The short answer At room temperature, as-built SLM parts land close to wrought: SLM 316L prints at about 570 MPa tensile against 485 to 515 MPa for annealed wrought bar, and SLM Ti6Al4V reaches about 1,200 MPa against roughly 950 MPa wrought. Yield strength is often higher and elongation lower. Fatigue is the gap: as-built surfaces sit at Ra 6.3 to 12.5 micrometres. The comparison, alloy by al...

The short answer For plastic prototypes, sintered nylon beats everything else: SLS or MJF PA12 prints at roughly 45 to 50 MPa tensile with 15 to 20 percent elongation and near-isotropic strength, while FDM parts carry only 50 to 75 percent of their strength across layers. For metal prototypes, SLM is the strongest route, matching wrought values. The ranking, on one scale Strength is not a prop...

The short answer SLA cures liquid resin with ultraviolet light and holds the finest detail, down to 25 micron layers and Ra 1 to 5 micrometres. SLS sinters nylon powder with no supports, giving the strongest and most near-isotropic parts. FDM extrudes filament and is the cheapest, with 100 to 300 micron layers and visible layer lines. Three processes, three mechanisms The three names are abbre...

The short answer Print when the question is shape, and machine when the question is performance. 3D printing delivers a first article in one to three days for USD 50 to 500, holding about ±0.1 to 0.3 mm. CNC holds ±0.01 to 0.05 mm in production material but takes three to seven days and costs USD 80 to 2,000. The rule: shape versus performance Almost every prototype decision reduces to one que...

The short answer Seven additive families exist, but five carry almost all professional prototype work: material extrusion, vat photopolymerisation, polymer and metal powder bed fusion, and jetting. They differ by how material is deposited, by the accuracy each holds - roughly ±0.05 mm at best, about ±1 mm at worst - and by what the finished part can do. Seven families, five that matter Additiv...

The short answer Zinc wins on strength per unit volume and on thin walls; aluminium wins on strength per kilogram. Zamak 3 reaches 215 to 283 MPa tensile with about 10 percent elongation, against about 320 MPa with 1.5 to 3.5 percent for A380. Zinc is 2.4 times denser, so aluminium wins any weight-driven programme. Strength: the same headline number, two different meanings Zinc and aluminium a...

The short answer Zinc die casting suits small to medium parts that need thin walls, fine detail, tight as-cast tolerance and a platable finish: locks and door hardware, plumbing fittings, electrical connectors, power-tool and appliance parts, and decorative components. It is the wrong choice for large, weight-critical or high-temperature parts. Six product families, and why zinc fits each Zinc...

The short answer Plan on 8 to 12 weeks for new aluminium die casting tooling: about 2 to 3 weeks of die design, 4 to 6 weeks of steel machining and 1 to 2 weeks each of benching and tryout. First production then runs 3 to 4 weeks, and repeat orders 2 to 3 weeks. The project in four milestones, not one number A single lead-time figure is the least useful number a buyer can be given, because the...

The short answer Aluminium die casting suits vehicles and aircraft because one process delivers thin-wall complexity, low mass and a heat path at automotive volume. Density is 2.7 against 7.8 g/cm3 for steel, walls go to 1.5 mm, thermal conductivity is 90 to 120 W per metre-kelvin, and a shot takes 30 to 90 seconds. What a vehicle asks for, and which property answers it A car and an aircraft a...

The short answer At high volume die casting wins on unit price, but only above a crossover that lands somewhere between 500 and 3,500 pieces depending on the die cost. Below it CNC machining is cheaper because there is no tooling to repay. The honest answer is often hybrid: cast the body, machine only the features that carry a dimension. The decision is one division, so run it on your own numb...

The short answer Die casting forces metal into a reusable steel die at 10 to 175 megapascals, making a part every 30 to 120 seconds at ±0.1 to 0.25 mm. Sand casting pours into a disposable sand mould under gravity and holds only ±0.5 to 1.0 mm, so it wins below 5,000 pieces and for ferrous metals. Same idea, opposite economics Both processes pour liquid metal into a cavity, and almost everythi...

The short answer Consistent weld quality comes from process control, not from inspection alone. Write the welding procedure and qualify welders to it, control joint preparation, gap and parameters, then inspect in three phases: before, during and after the arc. Inspect 100 percent visually and add NDT in proportion to what the joint carries. Consistency is a process property, not something you...

The short answer Use TIG for thin, cosmetic work in stainless or aluminium from 0.5 to 3.0 mm, MIG for structural steel from about 1.2 to 6.0 mm, fiber laser for thin enclosures where distortion and finish matter, and resistance spot welding for lap joints in high volume. Thinnest wall and joint type decide, not preference. There is no best process, only a best fit Every welding argument on a ...

