A buyer in Yokohama, Japan working on semiconductor equipment has a thin stainless liner whose slot edges must be blended without distortion or lodged media. SurfacePolish supplies finishing machines, media and compounds across borders and runs a free sample trial, in which the liner is shipped to Xiamen and returned with an observed condition plus a proposed media, compound and cycle direction that the buyer can assess against its own requirements. This brief is written for a buyer in Yokohama working on semiconductor equipment; it describes equipment, media and a scoped sample review, not a local polishing service.
Is edge rounding tolerable on a knife edge or bore lip, and what maximum radius belongs on the drawing?
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?
Batch composition is a process variable, not a logistics detail. Mixing a 4 kg chamber lid with a handful of small stainless fittings changes media circulation, the cycle energy per part and the contact pattern between parts. Delicate electrode plates and thin-wall liners can be dented by heavier neighbours, and aluminium fines released in one batch can transfer onto stainless parts in the next unless the charge and the machine are cleaned between material families. Decide the part mix, the maximum mass per batch and whether fragile parts need racking or compartmentalisation. Decide also how batches are identified, with a traveller that carries material, media charge, compound, cycle time and operator, so a finishing result can be traced back to the settings that produced it. Batch identity is the basis for any later comparison.
A vibratory bowl is the general-purpose starting point for chamber bodies, plates and housings that fit comfortably and can tumble without racking. Media circulates in a toroidal path and reaches external faces, edges and open pockets at moderate energy, and the open bowl allows an operator to pull a part mid-cycle for a look, which matters when a feature is sensitive. Part-on-part contact is continuous, so thin plates and finished mating faces need separation or protection within the charge. Where a heavy machining burr has to come off before refinement, a grinding finishing machine with higher removal energy can take the bulk of it, but it cuts edges faster as well and needs a tighter geometry assessment. A bowl will not reach deep internal passages on its own; those depend on media size, compound flow and how the part sits in the charge.
| Machine route | Where it fits | What it will not do |
|---|---|---|
| Dry polishing machine and dryer | Removing residual moisture after a wet cycle and reducing water spotting on aluminium and stainless surfaces | A finishing step only; a dry part can still carry compound film, fines and media dust, so it is not a cleanliness release |
| 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 |
| Tub vibrator | Long gas rails, tubular manifolds, weldments and linear electrode assemblies that cannot rotate in a bowl | Lower energy per unit area so heavy burrs take longer, and large tubs need floor space and a suitable part support method |
| Disc finishing machine | Fast, high-energy edge breaking and surface refinement on small robust parts and uniform batches of fittings | High impingement and edge-loss risk on thin or soft parts, and geometry must suit the disc working gap |
Compound choice controls residue as much as it controls cutting. Alkaline and neutral families are common for general deburring and cleaning, acidic families may be used where a descale or brightening effect is wanted, and silicate-bearing products can leave a tenacious film that is difficult to remove from a sealing face or a gas passage. For aluminium, a compound with an effective corrosion inhibitor is usually necessary to avoid darkening and surface attack during and after the cycle. Concentration, flow rate and temperature all shift the result, so dosing should be metered rather than guessed. Water quality matters too: hardness, chloride content and suspended solids affect foaming, rinsing and the residue left behind. The question to put to a supplier is what the compound leaves on the part, how it is removed, and what evidence a buyer can collect to confirm removal.
| Media | Best fit | Watch out for |
|---|---|---|
| Plastic triangles and pyramids in a soft to medium grade | Deburring aluminium and other soft alloys where surface marking and edge rounding must be kept to a minimum | Slow cut rate, media deforms and wears, and a worn charge behaves noticeably differently from a fresh one |
| 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 |
| Steel media, including balls and shaped pins | Bright finishing and edge blending on stainless components where appearance and a burnished surface matter | Transfers iron to aluminium and carbon steel, needs a corrosion-inhibiting compound, and must be separated magnetically or by screen at unload |
| 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 |
Cross-contamination and staining are quiet failures. Aluminium worked in a charge previously used on stainless can leave a grey smear; stainless run with steel media, or in a machine that has held carbon steel, can show rust spots that appear days later; hard water and slow drying leave mineral spotting; and a compound that is too aggressive darkens aluminium. Dimensional drift is the other quiet failure, where thin plates, long tubes and unsupported walls relax or distort under tumbling loads, so a part that passed the edge check fails a flatness or position check afterwards. Both categories are caught by discipline rather than by looking harder at the finish: segregate material families and dedicate or purge media, control rinse water and drying, measure defined dimensions and flatness at the same points before and after, and keep that data with the batch record.
| Failure mode | Likely cause | How to catch it |
|---|---|---|
| Compound film or tenacious residue left on a sealing face | A film-forming or silicate-bearing compound, insufficient rinse volume, or drying the part before it is genuinely clean | Magnify the sealing land and wipe a defined area with solvent, comparing the wipe against a clean reference; confirm with the buyer's own cleanliness method |
| Uneven finish with unrefined pockets, corners or the shielded side of a flange | Media cannot reach the feature at the chosen size or orientation, charge flow is blocked, or the part was not repositioned during the cycle | Inspect at defined locations rather than judging the whole part, photograph the same feature before and after, and measure roughness only at the surfaces the drawing controls |
| Thin plate or liner distorted, bowed or dimensionally drifted after the cycle | Tumbling load on an unsupported thin section, part-on-part contact, or heat and pressure from a high-energy route | Measure flatness, wall thickness and critical dimensions at the same marked points as the pre-process baseline, using a CMM or surface plate and gauge |
| Bright impact marks, dents or flattened corners from part-on-part contact | Dense charge, high load ratio, thin or light parts left loose among heavy neighbours, or a cycle run longer than the edge condition required | Look for repeating mark patterns on exposed faces and edges, compare an unsupported part with a racked or compartmentalised one, and review the batch mix and load recorded for the lot |
Yokohama combines a waterfront heavy-industry zone with a large base of small and medium manufacturers. The city lists eight separate industrial accumulation areas, including the Keihin coastal zone, which it calls a major industrial region representing the Greater Tokyo area, and LINKAI Yokohama Kanazawa, where more than 1,000 companies and offices are located. The city's investment material states that Yokohama has clusters of automotive and other manufacturing, IT and life-science industries, together with R&D bases of global companies, and that it ranks first among Japan's designated cities for both the number of academic and R&D institutions and the number of engineers and researchers. The port's designated zones are predominantly industrial: of a 2,936.8 ha waterfront district, 1,712.1 ha is classified as an industrial port zone.
