Yongji Precision Hardware Co., Ltd. is a China-based Custom Fasteners manufacturer producing special screws, studs, nuts, standoffs and screw-washer assemblies from M0.8 to M16. We build parts from customer drawings, samples and application requirements, then scale them from prototype quantities to stable mass supply.
What We Manufacture in This Range
Our custom fastener range covers cold-headed screws and bolts, cam-lathe-turned precision parts, stamped nuts and clips, and assembled screw-washer combinations. The work is organized around the geometry and function of the part rather than a fixed catalogue: thread form, head style, drive, washer configuration, material grade and finish are all set from the drawing or sample.
Typical parts include Special Screw / Custom Screw profiles, Double End Studs, U-Nut / Speed Nut clips, 3-Combination Screw Assembly parts and Tape & Reel Packaging for automated feeding. Each family is matched to the process that holds its tolerance and cost most efficiently.
Process Fit: Choosing the Right Route
Cold heading is our primary route for high-volume screws, bolts, nuts and special-shaped fasteners. Single and two-die machines cover M0.8–M3 up to 30 mm, multi-station cold formers handle M4–M16 with a maximum forming length of 190 mm, and dedicated nut machines produce M2–M14 nuts. Cam lathe turning takes over where cold heading cannot reach: stepped screws, eccentric grooves, micro holes, non-standard internal and external threads and multi-step shafts, with outer diameters from Φ1.0 to 32 mm and total lengths from 1.5 to 200 mm.
Stamped elements such as U-nuts, speed nuts and clips are produced on 80T–300T servo presses from 0.15–3 mm sheet. When a part combines a headed body with a stamped washer or clip, we plan the two operations together so the assembly seats correctly and does not loosen in service.
Materials, Strength and Finishes
We process low carbon steel, medium carbon steel, 40Cr/SCM435 alloy steel, SUS304 and SUS316 stainless steel, H59 brass and 6063/6061 aluminium alloy, with small-batch titanium turning available. Incoming material is checked by spectrometer sampling before release to production.
- Strength classes: 4.8, 8.8, 10.9 and 12.9 high-strength fasteners.
- Heat treatment: surface hardness HRC38–48, core HRC28–48, carburised layer 0.003–0.005 mm.
- Finishes: electro-galvanising, zinc-nickel, black oxide, Dacromet, anodising, PVD and pre-applied Nylok adhesive.
- Corrosion: standard finishes reach 72–500 hours neutral salt spray; longer-specification anti-corrosion processes are available for harsh environments.
Our Custom Fastener Range
| Product Family |
Typical Parts |
Application Fit |
| Threaded fasteners |
Special screws, Phillips flat head, hexagon flat head, set screws, anti-loosening screws |
Electronics enclosures, chassis, appliances, general assembly |
| Studs and bolts |
Fully threaded studs, double end studs, U-bolts, assembly bolts, shoulder screws |
Energy storage racks, structural joints, pipe and channel fixing |
| Nuts and inserts |
U-nut / speed nut, brass insert nut, embedded nut |
Sheet metal panels, plastic housings, telecom cabinets |
| Standoffs |
Male-female, female-female and hex standoffs |
PCB mounting, control panels, instrument stacks |
| Screw-washer assemblies |
3-combination screw assembly, self-tapping screw with washer, washer head self-tapping screw |
Batch assembly lines where loose washers slow the station |
| Packaging format |
Tape & reel packaging for M0.8–M10 micro screws, rivets, pins and washers |
SMT pick-and-place and automated feeding lines |
Tolerances and Repeatability
Tolerance is agreed per feature, not as a single blanket figure. Our working capability is ±0.01 mm for conventional mass-produced turned parts, down to ±0.003 mm for high-precision custom parts, ±0.05 mm for stamping and bending, and approximately ±0.1 mm for cold-formed features. Thread gauging, torque testing and dimensional inspection confirm that the delivered parts hold the drawing across the run.
Quality Control and Acceptance
An independent enclosed testing laboratory supports incoming material inspection, in-process patrol inspection and finished product final inspection across all four production workshops. Equipment includes Zeiss 3D CMM, 2.5D optical vision measuring machines, automatic CCD sorters, contour and roughness testers, universal tensile testers, torque testers, Rockwell and Vickers hardness testers, salt spray chambers, an optical emission spectrometer, metallographic microscope and XRF RoHS screening.
- Documents available on request: material certificates, full-dimensional inspection reports, salt spray reports, mechanical test reports, RoHS certificates, 8D improvement reports and PPAP documentation.
- Systems: IATF16949, ISO9001, ISO14001, ISO45001 and QC080000; testing instruments are third-party calibrated annually.
- Sampling plans can follow the customer's AQL standard, and test schemes can be aligned to overseas internal inspection standards.
Information We Use to Configure Your Solution
A quotation is only meaningful once the working point is clear. We review the following inputs before proposing a process route, tooling plan and price:
- 2D drawing or 3D model, plus a physical sample where available.
- Material and strength class, and the mating part or host material.
- Critical dimensions, thread specification and the tolerances that actually matter.
- Surface finish and the corrosion or salt spray target.
- Assembly method, drive type and any automated feeding requirement.
- Annual volume, first order quantity and expected call-off pattern.
- Packaging format, labelling and delivery destination.
From Prototype to Mass Production
We support prototype development, engineering validation, pilot production and mass production within one workflow. Prototypes and small high-precision batches are handled at our Suzhou plant; volume fastener production runs across the Suzhou and Vietnam cold heading lines, with stamping capacity in Yangzhou and Vietnam. This structure lets a program start small for validation and move to stable supply without changing the engineering contact.
Frequently Asked Questions
What size range can you manufacture?
Cold heading covers M0.8 to M16, with M0.8–M3 parts up to 30 mm and M4–M16 parts up to 190 mm forming length. Nuts run from M2 to M14. Turned parts cover Φ1.0–32 mm outer diameter and 1.5–200 mm total length.
Can you produce from a sample instead of a drawing?
Yes. We reverse-engineer the geometry from a sample, confirm the material and finish with you, and issue a drawing for approval before tooling or production begins.
Which materials and finishes are available?
Low carbon, medium carbon and 40Cr/SCM435 alloy steel, SUS304/SUS316 stainless steel, H59 brass and 6063/6061 aluminium, with small-batch titanium turning. Finishes include electro-galvanising, zinc-nickel, black oxide, Dacromet, anodising, PVD and pre-applied Nylok adhesive.
Do you supply tape and reel packaging for automated assembly?
Yes. Carrier tape widths from 8 mm to 200 mm, pocket sizes matched to the fastener, and 7-inch, 13-inch or 15-inch reels compatible with SMT pick-and-place equipment. Peel force is controlled within the EIA range.
What documentation accompanies a shipment?
Depending on the part and program, we issue material certificates, dimensional inspection reports, salt spray and mechanical test reports, RoHS certificates and PPAP documentation. Sampling can follow your AQL plan.
How do I start a project?
Send the drawing or sample together with material, finish, volume and packaging requirements. Our engineering team reviews the part, confirms the process route and returns a configuration and quotation. Browse the full Products range or contact our team directly to begin.
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