The short answer The SOMI Partner Network is a vetted group of specialised manufacturing factories in China, coordinated through one point of contact. Buyers get CNC machining, sheet metal fabrication, metal stamping, die casting, injection molding and 3D printing from one programme, with one engineering review, one quality route and one quotation, instead of managing a separate supplier for eve...

The short answer Nothing, in either direction. A manufacturing partner pays no joining fee, no listing fee and no annual subscription, and a buyer pays nothing to use the network - only for the parts actually ordered. What does cost money is the work: samples, tooling, third-party testing, freight, and any audit you ask us to run. What free to join covers, and what it does not Free means acces...

The short answer Two tracks. A buyer joins in one step: send a drawing and the quotation workflow starts, within 24 to 48 hours. A factory joins through qualification - document review, an audit, then sample validation - which takes about two to four weeks for the review and audit and six to fourteen weeks end to end when custom tooling is involved. Two tracks, two timelines One question decid...

The short answer For a buyer the benefit is subtraction: one engineering review, one quotation, one inspection standard, one invoice and one point of accountability across six processes, instead of five separate vendor relationships. For a factory the benefit is inbound work with no listing fee. The hidden surcharge of fragmented sourcing is around 20 percent of the quoted base price. The same...

The short answer Both sinter nylon powder without supports. MJF fuses a whole layer with an infrared lamp and printed agents, SLS traces it with a laser. That makes MJF faster in batches, isotropic to 85 to 90 percent of XY strength, accurate to ±0.2 mm and smoother; SLS offers a wider material range and larger build envelopes. Same physics, different heat source Both processes are powder bed ...

The short answer Every process needs its own mandatory step: support removal on FDM and SLA, powder removal on SLS and MJF, solvent wash and UV cure on resin. Beyond that, bead blasting, vapour smoothing, dyeing, epoxy sealing, annealing, inserts, machining and plating are chosen to match the part's job. Two buckets: mandatory and chosen Post-processing is quoted badly because it is quoted as ...

The short answer A two-plate mould opens at one parting line, gates at the edge and ejects the part with its runner. A three-plate mould adds a floating runner plate and a second parting line, so a pin-point gate can sit anywhere on the face and the runner drops away unaided, for 15 to 40 percent more tool cost. One plate changes everything The two-plate tool is the default because it is the s...

The short answer Most moulded parts land between 1.5 and 3.0 mm: ABS 1.5 to 3.5 mm, PC 1.5 to 3.0, 30 percent glass-filled PA66 1.2 to 3.0. Keep the wall uniform, taper any change at 3:1, and hold ribs at 40 to 60 percent of the wall. Thin walls fail on flow length, thick ones on sinks. Why the wall is the first number you fix Wall thickness sets three things at once, and only one of them is s...

The short answer Most moulded walls need 1 to 2 degrees of draft per side, ribs and bosses 0.5 to 1 degree. Add 1 to 1.5 degrees for every 0.025 mm of texture depth, which takes a typical 0.06 to 0.08 mm grain to 3 to 5 degrees. Core-side features need more than cavity-side ones. What draft actually does during ejection A cooling part shrinks. On the male side of the tool, the core, it shrinks...

The short answer Choose die casting when the housing must carry load, spread heat, block electromagnetic interference or survive fire. Choose injection moulding when it must insulate, stay light and reach a low piece price. Tooling runs 15,000 to 60,000 dollars against 3,000 to 25,000, so volume decides the rest. Start with the material, not the process Die casting and injection moulding look ...

The short answer Porosity, cold shuts, flash, shrinkage, hot cracks and die soldering cause most die casting rejects. Start with the void shape: round voids are gas from venting and shot profile, jagged voids are shrinkage from feeding and wall design. Cut a section before changing any parameter. The defect map Die casting has a short list of failure modes and a long list of causes, and the us...

The short answer Standard EN 755-9 holds plus or minus 0.15 mm on a 3 mm dimension and 0.25 mm across a hollow, opening to 0.5 mm at 90 to 120 mm. Minimum wall is about 0.8 mm in 6063 and roughly 25 percent thicker in 6061; anything tighter than the standard needs secondary machining. Two standards, two price levels Aluminium extrusion is bought against one of two European tolerance systems, a...

The short answer Extrusion wins above roughly 500 to 1,500 parts when the cross-section is constant: a die costs 1,500 to 10,000 dollars, 95 percent of the bought metal ends up in the part and as-pressed tolerance is around 0.2 mm. Below that volume, or where the geometry changes along the length, machine it from stock. The two processes answer different questions Extrusion is a shaping proces...

The short answer Choose 6063 when the profile is visible, thin-walled or complex, because it extrudes at 50 to 60 feet per minute and anodises evenly. Choose 6061 when the section must carry load: at T6 it reaches 290 to 310 MPa against 186 to 240 MPa for 6063, for about 10 to 15 percent more on the metal. One alloying element explains most of the difference Both alloys are Al-Mg-Si from the 6...

