Industrial Fasteners Manufacturer for OEM & Custom Builds
From pressure-equipment bolting to production-line assemblies, Sunhy supplies precision fasteners built to spec. Choose carbon/alloy steel, stainless (304/316), or performance alloys such as Duplex 2205, Titanium Grade 5 and Inconel 625. Each order can be supported with lot traceability and inspection records to meet audit and compliance needs.
EN 10204 3.1 / MTC available on request
Heat / lot traceability from raw material to packing
Incoterms support: FOB / CIF / DDP
M3–M64
Metric coverage +
common inch ranges
Up to 12.9
High-tensile alloy
steel options
Zinc Flake
Designed to
reduce embrittlement risk
Choose Fasteners by Standard, Size & Function
Use this quick selector to navigate common industrial fasteners by DIN / ISO / ANSI references. You can start from a standard part number, filter by size range and strength class, then confirm finish and inspection requirements before requesting a quotation.
Socket & Machine Screws
Allen / Torx / countersunk / button head families—pick by standard and head type for assembly access and appearance.
- ISO 4762 / DIN 912 (Socket Head Cap)
- ISO 7380 (Button Head / Flange Button)
- DIN 7991 / ISO 10642 (Countersunk)
- Fine pitch & security drive options
- Electropolish / zinc / zinc flake options (as required)
Hex Bolts & Fit Bolts
Coarse/fine thread hex bolts and fit bolts—organized by forming route and size range for your BOM.
- DIN 931 / DIN 933 (Hex bolt coarse thread)
- Fine thread series (by DIN/ISO spec)
- Fit bolts / precision shank options
- Hot forging range for larger diameters
- Optional coating + hardness verification
Nuts, Washers & Studs
Build complete assemblies with matching nuts, washers, and studs—selected by standard and property class.
- DIN 934 / ISO 4032 (Hex nuts)
- DIN 985 / DIN 982 (Nyloc nuts)
- DIN 125 / ISO 7089 (Plain washers)
- DIN 127 (Spring washers)
- Studs: DIN 835 / DIN 938 / DIN 939
Pins, Plugs & Special Items
Positioning pins, threaded plugs, and functional specials—choose by tolerance/fit and application.
- Clevis pins (DIN 1444 / ISO 2341)
- Dowel pins (h6/m6 options as specified)
- Taper / socket / hex plugs (by standard)
- Knurled thumb screws / knurled nuts (DIN 464/467/466)
- Grinding/oil finish for pin families (by requirement)
Metallurgical Excellence
Facilities, Inventory & Traceability
Our production and warehouse system is built for OEM reliability: controlled incoming inspection, clearly identified lots, and packing labels that support traceability through shipment. We keep common industrial fasteners ready for quick dispatch and support made-to-print projects with dedicated batch control.
Inventory Coverage: 1,500+ catalog-standard SKUs available (metric & inch series)
Size Range: M3–M64 / 1/4″–2″ (common sizes)
Strength Grades: Property Class 4.8, 8.8, 10.9, 12.9; stainless grades and special alloys available on request
Surface Finishes & Heat Treatment
Select coatings and heat treatment routes based on corrosion targets, friction requirements and embrittlement risk. We support zinc plating, black oxide, zinc phosphate and zinc-flake systems, plus controlled heat treatment to meet mechanical property requirements.
For zinc-flake systems such as GEOMET® 500, stable friction control is achievable in defined ranges (tested per ISO 16047).
Quality Control, Testing & Inspection
Advanced testing facilities at Sunhy guarantee the highest standards of quality and performance for every product. Utilizing state-of-the-art equipment, Our Manufacturer rigorously tests fasteners to ensure they meet stringent industry specifications and exceed customer expectations.
- Hardness Testing (HRB, HRC, HV Scales)
- Yield Stress
- Proof Stress
- Ultimate Tensile Strength
- Elongation Percentage
- Bend Test
- Metallurgical Testing
- De-Carb Testing
- Micro-Structure
- Inclusion Rating
- Crack Detection
- Roughness Testing (Ra, Ry, Rz)
- Torque Testing
- Coating Thickness Testing
- Salt Spray Test
- HCL Testing
- Specific Gravity
- Concentration of HCL
- Spectrometer- For Chemical Composition
- CMM for critical dimensions
Tooling, Prototyping & Custom Fasteners
Die and tooling development for cold heading / forming
Prototype to volume production planning
Special threads, fine pitch, and application-specific geometry
Application Engineering
Materials & Grades for Demanding Environments
Choose materials to match corrosion class, temperature, and mechanical load. Beyond carbon and alloy steel, we support stainless steel and performance alloys for aggressive media and high-temperature duty. Material selection can be aligned to ASTM/DIN/ISO requirements and verified with requested certification packages.
Standard Fasteners Selector Guide
Search by standard (DIN/ISO/ANSI), product name, or keyword (flange, dowel, plug, nyloc).
| Catalog No. | Name | Category | Size | Grade | Finish | Standard | Actions |
|---|
Engineer’s Toolbox: Data Tables + Selection Notes
What “Grinding + Oil” means: controlled diameter + smooth surface, reducing galling and improving repeatable motion.
