Engineering plastic injection molding materials suitable for mass production of precision plastic structural parts, wear-resistant sliding parts, gears, shaft sleeves, rollers, guide parts, latch parts, mechanical transmission parts, and low-friction functional parts.
Acetal (POM) is a commonly used engineering plastic material, also known as polyoxymethylene or Saigang, which has good dimensional stability, rigidity, wear resistance, low friction, fatigue strength, and machining/injection molding performance. Acetal (POM) commonly used for gears, sliders, shaft sleeves, rollers, guide parts, clips, connectors, mechanical transmission parts, automotive parts, electronic and electrical structural components, and precision plastic functional parts. Compared to Nylon (PA), Acetal (POM) has lower water absorption and better dimensional stability; Compared to ABS, Acetal (POM) is more wear-resistant and better suited for mechanical moving parts; Compared to Polycarbonate (PC), Acetal (POM) offers better low friction and wear resistance, but its impact resistance and transparent appearance are not as good as Polycarbonate (PC).
By focusing on application scenarios, boundaries of advantages, and non-recommended scenarios, it helps sales, customer service, and quoting staff quickly determine whether the material meets current part requirements.
It has good dimensional stability, low water absorption, good wear resistance, low coefficient of friction, good rigidity, good mechanical strength, good fatigue performance, high forming efficiency, suitable for precision assembly, and suitable for replacing some light-load metal moving parts.
Plastic gears, sliders, guide rails, shaft sleeves, bushings, rollers, guide blocks, pads, wear-resistant plates, snap fasteners, connectors, button structural parts, small automotive functional parts, electronic and electrical structural parts, conveyor equipment parts, automation equipment parts, packaging equipment parts, precision plastic structural parts, low-friction moving parts, ordinary mechanical transmission parts.
High-temperature long-term use parts, high-strength load-bearing parts, high-impact structural parts, strong acid and strong alkali environment parts, long-term outdoor exposure parts, high-gloss spray-painted appearance parts, transparent parts, long-term direct contact parts of food, medical implant parts, high conductivity parts, high thermal conductivity parts, large deformation fasteners requiring extremely high toughness, long-term high-load creep structural parts.
The following parameters come from product information and material knowledge fields, used for design review, quotation communication, and preliminary judgment before material selection.
| Material positioning | Engineering plastic injection molding materials suitable for mass production of precision plastic structural parts, wear-resistant sliding parts, gears, shaft sleeves, rollers, guide parts, latch parts, mechanical transmission parts, and low-friction functional parts. |
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| Precision performance | Injection molding Acetal (POM) suitable for mass production of plastic functional parts with good dimensional stability, especially gears, shaft sleeves, sliders, guide parts, and precision assembly structures. Actual accuracy is affected by material shrinkage, wall thickness, gate position, mold temperature, cooling system, product dimensions, structural complexity, and injection molding parameters. Acetal (POM) dimensional stability is generally better than Nylon (PA) and Polypropylene (PP), but large pieces, uneven thicknesses, and elongated pieces may still experience warping and shrinkage deviations. |
| Dimensional tolerances | Injection molding Acetal (POM) standard dimensional tolerances can refer to ±0.05mm-±0.20mm, making small-size, precision and simple structures easier to control; Large parts, thin-walled parts, elongated parts, uneven thickness parts, and multi-rib structures may have deviations of ±0.20mm-±0.60mm or more. This value is a standard reference range and is not an absolute guarantee tolerance for all structures. It is recommended to define tolerances separately for gears, shaft holes, sliding surfaces, latches, positioning holes, and assembly surfaces. |
| Minimum Wall Thickness | Injection molding Acetal (POM) recommends a minimum wall thickness of no less than 0.8mm-1.0mm. Small localized non-stressed areas can be further optimized, but it is not recommended to make large areas that are too thin. Walls that are too thin can easily cause insufficient filling, insufficient strength, or warping; Walls that are too thick are prone to shrinkage, depression, increased cooling time, and internal stress accumulation. Gears, shaft sleeves, screw posts, and load-bearing assembly positions should have wall thickness appropriately increased. |
| Recommended wall thickness | For ordinary Acetal (POM) structural parts, 1.2mm-2.5mm is recommended; for small gears, sliders, buttons, clips, and connectors, 1.0mm-2.0mm is recommended; for shaft sleeves, rollers, guide parts, screw posts, and positions bearing assembly force, 2.0mm-3.5mm is recommended. The wall thickness should be as uniform as possible to avoid local over-thickness that can cause shrinkage and deformation. |
| Minimum aperture | For injection molding Acetal (POM) small holes, the recommended hole diameter should not be less than 0.8mm-1.2mm. Deep small holes and slender holes need to be evaluated based on mold insertion needle strength, venting, and molding stability. Screw holes, positioning holes, shaft holes, and assembly holes should consider shrinkage, draft angle, and assembly requirements. High-precision shaft holes, gear holes, and sliding fit holes can be processed by injection molding, post-reaming, boring, or CNC post-processing. |
| Assembly clearance | For ordinary plastic parts, it is recommended to reserve 0.05mm-0.20mm on one side; for sliding fits, 0.10mm-0.30mm is recommended on one side; for movable, high-speed movement, or structures with large temperature changes, it is recommended to appropriately increase the clearance. Due to the low coefficient of friction in Acetal (POM), it is suitable for sliding fits, but the assembly should not be too tight, otherwise it may cause sticking, thermal expansion interference, or abnormal long-term wear. |
| Detailed performance | Injection molding Acetal (POM) can achieve clearer rib positions, column positions, snaps, tooth profiles, slots, steps, logos, and general functional details. Acetal (POM) materials have more stable molding details, and edge clarity is usually better than softer materials like Polypropylene (PP) and Polyethylene (PE). For raised text, recessed text, and fine textures, it is recommended to be no less than 0.3mm-0.5mm. Gears, slides, and sliding surfaces should prioritize functional dimensions and surface quality; it is not recommended to design complex decorative textures on high-wear surfaces. |
| Surface effect | The original surface of injection molding Acetal (POM) is usually white, black, natural color, or plastic after masterbatch color adjustment, resulting in a more delicate surface with lower friction and a harder feel. Acetal (POM) can be made into regular glossy finishes, matte finishes, fine textures, and functional textures, but they are not as suitable as ABS for high-gloss spray paint appearances. Acetal (POM) is more of an engineering functional material, suitable for internal structural parts, sliding parts, gears, and precision assemblies, but not suitable for transparent parts or high-end painted decorative parts. |
Based on material characteristics and suitable product ranges, customer needs are broken down into easier application directions to determine.
