finish | ISO 898-1, OEM drawing |
| Nuts and washers | Standard and non-standard dimensions, hardened, flanged, serrated, custom material | EN 14399-6, ISO 4032/4033 |
| Coatings | Zinc-flake (Geomet, Dacromet), HDG, zinc-nickel, passivated stainless, PTFE topcoat | ISO 10683, ISO 10684 |
§ 03 The Custom Specification Process
For OEM orders, the process is straightforward:
- Submit drawing or specification — PDF drawing with GD&T tolerances, or a written spec referencing applicable standards plus deviations. If you have a sample bolt, we can reverse-engineer to drawing.
- First-article inspection (FAI) — we produce 3–5 sample pieces, prepare a full dimensional and material certificate report, and submit for your approval before production run.
- Production with 100% traceability — each production batch gets a unique heat number, dimensional inspection record, and EN 10204 Type 3.1 material certificate (or 3.2 on request for offshore-critical applications).
- Packaging and labelling to your spec — private label, customer part number, RFID tags, or Kanban bin labelling for O&M inventory systems.
For ODM projects, we begin with an application questionnaire: turbine class, connection location, design life, corrosivity category, maintenance access frequency, and structural standard (EN or ASTM). We issue a fastener recommendation package — grade, coating, dimensions, and torque/preload targets — for your engineering sign-off before FAI.
§ 04 Documentation Package
Standard documentation for every OEM/ODM order:
- EN 10204 Type 3.1 material certificate — chemical composition and mechanical properties from the steel mill, countersigned by our QC. Traceable to production batch and heat number.
- Dimensional inspection report — 100% of critical dimensions per drawing, sampled per ISO 2859 AQL 1.0 for non-critical dimensions.
- Coating certificate — salt-spray test hours per ISO 9227, coating thickness per ISO 2178 (magnetic) or cross-section, adhesion per ISO 2409.
- Hardness test records — Vickers or Rockwell per ISO 6507/6508, frequency per property class standard.
- CE Declaration of Performance — for EN 14399 bolt assemblies used in CE-marked structures under EN 1090.
For offshore-critical applications (CX / splash zone, NACE sour service), we provide EN 10204 Type 3.2 certificates (third-party witness) and can arrange DNV / Bureau Veritas / Lloyd's Register inspection at our facility.
§ 05 MOQ and Lead Times
| Product | Typical MOQ | Standard Lead Time | Expedited Available |
|---|---|---|---|
| Stock-range tower bolts (M20–M42) | 100 pcs | 7–14 days | Yes, 3–5 days |
| Custom length tower bolts | 200 pcs | 21–35 days | 14 days for repeat orders |
| Large anchor studs (M52+) | 50 pcs | 28–45 days | Subject to bar stock availability |
| Stainless / duplex grades | 50 pcs | 21–42 days | Limited — inquire |
Lead times above assume approved drawings and standard coatings. Third-party inspection (3.2 certs) adds 5–7 days. For ongoing O&M supply programs, we offer blanket order agreements with pre-agreed pricing, reserved production slots, and consignment stock at your warehouse — eliminating emergency procurement lead times entirely. Contact us to discuss a supply program tailored to your fleet maintenance schedule.