Silica sol investment casting with matched CNC machining, covering a few grams to 100kg per piece. Valve parts and pipe fittings are our main output and most orders are made to customer drawings, with stable results on complex, uneven-wall parts carrying tight geometric tolerances. Once drawings are received, we issue a free castability (DFM) review before quoting.
Sanming Hongyi Technology Development Co., Ltd. was established in April 2022 at No. 55 Jingyuan Road, Shangjing Industrial Park, Shangjing Town, Datian County, Sanming, Fujian. The site covers 55 mu (about 36,700 m²) and over 100 people work here on precision investment casting and CNC machining. Three intermediate frequency induction furnaces (150kg × 2, 250kg × 1) run the silica sol casting process with spectrometer checks before tapping, supported by 16 machine tools with capability up to 5-axis. The company holds ISO 9001 (quality), ISO 14001 (environmental) and ISO 45001 (occupational health and safety) certifications. Most deliveries are valve parts, pipe fittings and custom non-standard parts made to customer drawings, shipped to Taiwan, Japan, Europe and the US.
Six capability modules cover the full chain from precision casting to machining, so any quality issue can be located and corrected inside one system.
Silica sol shell building gives strong shells and a good surface finish, suited to forming complex parts in one pass.
16 machine tools with capability up to 5-axis; casting and machining are scheduled together, so lead time and quality responsibility stay with one supplier.
Most orders are custom parts made to customer drawings; drawings or physical samples are both acceptable.
3 medium-frequency induction furnaces; we pour only after melt-side spectrometer analysis confirms the chemistry, controlling material at the source.
ISO 9001 system in operation; before shipment we check chemistry, dimensions and appearance and keep the records.
From cleaning and grinding through to export packing in one flow, with long-term supply to customers in Taiwan, Japan, Europe and the US.
The categories below are common supply examples; actual product specifications follow customer drawings.
Valve Parts
Valve bodies, bonnets, discs and handwheels. Internal cavities and flow passages are cast in one piece, then sealing faces are finish-machined on CNC.
Pipe Fittings
Elbows, tees, reducers, pipe fittings, flanges and the like. Weld-end and threaded faces machined to standard or to drawing.
Structural parts
Housings, brackets, bearing seats and box-type parts. Multiple welded or assembled parts can be merged into a single casting, removing assembly steps.
Wear Parts
Wear parts such as liners, bushings, guide plates and hammers. Carbon steel or cast steel grades, with heat treatment to your requirements.
Hardware
Furniture hardware, handrail fittings, decorative parts, fixtures and equipment accessories. Parts are assembled many-up on wax trees for good dimensional consistency.
Cast steel parts
Regular castings in 25 steel, A3, 45 steel and WCB, suited to load-bearing parts and to parts that will be quenched and tempered.
Machining
Machining-only orders are also accepted. Angled, contoured and multi-faced parts are finished in one 5-axis setup.
Custom parts
Most orders are special custom parts, developed from drawings or physical samples; a process review is issued before we quote.
The diagram below shows our main silica sol investment casting flow. Each step has its own process specification and inspection point, so abnormalities are caught before the next step.
We start with a castability review to fix draft direction, wall thickness and gating and riser positions, then build the wax mold.
Wax is injected separately on the mid-temperature and low-temperature lines; patterns are checked for completeness, then gates are welded into trees, with multi-cavity dies raising output
Silica sol as binder and zircon flour as the face coat, with layer-by-layer dipping and sanding under controlled drying humidity.
Steam dewaxing recovers the wax for reuse, and high-temperature shell burnout raises shell strength and removes residue.
Charged by grade and melted in the medium-frequency induction furnace; pouring only after melt-side spectrometer analysis confirms the chemistry.
Vibration knocks off the shell sand, castings are cut from the gating and riser, and sprue remnants are ground off.
Removes adhered sand and oxide scale for a uniform base surface.
Annealing to material and drawing requirements, relieving casting stress and stabilizing structure and hardness
Finish machining of sealing faces, threads, hole patterns and fit surfaces; complex angled parts done in one 5-axis setup.