The nearest part of that base to this brief is automotive: Yokohama City's business-environment page states that the city has clusters of the automotive industry and other manufacturing, IT and life-science industries.
Yokohama's manufacturing base mixes automotive and general machinery production, in which deburring and edge quality affect fit, fatigue life and coating adhesion, with life-science and R&D activity, where cleanliness and documented surface condition matter. A dense supplier base across eight accumulation areas means an incoming parts specification is likely to pass through several subcontractors, so a shared, measurable finish requirement reduces rework at hand-offs.
A Yokohama buyer sourcing from an eight-area supplier base should fix one measurable edge and surface specification for the whole chain and agree who inspects it, rather than letting each subcontractor apply its own visual standard.
Freight context: Port of Yokohama (横浜港) — piers including Minami-Honmoku, Honmoku, Daikoku and Osanbashi, Haneda Airport, about 24 minutes from Yokohama Station by the city's own access description. The Port of Yokohama has a 7,218.3 ha port area and a 2,936.8 ha waterfront district, of which 1,712.1 ha is an industrial port zone, so both break-bulk and container movements of machinery sit alongside industrial waterfront users. The city publishes the Yokohama Port Statistics Yearbook and fast-report series for throughput data used in freight planning.
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.
The national standards body is the Japanese Industrial Standards Committee (JISC), which states that JIS covers industrial and mineral products, data, services and management systems under the Industrial Standardization Act. Its technical divisions include mechanical engineering, ferrous materials and metallurgy, nonferrous materials and metallurgy, ceramics, medical equipment and safety appliances, and aircraft and aviation, which are the divisions a finishing or deburring requirement is normally read against. Product certification runs through the JIS Mark Certification Scheme, operated by accredited certification bodies compliant with ISO/IEC 17065; as of March 2019 there were 24 JIS-accredited bodies, three of them outside Japan, with about 8,700 certifications issued, and the scheme explicitly covers foreign manufacturers, processors and exporters.
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.
Functional checks catch the failures that visual inspection and roughness measurement miss. On a vacuum part that means the buyer's own leak test on the assembled component, which is the only way to see a seal land that has been rounded or a residue film that opens a virtual leak path. On a gas line it means a flow check against a reference part, since an internal burr or a lodged medium changes conductance. Dimensional verification belongs on a CMM or with hand gauges at the features that can move: slot widths, bore diameters, flange flatness, position of dowel holes and wall thickness on thin parts. Thread gauges confirm that a tapped hole was not rounded out by edge finishing. These checks are performed by the buyer's quality function against the buyer's limits; a finishing report is supporting evidence, not a qualification.
Send parts that represent the real range, not a single convenient sample. The set should include the part with the tightest internal passage, the thinnest unsupported section, the surface that must not be touched, and at least one part in the true as-received condition with its normal burr and soil. Add a coupon of the same material, ideally with a known starting roughness, so a measurement can be compared before and after. Supply a marked-up drawing identifying critical surfaces, edge limits and any cleanliness requirement, plus a short statement of what the part does in service. Quantity matters: several pieces allow a stop-and-look at more than one cycle time. Pack them so they arrive undamaged, label each one, and state the material and heat treatment, since an unlabelled mixed lot cannot be assessed.
Size the medium well below the smallest opening the charge could enter, and treat every passage as a retrieval point rather than assuming it stays clear. Map the tightest hole, slot or cross-drilling first, then choose a size class against that geometry instead of an average part. Add a defined check such as a borescope at an agreed angle, a pin gauge on holes, and a rinse collected through a filter. For Japan buyers preparing a trial, send the part with the smallest passage so the media choice is tested on the real feature. SurfacePolish reports what was observed on tested parts; the cleanliness release remains the buyer's decision.
A pump housing is usually assessed on external edges, bore condition and appearance, and a slightly rounded edge is often acceptable. A chamber component is assessed on small functional surfaces: a seal land that must not round, a gas passage that must stay clear, a locating bore that sets position. That shifts the whole process toward smaller media, gentler energy, more masking and fixturing, and a defined cleanliness step. It also shifts acceptance from a visual judgement to measurements at named features. If a shop quotes both parts the same way, the finishing route is probably being chosen by part size rather than by what the surfaces actually do.
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.
Use Yokohama, 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.
Yokohama buyers reference JIS, maintained by the Japanese Industrial Standards Committee, with the mechanical engineering and ferrous materials divisions covering machined metal parts, and the JIS Mark scheme available for third-party product certification, including to foreign exporters. For finishing, the customer's drawing and incoming-inspection sheet define burr, edge and roughness acceptance.
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 Yokohama.
The buyer needs the slot edges blended and the surface refined while keeping the liner flat and free of trapped media.
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-0835; 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-0835 · revised 2026-09-29 · cross-border equipment, media and scoped sample review. City context is sourced and cited above.
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