The short answer Burr height is set by die clearance first, then by punch sharpness. Hold clearance at 4 to 8 percent of thickness for carbon steel, specify a maximum burr height per edge, and treat rising burr as the trigger to regrind: a die that made 0.03 mm burrs can reach 0.15 mm after 50,000 hits. What a burr actually is Every sheared edge has up to four zones, and the burr is the last o...

The short answer Multiply the total cut perimeter in millimetres by the sheet thickness and by the material's shear strength in kilograms per square millimetre, then divide by 1,000 for metric tons. Add 20 to 30 percent for tool wear, then check the press can deliver that force near bottom dead centre. The formula, term by term Every cutting operation in a press, whether it is blanking, pierci...

The short answer Blanking cuts a shape with 5 to 10 percent clearance per side, leaving rollover, a 30 to 50 percent shear band, a torn fracture zone and a 0.1 to 0.3 mm burr. Fine blanking clamps the strip, cuts at 0.5 to 1 percent clearance and yields an 85 to 100 percent sheared edge. What each process does to the edge Both processes use a punch and a die, and both produce a part in a singl...

The short answer Start with thickness: it sets every other limit. Keep holes at least one thickness across and 2.5 thicknesses plus the bend radius away from a bend line, keep the inside bend radius at one thickness for mild steel, and tolerance to ISO 2768-m except where a feature actually mates. That removes most avoidable cost before a quote is issued. Thickness first, because it sets every...

The short answer For bare steel outdoors, hot-dip galvanizing lasts longest: an 85 micron coating gives roughly 20 to 40 years in a C4 coastal or industrial site, and it keeps protecting scratched edges. Where colour is needed, powder over galvanizing adds a second barrier; 316L stainless needs no coating in marine air. Why there is no single best finish Corrosion is a rate, not a property of ...

The short answer A bend relief is a small notch cut at the end of a bend line, where the bend meets an edge or another flange. Without it the material has nowhere to flow, so it tears or bulges. Cut it at least one material thickness wide and as deep as the bend radius plus one thickness. Why a bend with no relief tears When sheet metal is formed, the outside of the bend stretches and the insi...

The short answer Plan the sequence as rough machine, heat treat, finish machine. Roughing removes bulk while the metal is soft, the treatment releases stress and moves the part, and finishing cuts the movement away. Finish before hardening and you inherit distortion: a quenched 4140 plate can move 0.1 to 0.3 mm over 300 mm. The default route: rough, treat, finish Heat treatment is a stage insi...

The short answer Drilling makes the hole, boring corrects its axis and size, and reaming finishes a drilled hole to a precise diameter. Expect IT12 to IT14 from drilling, IT7 to IT9 from boring, and IT6 to IT8 from reaming, with surface finish improving from Ra 12.5 down to 0.4 micrometres. Three jobs, three tools The three operations are separated by what each one is allowed to change. A twis...

The short answer Cut copper with a sharp, high-positive-rake tool, a feed and depth heavy enough to stay under the work-hardened skin, and flooded coolant. Never let the tool rub: a minimum depth of about 0.13 mm, feeds of 0.03 to 0.05 mm per tooth and 150 to 400 m/min keep the cut shearing cleanly. Why copper hardens under the tool Work hardening, also called strain hardening, happens when th...

The short answer A 5-axis machine moves the tool on three linear and two rotary axes, so it can cut five faces of a part in one setup. It beats 3-axis when the part needs three or more setups, tolerances of ±0.01 mm across different faces, or compound-angle geometry. What the two extra axes actually change A 3-axis vertical machining centre moves the tool along X, Y and Z, and the part sits st...

The short answer A laser marks metal in one of four ways: annealing, which darkens stainless without removing metal; white marking on anodised aluminium and dark coatings; ablation, which burns away paint or powder to reveal the metal; and deep engraving, a fibre-laser recess of 0.05 to 0.5 millimetres. Bare stainless and anodised aluminium survive best. Two lasers, two jobs The first decision...

The short answer Specify the process by a named standard, give a thickness range rather than one number, state how it is measured, list the surfaces that must stay bare, and say whether dimensions are met before or after finishing. A note that says copper plate 10 microns but names no standard, method or masking will be quoted differently by every shop. Why a thickness note fails Most surface ...

The short answer Bead blasting fires fine glass or ceramic beads at the surface to leave a uniform, non-directional matte finish at roughly 1.0 to 3.2 micrometres Ra. Brushing drags an abrasive belt or wheel in one direction to leave a directional linear grain at roughly 0.4 to 1.2 micrometres Ra. Blasting hides fingerprints and takes paint; brushing gives the satin look. Two families of mecha...

