A buyer in Hiroshima, Japan in energy equipment has an aluminium actuator housing whose thin fin edges and thread entries need deburring without peening the alloy, rounding the O-ring bore lip or bending the fins. SurfacePolish supplies finishing machines, media and compounds across borders and runs a free sample trial, returning the parts from Xiamen with an observation record and a proposed media, compound and cycle direction. This brief is written for a buyer in Hiroshima working on energy equipment; it describes equipment, media and a scoped sample review, not a local polishing service.
What is the smallest internal passage, cross-drilling or tapped hole the charge must never plug, and how would a lodged medium be found and removed?
What must the part be clean of, and what method and limit does the buyer use to verify cleanliness before assembly, welding, coating or a leak test?
Is deburring done before or after heat treatment, and in what metallurgical and surface condition does the part arrive at the finishing step?
Name the burr before choosing a cut energy. A Poisson burr pushed sideways by tool pressure sits along a machined edge; a rollover caps the edge where the tool exits; a tear leaves a ragged fragment on a ductile material; and a secondary burr forms on the far side of a drilled or tapped feature. They do not respond to the same charge. A thin rollover on stainless can be blended away by a light refinement pass, while a thick tear on a casting may need a heavier cutting stage before any edge blending begins. What matters is the burr root, the material still attached below the visible lip. An edge that looks clean can still carry a root that later releases a particle into a hydraulic or gas circuit. Record how that judgement was made.
Compound delivered at the wrong concentration or flow makes the same media behave like a different charge. Too little and the abrasive cut becomes dry and marking increases; too much and cutting slows while foam and carry-over rise. Flow rate matters as much as dose, because it is the flow that carries fines away from the part and keeps the working zone consistent across a long cycle. Water quality belongs in the same discussion: hardness, pH and dissolved solids in the make-up water shift the compound's behaviour, and a plant that changes its water source can change its results without touching a machine setting. Where the fluid is recirculated, filtration and turnover decide how much swarf and broken media stay in suspension and how often the bath is dumped.

| Media | Best fit | Watch out for |
|---|---|---|
| Magnetic pin or needle charge | Reaching small internal intersections, radial holes and thread entries on small precision parts such as spools, sleeves and drilled fittings | Limited by part size and shape, pins must be retrieved and inspected for breakage, and the result depends heavily on fixture and field design |
| Heavy-cut ceramic, angle-cut triangles in a coarse size class | Removing a substantial or thick burr root from open external edges, flange corners, cast bosses and large tapped entries on steel and stainless parts | Cuts controlled edges and gasket lands as readily as burrs, leaves a coarse surface, and lodges in slots whose width approaches the media section |
| Fine ceramic spheres or small porcelain shapes in a light size class | Refinement and edge blending after a cutting stage, and light deburring of small fittings, thread entries and tighter external geometry | Small sizes enter and retain in fine passages and cross-drillings, and the charge changes size and cut rate as it wears |
| Plastic media triangles and pyramids in a soft to medium grade | Deburring aluminium, brass and other soft or thin-walled parts where surface marking and edge rounding must stay minimal | Slow cut rate, media deforms and wears out of shape, and a worn charge behaves noticeably differently from a fresh one |
Internal intersections are a different problem from external surface refinement, and no amount of extra energy in a bowl fixes them. A cross-drilling meeting a main bore creates a burr on the inside wall that external media rarely reaches. Access routes include a small media size class that can enter the passage, magnetic finishing where a pin or needle charge is driven into the feature on small parts, or a targeted mechanical method outside mass finishing. Each has a boundary: a size class small enough to enter a passage is also small enough to lodge in it, magnetic pins are limited by part size and by retrieval, and blind features with no exit cannot be flushed clean. Decide per feature which access route is credible, and how the result will be seen.
