Fasteners

Fasteners are fundamental components for mechanical assembly and fixation, encompassing screws, nuts, washers, standoffs, threaded inserts, and similar hardware. They see widespread use in robotics, 3D printer frames, CNC machines, panel mounting, and DIY projects. Selecting the right fastener ensures structural integrity, vibration resistance, and long service life.

Types of Fasteners

• Metric Screws & Bolts: Common diameters M2 through M6; head styles include hex, pan, countersunk, and socket (Allen).
• Nuts: Hex nuts, wing nuts, flange nuts, self-locking nuts, T-nuts, and captive/insert nuts.
• Washers: Flat washers, split lock washers, toothed washers — essential for securing connections against vibration.
• Threaded Inserts & Tapped Blocks: Heat-set brass or stainless steel inserts to add metal threads to plastic parts; also square t-nuts for aluminum extrusions.
• Standoffs & Spacers: Female-female or male-female hex/round standoffs for mounting PCBs and panels at a desired height.
• Rivets & Pop Rivets: Provide permanent fastening for sheet metal assemblies.

Selection Criteria & Common Pitfalls

Material choice should match the environment: zinc-plated steel works well indoors, while stainless steel (A2/A4 grade) is necessary for outdoor or humid conditions. When fastening plastic parts, self-tapping screws may suffice, but in applications requiring repeated assembly/disassembly, brass inserts improve thread durability. Ensure the thread diameter and length are adequate for the load; threads that are too short risk stripping, and overtightening damages threads. Also consider wrench clearance for hex heads (e.g., 5.5 mm for M3) and countersink angle (typically 90°) when using countersunk screws.