The short answer Bend allowance is the arc length of the neutral axis through a bend, so it is the material that bend consumes. On two millimetre mild steel with a two millimetre inside radius, one 90 degree bend takes about 4.3 mm, so add each allowance to the flat legs to size the blank. Bend allowance is the arc length of the neutral axis When sheet metal bends, the outside surface stretche...

The short answer Air bending is the default and covers most custom sheet metal work, holding roughly 0.5 to 1.0 degrees with one tool set. Bottoming and coining tighten that to about 0.1 to 0.5 degrees on angle-specific tooling, roll bending forms large curves, and hemming folds an edge for safety and stiffness. Five techniques cover almost all press-brake work Bending looks like one operation...

The short answer Industrial fiber laser cutting holds about ±0.1 mm on sheet under 3 mm, ±0.15 to 0.2 mm on 3 to 10 mm plate and ±0.3 to 0.5 mm on plate over 10 mm, with repeatability near ±0.05 mm across a run. Kerf is 0.1 to 0.3 mm. Bending and welding then add their own error. Accuracy and repeatability are two different numbers Laser cutting tolerances get misquoted because two different m...

The short answer Industrial fiber laser cutting handles roughly 0.5 to 20 mm across common metals: about 20 mm carbon steel, 15 mm stainless and 12 mm aluminium on a 6 kW machine, rising to 60, 40 and 30 mm at 20 kW. Copper and brass stay under 10 mm. Thickness is set by power, and power alone does not promise a clean cut Every laser cutting capacity table is really two numbers, not one. The f...

The short answer Professional sheet metal fabrication runs six stages: design and flat pattern, material selection, cutting, forming, welding and assembly, then surface finishing and inspection. Cutting and forming set the tolerance, finishing is the largest single cost line at 25 to 40 percent, and the first part carries all the setup. Six stages, and the one number each stage controls The pr...

The short answer Choose sheet metal fabrication when the part is a thin-walled enclosure, panel or bracket between 0.5 and 6 mm and you expect volume: material use of 70 to 85 percent makes it 30 to 60 percent cheaper above roughly 50 units. Choose CNC for solid bodies, tight tolerances and complex 3D features. Geometry decides before cost does The question is not which process is better but w...

The short answer LSR molding supplies medical tubing and seals, baby nipples and pacifiers, kitchenware gaskets, automotive and EV battery seals, wearable and keypad seals, and industrial O-rings. These parts share three traits: thin walls from 0.3 to 3 mm, a service window from -60 to 200 degrees Celsius, and volumes above about 25,000 a year. Six product families, and the trait they share Li...

The short answer LSR brings four things medical and food parts need: it can be supplied with USP Class VI and ISO 10993 test data, it meets FDA 21 CFR 177.2600 and EU 10/2011 food-contact rules, it survives steam, EtO and gamma sterilization, and it works from -60 to 200 degrees Celsius with low compression set. What "medical grade" actually means: standards, not claims The phrase medical grad...

The short answer Pick the overmold for its chemistry, not its colour: ABS, PC, PC-ABS and nylon bond chemically to matched TPE grades at 100 to 300 newtons of peel strength, while PP needs a modified grade and POM, HDPE and PEEK bond only mechanically. Then check melt temperature, hardness and wall thickness. Chemistry decides first: polar bonds, non-polar does not Overmolding works by bonding...

The short answer Overmolding is used for soft-touch grips on tools and appliances, sealed connectors and integrated gaskets, vibration-damping mounts, encapsulated electronics and dual-durometer parts. It replaces a glued or snap-fitted assembly with one bonded component, typically cutting assembly cost by around 30 percent and holding soft layers from 0.8 to 3 mm. Six application families and...

The short answer Two-shot injection molding uses one machine with two injection units and a rotating, indexing or core-back mold. The first shot forms a rigid substrate in cavity A, the mold moves the partly cooled part to cavity B, and the second shot bonds a second colour or a soft elastomer onto it, with no manual handling. What a two-shot machine actually does A two-shot press is not a sta...

The short answer Bi-colour molding pays off for consumer electronics because it replaces two or three secondary operations with one cycle. Soft-touch grips, scratch-proof colour, sealed gaskets and light-guide windows are formed in the mold, typically cutting 15 to 30 percent from unit cost and removing the assembly steps where delamination, misalignment and paint wear begin. Where the value s...

The short answer Insert molding improves strength by locking metal into plastic rather than pressing it in. Molten plastic at 40 to 140 megapascals fills the knurls and undercuts, then shrinks 0.5 to 2 percent as it cools and grips the insert, giving a pull-out force two to four times that of an insert fitted after moulding. The interlock is mechanical, not adhesive An insert designed for mold...

The short answer Insert molding places a metal or plastic insert on a locating pin in the tool and floods molten plastic around it, so the insert becomes part of the moulding. Choose it over post-moulding assembly when the joint must resist repeated torque and vibration, close a leak path, or hold at volumes above about 20,000 parts a year. What insert molding is, step by step Insert molding i...