Torque note: follow shoulder-spec torque guidance to avoid failure from over-tightening.
| Shoulder Dia d1 (f9) | Thread Size d2 | Head Dia d3 | Common Shoulder Lengths l1 (mm) | Recommended Torque Limit (Nm) |
|---|
Procurement note: ask for document scope (e.g., EN 10204 3.1 / inspection report) in RFQ.
| Thread | Pitch | Height h (max) | Wrench Size s | Insert | Class |
|---|
| Nominal Dia | m6 Tolerance (μm) | h6 Tolerance (μm) | Hardness (HRC) | Case Depth |
|---|
| Thread | Flange Dia dc (max) | Wrench Size s | Head Height k | Tensile Strength (10.9) |
|---|
| Thread (d1) | Drive (s) | Collar Dia (d2) | Recommended Sealing Ring | Weight (g) |
|---|
Salt spray hours depend on spec, thickness, and test standard (e.g., ISO 9227 / ASTM B117). Use your validated internal test targets in RFQ.
| Coating Type | Salt Spray (Red Rust) | Thickness | Embrittlement Risk | Primary Use Case |
|---|
Typical Applications & Case Examples
Two examples below show how we translate requirements into a controllable process, with traceability and deliverables. Final specifications are confirmed per customer drawings and applicable standards.
Case 1 — Pressure equipment / flange joint bolting (high reliability)
Customer requirement: High-strength bolts for critical flange joints; full lot traceability; required certificates (e.g., EN 10204 3.1).
Our proposal: Confirm standard (DIN/ISO/ANSI), size, thread, strength class, heat treatment route, and surface protection based on the environment.
Process control highlights: Material heat/lot tracking → controlled heat treatment → hardness & mechanical tests → dimensional inspection → marking/packing with lot ID.
Deliverables: 3.1 certificate (if requested), inspection report, packing list with lot traceability, and documentation checklist for customs clearance.
Case 2 — Salt spray target + Grade 12.9 (hydrogen embrittlement risk management)
Customer requirement: Corrosion resistance target (salt spray hours) + high-tensile fasteners (12.9); minimize delayed fracture risk.
Our proposal: Prefer zinc flake systems (Geomet/Geomat-type or equivalent) when appropriate; define test method and acceptance criteria (commonly ISO 9227 / ASTM B117, per spec).
Process control highlights: Coating system selection → pre-treatment compatibility check → coating application & cure control → thickness/appearance check → corrosion test report (if requested).
Notes for 12.9: If electroplating is required by spec, we align baking / process controls to the customer’s specified standard to reduce hydrogen embrittlement risk.
Tip: For the fastest quoting, include standard, size, material/grade, finish target, quantity, destination, and required documents in your RFQ.
| Material Family | Grades Available | Key Properties & Applications |
| Stainless Steel | 304/304L (A2), 316/316L (A4), A2-70, A4-80 | Excellent corrosion resistance for general industrial and marine use. Passivated for enhanced durability. |
| Titanium Alloys | Grade 2 (CP), Grade 5 (Ti-6Al-4V) | 60% lighter than steel with superior strength. Ideal for Aerospace, Medical, and Racing applications. |
| Duplex Steel | Duplex 2205, Super Duplex 2507 | Exceptional resistance to stress corrosion cracking (SCC) and pitting. Perfect for Offshore Oil & Gas and Desalination. |
| Nickel Superalloys | Inconel 625/718, Monel 400, Hastelloy C276 | Extreme high-temperature stability and resistance to oxidizing acids. Used in Chemical Processing and Power Generation. |
Request a Quote (Attach Drawing)
Recommended: standard, size list, grade/material, finish, quantity/EAU, destination,documents, and drawing if custom.
FAQ
How do I specify fasteners for an accurate quote?
Provide standard, diameter × length, thread type (metric/UNC/UNF), material/grade, finish/coating target, quantity/EAU, destination, and required documents (e.g., EN 10204 3.1). Drawings help for custom deviations.
What does Grade 12.9 mean in real applications?
Grade 12.9 indicates a high-strength alloy steel fastener commonly used in heavy machinery, tooling and high-load assemblies. Your final selection should still consider joint design, torque guidance, and environment.
Why choose Zinc Flake (Geomet/Geomat-type) over standard zinc plating?
Zinc flake coatings can deliver significantly higher corrosion resistance targets (often hundreds to 1000+ hours depending on spec), and can reduce hydrogen embrittlement concerns for high-tensile fasteners versus some electro-plating processes.
Are Nyloc nuts suitable for high temperature?
Nylon insert lock nuts are typically rated up to around 120°C. For higher temperature environments, request all-metal locking nuts.
Can I reuse Nyloc nuts?
They can be reused, but prevailing torque reduces with repeated cycles. For critical safety joints, consider single-use or define a reuse limit.
Can you support DDP shipments and compliance documents?
We can support Incoterms planning (FOB/CIF/DDP) and prepare a documentation checklist for customs clearance. Share destination and compliance needs in your RFQ.