Key dimensions checked against drawing, every finished part visually inspected, batch records kept under ISO 9001
Pickled surfaces, passivation for stainless parts, and product marking and shipping marks as the customer requires
Wooden case / pallet moisture-proof packing; export orders supported with packing lists and customs documents.
The table below lists the grades we produce routinely. For special grades or alloy steels, please send the drawing first; we reply after assessing melting and process feasibility.
| Material category | Common grades | Typical applications | Heat treatment condition | Remarks |
|---|---|---|---|---|
| Quality carbon steel / carbon steel castings | 25 steel · A3 (Q235) · 45 steel | Machine structural parts, wear-resistant parts, general hardware | Annealed / normalized + tempered | Regular parts with a balance of cost and performance |
| Cast carbon steel for general engineering | WCB | Valve bodies, bonnets, pipe fittings, flanges | Normalized + tempered | The cast steel grade most used in the valve industry |
| Stainless steel (wrought grade designation) | 201 · 202 · 304 · 304L · 316 · 316L | Valve parts, pipe fittings, corrosion-resistant parts, decorative parts | Solution annealing | Use this row when drawings cite sheet or bar grades |
| Cast stainless steel (casting grade designation) | CF8 · CF8M | As above; common for export and valve parts | Solution annealing | CF8 corresponds to 304, CF8M corresponds to 316 |
| Other materials | Special grades / alloy steel / customer-specified | Assessed case by case from the drawing | Per technical requirements | Needs a melting and process feasibility review first |
Note: for the same part, a drawing marked 304 or CF8 means different governing standards and different quoting. For export orders especially, state the grade and standard system (GB / ASTM / JIS / EN) on the drawing so everything is confirmed at once and rework in production is avoided.
Investment casting matched with machining suits parts of complex structure, defined material requirements and frequently changing specifications. The following are the directions we supply most often.
Valve bodies, bonnets, discs, handwheels and operator parts. Mostly WCB and CF8 / CF8M, with sealing faces finish-machined on CNC.
Elbows, tees, reducers, fittings and flanges. Bores are cast in one step; weld ends and threaded faces are machined to the drawing.
Corrosion-resistant piping and equipment parts, mainly 316 / 316L. Chemistry is spectrometrically verified heat by heat, and material certificates are available.
Strainer bodies, connectors, brackets and fixing parts. Specifications vary widely from drawing to drawing, which suits a made-to-drawing production model.
Sanitary-grade fittings and equipment parts in stainless steel, with polishing or pickling and passivation available.
Housings, brackets, bearing seats and box-type structural parts. Welded or assembled structures can be consolidated into a single casting.
Small-module gears, sprockets, couplings and gearboxes. Carbon steel / cast steel grades, with tooth profiles and fit faces finish-machined on CNC.
Brackets, pump bodies, hub seats and chassis attachments, supplying the wide part range demanded by the service and aftermarket.
Junction boxes, instrument cases and sensor housings. Thin-wall parts are annealed to relieve stress and then pickled; hole positions and sealing faces are machined in one setup.
Rocker blocks, cam housings, guides and fixtures. The many specifications suit multi-cavity wax tree assembly under the silica sol process, organised as volume production.
Wear-resistant consumables such as liners, bushings, guide plates and hammers, in carbon or cast steel grades to your heat treatment requirements.
Handrail fittings, decorative parts, clamps and equipment parts in 201 / 202 / 304, produced on multi-cavity wax trees.
Photo slots are reserved in two formats: 21:9 for plant exterior banners and 4:3 for close-ups of individual process stations. All images are taken on site with lighting and colour correction only.
The sign wall carries the company name in Chinese and English, with the gatehouse and retractable gate to the right and the No. 55 Jingyuan Road plate.
The long facade of the casting workshop with the paved front yard, used for material handling and parking.
Corner of the main workshop with the company sign on the gable wall and the loading bay doors below.
A parking canopy and green belt run along one side of the plant road, which leads to the casting workshop.
An Industrial Park road outside the plant, with a pedestrian crossing at the junction and solar street lights and a speed limit sign along the roadside.
