A buyer in Fukuoka, Japan working on semiconductor equipment has a varied batch of stainless vacuum fittings that need a consistent edge break without media trapped in cross-drilled holes. SurfacePolish supplies finishing machines, media and compounds across borders and runs a free sample trial: a representative batch goes to Xiamen and returns with observed results and a proposed media, compound and cycle direction for the buyer to compare. This brief is written for a buyer in Fukuoka working on semiconductor equipment; it describes equipment, media and a scoped sample review, not a local polishing service.
Can the required finish be reached in one mechanical route, or does the part need a cut stage followed by a refinement stage?
What is the smallest internal passage, slot or hole the charge must not plug, and how will a lodged medium be detected and removed?
Is edge rounding tolerable on a knife edge or bore lip, and what maximum radius belongs on the drawing?
Before discussing media, establish what the burr actually is and where it sits. Milling leaves a rolled edge on a machined flange, turning leaves a feather on a bore lip, and EDM leaves a recast layer that behaves differently under impact media. Note the edge condition on seal lands and knife edges specifically, because those are the features where rounding is least tolerated and where a specification usually names a maximum radius or a required chamfer. Ask which burrs are functional rather than cosmetic: a burr inside a gas passage affects flow and can shed particles, while one on an external bracket face may not matter at all. Equally, record the cleanliness baseline the part arrives with, since oil, coolant and earlier blasting residue will load the compound and influence the outcome of a first cycle.
Plastic media is chosen for aluminium and other soft materials where a ceramic charge would peen, smear or mark the surface. It is lighter, so contact pressure is lower and edges survive longer, at the cost of a slower cut and a longer cycle for the same burr. Shapes range from triangles and cones to cylinders, and the harder, denser grades remove more material than the softer ones. Because plastic media wear and deform, a charge that has run for many hours behaves differently from a fresh one, and part-to-part consistency can drift within a batch if the charge is not monitored. For a chamber component with a sealing face, plastic is often the safer starting point, and the trade-off to be tested is whether the achievable surface and the cycle time are acceptable once the burr is genuinely gone.

| Media | Best fit | Watch out for |
|---|---|---|
| Heavy-cut ceramic, angle-cut triangles in a coarse size class | Removing a substantial machining burr from open external edges and pockets on aluminium and stainless housings before a refinement stage | Cuts edges and corners aggressively, leaves a coarse surface, and lodges in slots whose width approaches the media section |
| Fine ceramic or porcelain spheres in a small size class | Refinement and light edge blending after a cutting stage, and reaching tighter external geometry on chamber bodies and plates | Small sizes enter and retain in gas passages and fine slots; media wear shrinks the charge and changes the finish over its life |
| Dry media such as walnut shell and corn cob | Drying assistance, light surface drying polish and removal of superficial soil after a wet cycle | Does not deburr or refine metal significantly, generates dust, and must not be treated as a cleanliness step |
| Aluminium oxide grinding media in a dense ceramic bond | Where a heavier stock removal or a more consistent cut is needed on robust stainless parts with thick edges | High removal energy rounds functional edges quickly and is a poor match for thin aluminium plates or knife-edge seal lands |
A tub vibrator suits long parts that cannot rotate in a bowl: gas rails, tubular manifolds, long weldments and linear electrode assemblies. The part is immersed or clamped rather than tumbled end over end, so bending risk from a bowl divider is removed, but the energy delivered per unit area is lower and heavy burrs take longer. Disc finishing machines work in the opposite direction: high energy, short cycles, effective on small robust parts and on producing a consistent edge across a batch of similar fittings, with more risk of edge loss and impingement on thin sections. Neither route is automatically gentler or faster on a sealing face. The deciding factors are part length, mass, how the part can be supported, and whether the critical surface can be presented to the media stream at all.
| Machine route | Where it fits | What it will not do |
|---|---|---|
| Centrifugal barrel finishing machine | Small precise parts and short cycles with high contact pressure, such as inserts, small valve bodies and distribution components | Rounds edges and can distort thin unsupported sections quickly; results are sensitive to charge weight, speed and stop time |
| Grinding finishing machine | Taking off a heavy machining burr or a defined stock layer before a refinement pass on robust stainless work | High removal energy cuts functional edges fast and demands a tighter geometry assessment and shorter cycles |
| Vibratory finishing machine (bowl) | General deburring and refinement of chamber bodies, plates and housings that fit and can tumble without racking, with easy mid-cycle inspection | Continuous part-on-part contact and no access to deep internal passages; thin plates and finished mating faces need separation |
| Rotary barrel finishing machine | Gentle deburring of small fragile components and mixed fitting batches with a generous compound flow | Long cycles, no visibility while running, and internal passages can collect media and compound that must be retrieved at unload |
Edge rounding beyond limit shows up first on knife-edge seal faces, sharp bore lips and fine slot edges, where a fractionally generous radius can change how a gasket seats or how a flow path behaves. High-energy routes, long cycles, dense media and coarse ceramic all accelerate it, and aluminium rounds faster than stainless under the same conditions. The damage is easy to miss on a finished part because the edge looks uniform and polished. Checking means measuring a defined edge feature before and after, using an optical comparator, a radius gauge or a moulded replica of the corner, and comparing against the limit the buyer placed on the drawing. Where a knife edge cannot be protected, masking, a fixture that shields the face, or a gentler medium and shorter cycle are the usual mitigations to test.