The short answer Passivation is a chemical bath, citric or nitric acid, that dissolves free iron left on stainless steel by machining, forming and welding, so the natural chromium oxide layer can re-form. It adds no coating and changes no dimension. It is specified per ASTM A967 and confirmed by a copper sulfate, humidity or salt-spray test. Why stainless steel still rusts Stainless steel resi...

The short answer Powder coating is the default finish for metal. A dry powder is sprayed electrostatically and baked at 180 to 200 degrees Celsius into a 60 to 120 micron film that resists 500 to 2,000 hours of salt spray and releases no solvent. Choose wet paint for a custom colour, a non-conductive part, or field touch-up. Two processes, one decision Both finishes protect metal, and the gap ...

The short answer Phosphating converts a steel surface into a crystalline phosphate layer in a dilute phosphoric acid bath. Zinc phosphate at 1 to 7 grams per square metre is the paint primer; manganese phosphate at 5 to 30 grams is a wear and oil-retention layer for gears and shafts; iron phosphate at 0.2 to 1 gram is a thin adhesion base. What phosphating actually is Phosphating is a chemical...

The short answer Electrophoretic coating, usually called e-coating, immerses the part in a water-borne paint bath and uses a few hundred volts to deposit resin on every wetted surface. The film self-limits at 15 to 35 microns because the coating insulates the part as it builds. That even build reaches internal cavities and edges that spray and powder coating miss. How electrophoretic depositio...

The short answer Electrolytic nickel uses an electric current, so it plates thickest on edges and thinnest in recesses and cannot reach inside blind holes. Electroless nickel uses a chemical reducing agent instead, so the deposit is uniform to about plus or minus 2 microns on every wetted surface, including internal bores, and it is a nickel-phosphorus alloy with better corrosion resistance. T...

The short answer Type II is the corrosion and cosmetic finish; Type III, hard anodizing, is the wear finish. Type II builds 5 to 25 microns and dyes in any colour. Type III runs a chilled bath near 0 to 5 degrees Celsius, builds 25 to 125 microns, reaches 400 to 500 HV and is realistically only black or grey. The process difference in one paragraph Both types are sulfuric acid anodizing, and b...

The short answer Anodizing is an electrochemical conversion that grows an aluminium oxide layer out of the aluminium itself. The part is the anode in a sulphuric acid bath, and the oxide grows roughly half into the metal and half out of it. Type II builds 5 to 25 microns; Type III builds 25 to 125 and hardens to 400 to 500 HV. Why anodizing is a conversion, not a coating Anodizing is often des...

The short answer Design for extrusion means one constant cross-section, uniform walls and generous radii. Keep walls at 1.0 to 3.0 mm with adjacent walls within 2 to 1, use R 0.5 mm minimum at internal corners and R 0.2 mm externally, keep the section symmetrical, and move every hole, thread and cross-wise feature to secondary CNC machining. What the process actually constrains Extrusion pushe...

The short answer Aluminium extrusion gives a structural frame a custom cross-section at a die cost of 500 to 3,000 dollars, a third of the weight of steel at comparable section strength, natural corrosion resistance, thermal conductivity near 200 watts per metre-kelvin, and material use above 95 percent. For long linear parts it is usually the cheapest route. Why a constant section is an advan...

The short answer Custom stamping suits almost anything that can be cut or formed from flat sheet: automotive brackets, electrical terminals, EMI shield cans, washers and shims, heat-sink fins, appliance panels. The shared conditions are a sheet form, a thickness under about 6 mm, a simple 2D or formed shape, and volume above roughly 10,000 parts a year. The one condition every stamped part sha...

The short answer Stamping forms parts from sheet in a die at 30 to 1,500 strokes a minute; CNC machining cuts them from solid at 5 to 60 minutes a part. Stamping carries a die cost of 3,000 to 30,000 dollars and wins above roughly 5,000 to 10,000 parts a year; CNC carries almost no tooling and wins below that. Where the two cost structures come from The two processes are not variations on a th...

The short answer Finishing adds 2 to 50 percent to the as-machined price. Bead blasting is 2 to 5 percent, Type II anodizing 5 to 10, powder coating 8 to 15, and electropolishing or hard anodizing 15 to 30. A batch minimum dominates small orders: a 150 dollar tank charge is 15 dollars a part at ten pieces and 0.30 at five hundred. Two different numbers, and they diverge Every finishing quote c...

The short answer CNC machined parts can be finished in about a dozen ways, and the substrate narrows the list first. Aluminium takes anodizing in Type II or Type III; steel and stainless take plating, passivation or electropolishing; plastics take bead blasting, vapour smoothing or paint. The function you need, not the look, decides which one. What a finish actually does to a CNC part Every fi...