| Machine route | Where it fits | What it will not do |
|---|---|---|
| Vibratory finishing machine (bowl) | General deburring and refinement of valve bodies, flange plates, pump components and fittings that fit the bowl and can move freely in the charge | No access to deep internal passages, constant part-on-part contact, and finished faces need separation or fixture protection |
| Magnetic finishing machine | Small precision parts with internal intersections, radial holes and thread entries that a bulk charge cannot reach | Limited by part size and material, pins must be retrieved and checked, and it does not level or refine large flat surfaces |
| Dry polishing machine and dryer | Drying after a wet cycle and dry light polishing or deburring of small parts, including features where residual moisture is a problem | Removes little or no material, needs dust extraction when dry media is used, and does not replace a cutting stage for a substantial burr |
| Disc finishing machine | Fast, high-energy cycles on small to medium robust parts, including batches of fittings and small housings that need a quick cut | High contact pressure rounds edges quickly and can mark or deform thin and soft parts, with results sensitive to load and disc condition |
Contamination in this process is mostly invisible at the machine and is discovered downstream. Three forms matter on energy-equipment parts. Media fragments and abrasive fines can embed in soft surfaces or in a machined groove and later appear as particles in a fluid system. Material carryover happens when carbon steel fines or cast-iron graphite from an earlier batch stay in the charge, the machine, the rinse tank or the drying cloth and transfer to stainless parts. Compound residue and its reaction products can sit in a gasket groove, a thread or a blind hole and interfere with welding, passivation or a coating step. Control is separation and cleaning discipline, verified with a wipe or tape lift, magnification, and a flush residue check.
| Failure mode | Likely cause | How to catch it |
|---|---|---|
| Loss of flatness or a dimensional shift on thin plates, thin walls and long unsupported sections | Part-on-part impacts and fixture pressure in a high-energy route, too high a load ratio, or insufficient support along a slender part | Check flatness on a surface plate or a coordinate measuring machine at marked points before and after finishing, and check the same points across parts from different load positions |
| Burr lip folded flat over the edge with the root still attached | Too light a cut for the burr thickness, a refinement-only pass used as the only stage, or a soft ductile material that rolls instead of fracturing | Draw a probe or lint-free wipe along the edge, examine at magnification under angled light, and take a sectioned or moulded replica sample where the feature is critical |
| Burr still present on an internal cross-drilling intersection after finishing | No credible access route for the charge, a medium too large to enter the passage, or a cycle too short for the intersection to see enough contact | Borescope the intersection at the agreed angle on sample parts, section one representative part to expose the wall, and compare against the recorded as-received condition |
| Media fragments or abrasive fines embedded in a soft surface or machined groove | Impingement from excessive energy or charge mass, fractured media left in the working charge, or cross-contamination from a previous material family | Inspect at magnification under angled light, use a tape lift or solvent wipe on the suspect area, and screen the charge for broken media and accumulated fines |
Hiroshima Prefecture's industrial base is organised around automobiles and their supply chain: the prefecture's industry department describes a Hiroshima automotive industry-academia-government collaboration council founded in 2015 by six organisations with a 2030 vision, together with a car-technology innovation centre that supports automotive suppliers, and a separate division for automotive industry promotion and for advanced manufacturing and new technology development. Aircraft is a second organised cluster: the prefecture's Hiroshima Aircraft Industry Promotion Association (エアクラフトひろしま) builds an aircraft supply chain with more than 150 member companies and organisations, mainly manufacturers in the prefecture, and the prefecture also runs a carbon-neutral manufacturing business programme. Hiroshima Port is designated an international hub port (国際拠点港湾) serving the Hiroshima Bay industrial zone.
The nearest part of that base to this brief is aerospace: The prefecture established the Hiroshima Aircraft Industry Promotion Association (エアクラフトひろしま), and states that more than 150 companies and organisations, mainly manufacturers in the prefecture, take part in building a strong aircraft-related supply chain.
Automotive parts produced around Hiroshima - machined, stamped and cast components - are deburred and edge-conditioned before assembly, painting or inspection, and the prefecture's supplier-development programmes put supplier process capability under review. Aircraft supply-chain work adds documented process control and cleanliness expectations, so surface condition and edge quality have to be repeatable and recordable rather than merely visually acceptable.