| Failure mode | Likely cause | How to catch it |
|---|---|---|
| Grey aluminium smear transferred onto stainless parts in a shared batch | Aluminium fines retained in media, compound or the machine after an aluminium lot, with no purge before the stainless lot | Check stainless surfaces under angled light for a dull grey film, review the changeover record, and inspect the charge and machine sump for retained fines |
| Water spotting or mineral residue left after wet processing and drying | Hard or high-chloride rinse water, slow or uneven drying, or parts stacked wet so moisture is trapped in pockets and grooves | Inspect dried parts under angled light for rings and haze, check the rinse water source and drying method, and verify that pockets and grooves drain before the part is packed |
| A ceramic or plastic medium lodged in a blind tapped hole, slot or gas passage | Media size class too close to the opening, a worn charge that has broken down into smaller pieces, or a retention feature that was never mapped | Count the charge in and out where practical, borescope the smallest passages at an agreed angle, pin gauge every hole, and rinse through a filter for a visual residue check |
| Tapped threads rounded, galled or opened out by edge finishing | Media working the thread crest during a long or high-energy cycle, with no plugging or masking on the hole | Run a go and no-go thread gauge on every sampled hole, inspect crest condition at magnification, and confirm that plugs or masks were used and removed |
Fukuoka City is the economic core of Fukuoka Prefecture on Kyushu's north coast, and the prefecture's industrial policy is organised around two formally designated clusters: it has published regional industrial cluster plans for the semiconductor field and the advanced-mobility field under the national Regional Future Strategy, presented as promoting a total of JPY 600 billion of investment, and it maintains an annual map and database of automotive and car-electronics suppliers that listed 1,251 companies across Kyushu in December 2025, 647 of them in Fukuoka Prefecture. The city promotes hydrogen-related industry through its Hydrogen Leader City Project, and states that it opened a hydrogen station producing hydrogen from municipal sewage biogas for fuel-cell vehicles in 2015, which it describes as a world first.
For this brief the relevant part of that base is semiconductor: Fukuoka Prefecture has drawn up a regional industrial cluster plan for the semiconductor field under the national Regional Future Strategy, announced together with a plan for the advanced-mobility field.
Automotive and car-electronics suppliers in the prefecture machine metal parts and housings where burrs and edge condition affect fit, electrical contact and coating adhesion, so deburring and edge control sit on the normal production route rather than in rework. Semiconductor-related equipment work adds a cleanliness requirement, and the city's hydrogen and environmental-equipment activity adds valve, manifold and plate components whose sealing faces depend on surface finish.
For a Fukuoka-area semiconductor-equipment or automotive supplier the first question is which specification governs the feature in question - a JIS or customer-drawing callout for edge condition and surface roughness on a sealing face, an electrical contact or a cosmetic surface - because that decides whether a vibratory or centrifugal barrel process, a disc finishing machine, or a scoped media-and-compound sample trial is the right starting point.
Freight context: 博多港 (Port of Hakata), including the Island City container terminal, 博多港 中央ふ頭 (Chuo Pier). The city's port pages state that Hakata Port is the sea gateway for Kyushu and western Japan and that about 910,000 TEU of international maritime containers were handled in 2025 (Reiwa 7), with Island City and Chuo Pier serving as logistics gateways. Hakata Port is therefore the practical point of entry for incoming finishing machines and for outbound sample parts.
Chinese industrial machinery entering Japan is classified under the Customs Tariff Law, whose harmonised schedule sets the classification and the General Rate; the Temporary Tariff Measures Law sets a Temporary Rate for certain products, and where the WTO rate or an EPA rate for the goods is lower, that lower rate is applied. The applied rate therefore depends on the exact commodity code, and on whether an economic partnership agreement covers the goods and their origin, so a landed-cost figure has to be confirmed against the specific machine before it is quoted. Japan Customs' monthly country table for August 2026 records exports to China of 1,809,133 million yen and imports from China of 2,361,239 million yen, the largest single-country line in the Asian table, with imports from China up 22.5 per cent year on year.
