& Lowe's : Generally stock common metric hex bolts and socket caps, though they may lack more niche thread pitches.
: Usually have numbers like 8.8, 10.9, or 12.9 indicating strength. where to buy metric bolts
: Excellent for buying "assortment kits" that give you a range of lengths in a specific diameter (like an M3 or M4 kit), which is helpful for hobbies like 3D printing. & Lowe's : Generally stock common metric hex
: Usually have radial slashes (e.g., three marks for Grade 5). : Usually have radial slashes (e
: A popular choice for high-quality fasteners in low quantities with much better pricing than standard hardware stores.
or O'Reilly Auto Parts : Best for automotive-specific metric bolts, though they may not carry general-purpose hardware. Specialty & Online Suppliers (Best for Variety & Quality)
: The gold standard for professional projects. They carry almost every conceivable size with exceptionally fast shipping, though they often require buying in small packs rather than individuals.