A Hiroshima buyer should first settle which customer regime governs the part - automotive drawing tolerances for edge break and burrs, or an aircraft flow-down requiring documented process control and cleanliness - because that determines how much of the finishing process has to be specified, recorded and verified rather than judged by eye.
Freight context: 広島港 (Hiroshima Port), 国際拠点港湾. The prefecture's port authority office states that it manages and promotes the international hub port Hiroshima Port together with the ports in Etajima City, serving the Hiroshima Bay industrial zone; that makes Hiroshima Port the natural route for incoming finishing machines and for outbound sample parts.
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.
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.
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.
An acceptance record is only as strong as the chain behind it. A measured roughness or edge radius means little unless the record links the part to the batch, the batch to the charge, and the charge to the media type, size class, charge age, compound and settings used on that day. Request the settings record with the returned parts, plus the media and compound identification, the cycle count on the charge and the maintenance history. On the measuring side, know the calibration status of the instrument and the uncertainty attached to the value, because a reading quoted to two decimal places on an uncalibrated gauge is not evidence. Decide which records the buyer owns and which are requested from the supplier.
Results from a small trial machine do not transfer linearly to a production machine. A larger bowl, a longer tub or a bigger barrel changes the energy per part, the path a part travels and the ratio of media to part mass. Cycle time is not a simple scale factor: doubling the load does not double the time, and running the same time in a larger machine usually removes more material from the edges than expected. The load ratio, the media-to-part volume, the compound flow per unit of charge and the unloading method all shift. Treat scale-up as its own first-article exercise on the production machine, stepping up in load while checking the same features. A trial result is a direction to test at scale.



Use more than one method, because each misses something. Visual inspection under angled light at magnification catches obvious sharp edges, wire edges and remaining burr fragments. A tactile check with a probe, a fine needle or a lint-free wipe drawn along the edge catches lips that have been folded flat. A radius gauge, optical comparator or moulded replica gives an edge size, and a profilometer or surface roughness tester with a suitable cut-off and traversing direction gives a profile across the edge when the geometry allows it. Microscopy helps on small features and when documenting a dispute. Compare against a master agreed before the batch.
They can be run in the same equipment, but not safely in the same charge without a cleaning discipline. Carbon steel and cast iron leave fines and graphite that transfer to stainless parts, show up as rust staining or embedded particles, and are difficult to see at the machine. The practical approach is a dedicated charge per material family where volume allows, or a purge between families: run the machine with media and clean compound, flush the rinse tank, change or clean the drying medium and cloths, and inspect the media for embedded ferrous fines. Tell the finishing route which families will alternate, because changeover time is a real cost.
Sometimes, and only through a defined access route. A burr on the inside wall of a cross-drilling can be reached by a small media size class that enters the passage, by a magnetic pin charge on parts small enough for that machine, or by a targeted mechanical method rather than bulk mass finishing. What decides it is the smallest opening, whether the passage has an exit, and how the result will be inspected. For a Japan buyer, send the part with its tightest intersection and agree how the internal edge will be borescoped or gauged. SurfacePolish reports observations on the parts tested; the requirement stays the buyer's to define.
Use Hiroshima, 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) administered through the Japanese Industrial Standards Committee (JISC); the official JIS database allows standards to be read but not printed, so buyers normally work from purchased or licensed copies and from the JIS number cited on drawings. Management-system certification to ISO 9001 is commonly required as general industry practice, and aerospace customers flow down their own additional process and documentation requirements.
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 Hiroshima.
The buyer wants the fin edges and thread entries deburred without peening the soft aluminium, rounding the O-ring bore lip or bending the fins.
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-0868; 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-0868 · revised 2026-09-29 · cross-border equipment, media and scoped sample review. City context is sourced and cited above.
Email : info@surface-polish.com