Both the mid-temperature and low-temperature wax lines are injected in metal dies: body, gate and tree-assembly bosses form in a single shot, and surface and dimensions are checked once the pattern is removed from the die.
Each tree is dipped into the silica sol slurry and lifted to drain, then stuccoed and dried layer by layer; the face-coat slurry governs shell surface quality and dimensional accuracy.
The charge is weighed out by grade and melted in 150kg and 250kg medium-frequency induction furnaces; tapping and pouring follow only after melt-side spectrometer analysis confirms each heat.
Once the shells are loaded, steam removes the wax patterns and the recovered wax is reused; the mid-temperature and low-temperature wax injection lines are each served by one dewaxing autoclave. After dewaxing, the shells are sintered in high-temperature burnout before pouring.
After shell removal the tree is cut at the abrasive wheel to remove the gate, and the castings are separated from the sprue before grinding and dressing.
With the gates removed, castings are ground at the wheel to clear flash and gate remnants, bringing the surfaces to an inspection-ready condition.
Annealing is applied to the grade and the drawing requirement, relieving casting stress and adjusting hardness and structure. The furnace has a chain-driven lifting door and a firebrick lined chamber.
Pickling removes oxide scale and residual sand; stainless parts are passivated in the same cycle, then moved to inspection.
The spectrometer room houses a benchtop optical emission spectrometer with high-purity argon. The chemistry of every heat is confirmed before pouring, and the figures on the material certificates supplied with the goods come from these heat-by-heat records.
On-site visits require two days' notice so the relevant line and inspection records can be prepared; drawings, physical parts and batch numbers can be checked together during the audit.
Book a plant visit
The plant is located in Shangjing Industrial Zone, Datian County, Sanming, Fujian. Shell making runs on two wax injection lines — mid-temperature wax and low-temperature wax — chosen by part structure and surface requirement. Melting uses three induction furnaces of 150 kg and 250 kg, with a spectrometer confirming chemistry before pouring; shell removal, grinding, annealing, pickling and inspection of the castings are all completed on site. Machining covers 16 machine tools, up to 5-axis, scheduled and delivered together with the casting operations, so orders of mixed variants and non-standard structures gain more consistent process control and more reliable delivery dates.
Operating under ISO 9001. From melt-side chemistry and critical dimensions to final appearance, inspection records are retained by batch, so any abnormality can be traced to the specific operation.
ISO 9001 quality · ISO 14001 environmental · ISO 45001 occupational health and safety
The certificate numbers, issuing body and certified scopes are listed on the Quality Assurance page
The quality manual and procedure documents are available on request
Charged to grade into the medium-frequency furnace
Melt-side spectrometric analysis confirms chemistry
Metal that fails is not tapped and not poured
Critical dimensions checked to the drawing
Surfaces visually inspected piece by piece
Rejects removed before packing
Regular exports to Taiwan · Japan · Europe and the US
Wooden case / pallet packaging with moisture protection
Packing lists and customs documentation supported
304 / 316 are grades for wrought stainless steel (plate, bar); CF8 / CF8M are grades for stainless steel castings, and their chemistry requirements are not identical. A casting drawn as 304 should in fact be melted to CF8 under GB/T 2100 or ASTM A351. For export orders we recommend noting both the casting grade and the governing standard on the drawing, so that confirmation work is not repeated at production stage.
With the 5-axis machining centre in service, castings with inclined hole patterns, curved surfaces and multi-face angular features can be finish-machined in one setup. For customers the direct effect is better delivery control, single dimensional responsibility, and lower tooling and fixture cost apportionment.
For custom parts, die and fixture apportionment usually weighs more on unit cost. Uniform wall thickness reduces feeding and grinding hours, consistent radii and wall sections make shell building easier, and leaving non-fit faces as-cast removes a finishing operation. These three points usually control unit cost materially. One adjustment at the drawing stage often saves a whole round of quotation exchange.
Please provide 2D / 3D drawings with material and quantity requirements. Our process engineers will first complete a round of design-for-manufacturing review of the casting, pointing out where cost can come down while castability is preserved. This step is free of charge and creates no order obligation.
