| Brass | Approximately 8.4–8.7 g/cm³ | Copper-zinc alloy with good ductility, machinability, electrical conductivity, and a warm metallic appearance. | Generally good resistance to normal atmospheric exposure. It can tarnish or develop a patina over time, especially in humid or chemically active environments. | Suitable for stamping, forming, machining, and decorative plating. Its ductility supports smooth snap engagement and reliable forming. | Fashion apparel, leather goods, handbags, footwear, denim, decorative closures, and products where appearance and a premium metallic feel are important. | Heavier than zinc alloy and stainless steel in many comparable designs. Surface color may change if an uncoated finish is exposed to moisture, sweat, or chemicals. | Specify alloy grade, plating or lacquer system, surface-color tolerance, nickel-release requirements, and corrosion-test conditions before approval. |
| Stainless Steel | Approximately 7.7–8.0 g/cm³ | Iron-based alloy containing chromium; common austenitic grades provide high toughness, strong durability, and excellent resistance to wear. | Chromium forms a passive oxide layer that provides strong resistance to rust and staining. Performance depends on grade, surface condition, chloride exposure, and manufacturing quality. | Supports durable stamping, wire forming, machining, and polishing. It is well suited to long-service components exposed to frequent handling or washing. | Outdoor apparel, marine or coastal products, workwear, luggage, equipment covers, washable goods, and applications requiring high durability and low maintenance. | Usually more difficult to form and machine than brass or zinc alloy. Material and processing costs can be higher, and its appearance may be less decorative without additional finishing. | Confirm the exact grade, such as an austenitic grade suitable for the environment, along with salt-spray criteria, passivation requirements, burr control, and magnetic expectations. |
| Zinc Alloy | Approximately 6.6–6.7 g/cm³ | Die-cast alloy offering good dimensional repeatability, complex-shape capability, and a relatively low weight compared with brass and stainless steel. | Provides useful atmospheric corrosion resistance, but exposed surfaces can develop white corrosion products in prolonged humidity or salt exposure. Protective finishing is commonly used. | Highly suitable for die casting, enabling integrated decorative shapes, logos, recessed details, and large-volume production with consistent dimensions. | Decorative fashion snaps, accessories, bags, footwear, promotional products, and medium-duty closures where shape flexibility and cost efficiency are priorities. | Less suitable for severe impact, high-temperature service, or continuous saltwater exposure. Brittle failure and coating damage should be evaluated in heavy-duty designs. | Define casting porosity limits, plating thickness, adhesion testing, coating inspection, dimensional tolerances, and packaging protection against humidity during transport. |
| Brass | Approximately 8.4–8.7 g/cm³ | Strong visual compatibility with antique, vintage, gold-tone, and natural metal finishes. | Uncoated surfaces may darken or patinate; clear protective coatings can help maintain appearance but require adhesion and wear testing. | Well suited to embossed details, polished surfaces, and plated finishes when appearance consistency is carefully controlled. | Premium visual collections, heritage-style garments, luxury leather accessories, and products where the snap is a visible design element. | Finish variation can occur between production lots if base-metal preparation and plating controls are inconsistent. | Approve a physical color standard and define acceptable variation under the intended lighting conditions. |
| Stainless Steel | Approximately 7.7–8.0 g/cm³ | Strong, stable, and resistant to repeated opening and closing when the snap geometry and temper are properly designed. | Typically retains a clean appearance better than untreated brass or zinc alloy in humid and frequently handled applications. | Appropriate for high-cycle products where spring performance, wear resistance, and structural integrity are more important than decorative complexity. | High-use garments, technical textiles, outdoor equipment, reusable covers, and products exposed to repeated washing or abrasion. | Excessive work hardening, sharp edges, or unsuitable tooling can affect assembly quality and user comfort. | Validate opening force, closing force, cycle life, edge radius, and compatibility with the fabric or substrate thickness. |
| Zinc Alloy | Approximately 6.6–6.7 g/cm³ | Lower density and strong design freedom make it practical for larger decorative components that should not feel excessively heavy. | Long-term performance is strongly influenced by plating, paint, clear coating, storage humidity, and exposure to sweat or salt. | Efficient for complex three-dimensional shapes and repeat production when die-casting tooling is amortized over sufficient volume. | Large decorative snaps, statement accessories, fashion hardware, and cost-sensitive programs requiring detailed shapes. | Die-cast surfaces may contain porosity or require additional finishing. Thin plating or poor sealing can reduce service life. | Request first-article samples, coating cross-hatch tests, humidity testing, and dimensional inspection before mass production. |