The customs authority is Japan Customs, the Customs and Tariff Bureau of the Ministry of Finance, with regional customs at Tokyo, Yokohama, Nagoya, Osaka and Kobe. Any person importing goods must declare them to the Director-General of Customs and obtain an import permit after examination and payment of customs duty and consumption tax. The declaration is normally filed by the importer or by a customs broker acting as proxy, on a triplicate import (customs duty payment) declaration form (Customs form C-5020) supported by the invoice, the bill of lading or air waybill, a certificate of origin where a WTO rate applies, certificates of origin for preferential rates, packing lists and freight and insurance documents where required, plus any licence or certificate demanded by laws other than the Customs Law. More than 90 per cent of import procedures are computerised. A JIS Mark certificate is a separate, voluntary third-party scheme; foreign exporters are eligible to apply, and certification bodies must comply with ISO/IEC 17065.
SurfacePolish supplies from Xiamen, China. The buyer's own destination rules, conformity marking, tariff classification and documentation responsibilities stay with the buyer; confirm them against the authorities named above before ordering.
Cleanliness acceptance belongs to the buyer, because only the buyer knows what the part will see downstream and which residue matters. A practical specification names the method, the surface or extract volume it applies to, and the limit. Common approaches include a solvent or water wipe over a defined area with a visual or gravimetric assessment, a rinse-and-filter collection on internal passages, magnification or borescope inspection of sealing faces and slot edges, and the buyer's own leak or functional test on the assembled part. State whether inspection happens on the finished part, after the buyer's own cleaning step, or both. SurfacePolish can report what was observed on tested parts and keep them separated and documented, but it cannot certify a cleanliness level or guarantee a particle result.
Compare one variable at a time. If the question is media shape, hold the compound, the cycle time, the machine and the load constant and change only the medium; if the question is cycle time, hold the charge constant and stop at two or three defined intervals. Running two changes at once produces a result that cannot be attributed. Where a trial includes a refinement stage after a cutting stage, evaluate the stages separately, since a final figure can hide a coarse first stage or an unremoved burr. Blind evaluation helps when several people judge appearance: label the returned parts with codes and have the buyer's inspectors score edge condition, coverage and cleanliness without knowing the settings. Keep the parts and the record. A trial showing both routes failing on one controlled feature is as useful as one showing a difference.



Mechanical mass finishing and electropolishing are different processes with different effects, and SurfacePolish does not supply or perform electropolishing. A mechanical route can deburr and refine a surface, and it may reduce the reason to consider an electrochemical step, but it does not reproduce what electropolishing does to a surface. The honest comparison is to define what the gas line actually requires, then test whether a mechanical route can observe those requirements on representative parts. Where an electrochemical finish is mandatory in your specification, that requirement stays with your own supply chain. This page treats electropolishing only as a comparison point and as a reason to evaluate a mechanical alternative.
There is no single best medium, because aluminium is soft and the trade-off is between cut rate and surface damage. Plastic media is often the safer starting point where a sealing face or a thin wall must be preserved, while a fine ceramic can cut faster if edges tolerate more energy. The deciding variables are the smallest opening a medium could enter, the smallest radius that must not be rounded, and the surface condition the buyer needs. Media size class usually matters more than the broad material name. Send a marked-up aluminium part with its tightest passage and one controlled face, and let the trial compare two size classes.
No cleanliness level or cleanroom readiness is certified or guaranteed here. The offer is cross-border supply of finishing machines, media and compounds, plus a sample trial that reports what was observed on the parts tested under the settings used. Cleanroom and process-environment requirements are defined by the buyer and verified by the buyer's own methods, which may include wipes, rinse collection, magnification, leak testing and functional checks. SurfacePolish can keep tested parts separated, documented and returned with a settings record, and that record can support your verification work in Fukuoka, but the acceptance decision and any compliance statement remain with your quality function.
Use Fukuoka, Japan as the destination on the enquiry and state whether the deliverable is equipment, media and compound, a representative sample review or a line concept. A destination does not imply local stock, a local service point or a local delivery time.
Japanese buyers work to JIS (Japanese Industrial Standards), enacted and revised under the Industrial Standardization Act and administered through the Japanese Industrial Standards Committee (JISC) at METI; the JISC site publishes JIS enactments and revisions while allowing JIS documents to be read but not printed. Surface-finish and material requirements are normally cited on drawings as JIS or as customer-specific specifications, and management-system certification to ISO 9001 is commonly requested as general industry practice.
Sources were retrieved on 2026-09-29 and describe the local industrial and trade context only. They do not evidence any SurfacePolish project, shipment, installation or service in Fukuoka.
The buyer wants a repeatable edge break and a uniform finish across a varied fitting batch without media lodging in the cross-drillings.
Send the material, dimensions, approximate weight, batch quantity, the incoming condition and photographs of the difficult features. Mark which features must not be contacted by media and state how the result will be inspected. This form carries source reference PSEO-0875; quote it if you prefer an additional manual reference.
Open the SurfacePolish enquiry form Email a prepared enquiry
No price, lead time, certification or result is promised here. Confirm whether a sample trial is available for the specific part and what the trial can and cannot show.
Page PSEO-0875 · revised 2026-09-29 · cross-border equipment, media and scoped sample review. City context is sourced and cited above.
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