Plastic gears, sliders, guide rails, shaft sleeves, bushings, rollers, guide blocks, pads, wear-resistant plates, snap fasteners, connectors, button structural parts, small automotive functional parts, electronic and electrical structural parts, conveyor equipment parts, automation equipment parts, packaging equipment parts, precision plastic structural parts, low-friction moving parts, ordinary mechanical transmission parts.
Engineering plastic injection molding materials suitable for mass production of precision plastic structural parts, wear-resistant sliding parts, gears, shaft sleeves, rollers, guide parts, latch parts, mechanical transmission parts, and low-friction functional parts.
Injection molded Acetal (POM) have good rigidity, dimensional stability, wear resistance, and low friction properties, making them very commonly used materials in mechanical functional injection molded parts. It has a low water absorption rate and is less affected by humidity, making it more suitable than Nylon (PA) for precision assembly, gears, sliders, and shaft sleeve parts. Acetal (POM) has a harder surface and a delicate feel, with lower noise during movement, making it suitable for light-load or medium-to-low load transmission structures. However, Acetal (POM) is not suitable for environments with strong acids and alkalis, has poor adhesion to paint adhesion, and is also not suitable as a high-end paint appearance material.
Based on wall thickness, hole position, assembly clearance, dimensional tolerances, and material usage risks, determine in advance whether the part structure is suitable for Acetal (POM).
Post-processing of Acetal (POM) affects appearance, dimensions, hole position, assembly clearance, and usage validation results, and should be explained in advance during quotation, DFM review, and sample confirmation stages.
Post-processing should focus on appearance display, dimensional fitting, connection assembly, and testing verification. Parts involving assembly positions need to be reserved in advance for machining, coating, and trial assembly allowances.
For common issues such as threads, snaps, strength, temperature resistance, and weather resistance, identify in advance whether the material needs to be replaced or if another processing method should be used.
When customer demand exceeds Acetal (POM) material boundaries, it is necessary to combine strength, temperature resistance, toughness, long-term stability, and mass production goals to promptly recommend alternative materials or processing technologies.
If higher toughness and impact resistance are required, Nylon (PA), Polycarbonate (PC), or modified Acetal (POM) can be chosen; If higher temperature resistance and strength are needed, PPS, Polyether Ether Ketone (PEEK), or fiberglass-reinforced Nylon (PA) can be chosen; If you need better paint finishes, you can choose ABS or Polycarbonate (PC)+ABS; If higher chemical resistance and low friction are required, PTFE, PVDF, or Polyether Ether Ketone (PEEK) can be chosen; If lower-cost ordinary structural parts are needed, Polypropylene (PP) or ABS can be chosen; If higher rigidity and load-bearing capacity are required, aluminum alloy, stainless steel, or zinc-aluminum die-cast parts can be chosen.
If customers require wear-resistant, low-friction, dimensional stability, precision assembly, and medium- to low-load mechanical moving parts, injection molding Acetal (POM) is an excellent choice. If customers mainly focus on exterior paint, transparent effects, or high-toughness housings, Acetal (POM) is not a preferred material; If customers require long-term high temperatures, heavy loads, or highly corrosive environments, priority should be given to PPS, Polyether Ether Ketone (PEEK), PTFE, metal materials, or specialized modified materials. Acetal (POM) is suitable for "precision moving parts and wear-resistant structural parts," not suitable for "high-temperature heavy-duty parts and painted parts."
After uploading 3D/2D drawings and supplementing materials, quantities, tolerances, surface treatments, and delivery requirements, XPartsLab will provide next steps in 3D printing manufacturability, cost, and delivery pathways.