The short answer Cut injection molding cost by fixing the part design before the tool is cut. Keep walls uniform at 1.5 to 3 mm, pull 1 to 3 degrees of draft, radius every corner at half the wall, and remove undercuts needing side actions. These changes typically cut tooling 20 to 40 percent and cycle time 15 to 25 percent. Where injection molding cost is actually decided Most of the cost of a...

The short answer Above roughly 10,000 parts a year the question stops being about technology and becomes a question about tooling phases. A printed prototype proves shape; an aluminum bridge tool proves the molded part in production resin; a hardened steel tool proves mass production. Each handoff changes shrink, gate position, cooling and tolerance, and each is where launches lose weeks. Why ...

The short answer Minimum order quantity is not a supplier policy, it is an amortization question. A soft aluminum tool costing 1,500 to 5,000 US dollars becomes practical at 50 to 200 parts; a standard P20 steel tool at 8,000 to 18,000 dollars needs 500 to 1,000; a hardened precision tool at 15,000 to 35,000 dollars or more needs 2,000 to 5,000. MOQ is arithmetic, not house rules The tooling h...

The short answer Warping and sink marks are volumetric problems. Amorphous resins like ABS and polycarbonate shrink 0.3 to 0.8 percent; semi-crystalline PP, POM and nylon shrink 1.0 to 3.0 percent and sink and twist more. Uniform walls, ribs at 40 to 60 percent of the wall, cooling balanced within 5 degrees Celsius, and correct hold pressure fix most of it. Two defects, one mechanism A sink ma...

The short answer Unit price is set by five things: resin, machine time, tooling amortization, labor and overhead, and scrap. Material typically runs 30 to 55 percent of part cost and machine time 20 to 35 percent, while tooling amortization starts at dollars per part and falls below ten cents once volume passes 100,000. What actually goes into a quoted unit price A molded part price is not one...

The short answer CNC drilling removes the operator from the cycle. The machine positions each hole to within 0.01 mm, changes tools in under 2.5 seconds and runs drill, countersink and tap in one program. Measured throughput is 80 to 200 holes an hour against 20 to 40 by hand, and positioning scrap falls from 3 to 5 percent to under 0.5 percent. What actually changes when the operator leaves t...

The short answer A CNC drilling service produces through and blind holes, counterbores for socket screws, countersinks for flat-head screws, spotfaces for washers, reamed bores at H7, and tapped threads in UNC, UNF and metric sizes. Twist drills reach 5 to 8 times diameter, reaming lifts the fit to 0.005 to 0.02 mm, and gun drilling reaches 100 to 150 times diameter. Every hole starts as one o...

The short answer A professional CNC milling shop works to ISO 2768-m by default, which is 0.1 mm on a 6 to 30 mm feature and 0.3 mm from 30 to 120 mm. Precision work tightens to 0.025 to 0.05 mm, a controlled shop reaches 0.005 to 0.01 mm on a callout, and surface finish runs from Ra 3.2 to 0.4. The default is a standard, not a number When a drawing does not put a tolerance on a dimension, the...

The short answer Judge a CNC milling supplier on evidence rather than on price: the registered entity and its own machine list, the tightest tolerance it holds every day with a first-article CMM report behind it, the inspection plan, and how it answers DFM questions. Ask for two past lot sizes and run a trial order before a mass-production release. Start with the entity, not the price list The...

The short answer CNC milling holds the workpiece and moves a rotating cutter along a toolpath generated from the CAD model, removing material in thin layers. Three axes cut prismatic faces, pockets and slots; a fourth adds indexing, helical and cylindrical work; five simultaneous axes cut free-form contours and undercuts in one setting. The four steps from model to finished face Milling is sub...

The short answer Five industries carry most precision CNC turning demand: automotive at 27 percent of precision machining revenue, aerospace and defence at 24 percent, medical devices at 18 percent, semiconductors and electronics at 16 percent, and industrial machinery at 15 percent. All five buy a round form that must run true at speed. Where precision turning demand actually sits Turning is ...

The short answer Custom CNC turning holds ±0.01 to 0.05 mm to standard, tightens to 0.002 to 0.005 mm on a precision lathe, and reaches 0.001 to 0.002 mm on a Swiss-type machine. Roundness runs 0.5 to 3 micrometres and surface finish reaches Ra 0.4 micrometres. Geometry, not the machine alone, sets the limit. Three tiers, and what separates them Turning capability is usually quoted as a single...

The short answer The difference is motion. CNC turning spins the workpiece against a stationary single-point tool, so it makes round, axially symmetric parts fast and concentrically. CNC milling holds the part still and rotates a multi-point cutter, so it makes flat faces, pockets and slots. Round part: turn it. Everything else: mill it. One mechanical fact explains the rest Almost every pract...