Walfront 200Pcs M3 Grade 10.9 Countersunk Head Screw Kit Alloy Steel Machine Screws 4-25mm Corrosion Resistants Fasteners for Marine, Electronics, DIY Projects with Storage Case Black

• Premium Grade 10.9 Alloy Steel: Crafted with aerospace-grade alloy steel hardened to 10.9 rating, these screws withstand 1000+ N/mm² tensile strength 30% stronger than standard fasteners. Black oxide coating provides saltwater corrosion resistance, passing 500hrs salt spray testing for marine use.
• Precision Countersunk Design: Laser-engraved Torx TR20 drive ensures 6x better transfer than Phillips heads. 90° flat head seating creates seamless alignment (±0.1mm tolerance), perfect for CNC machining and electronics enclosures.
• 15 Sizes for Versatile Applications: From 4mm mini screws for PCB mounting to 25mm heavy-duty fasteners, this 200pc kit covers 90% of M3 applications. Includes 5 size groupings with color-coded compartments.
• Marine-Grade Zinc-nickel plating combined with dichromate passivation creates triple-layer defense against humidity. Tested to withstand 95% RH environments for 12 months without oxidation - ideal for boat engines and outdoor electronics.
• Professional Organization System: Military-grade PP case with shockproof foam insert keeps screws dust-free. Each compartment has engraved size labels and quantity indicators (40pcs/size average). Carry handle and IP54 rating make it jobsite-ready.

Description: These countersunk flat head hex screws. The screws are 10.9 grade alloy steel, resistant to rust and corrosion. There are 8 lengths for you to choose from, which can be generally used in home and office appliances, machinery, furniture, etc. Features: Material: 10.9 Quality alloy steel The color black Thread length: 4mm (30Pcs), 6mm (30Pcs), 8mm (30Pcs), 10mm (30Pcs), 12mm (20Pcs), 16mm (20Pcs), 20mm (20Pcs), 25mm (20Pcs) Thread diameter: 3mm (M3 ) Box size: 13 * 6.5 * 2.3cm / 5 * 2.6 * 0.9 " Quantity: 1 x Box of screws 200Pcs Package weight: 138g Type: hexagonal countersunk head Function: Fixation Package includes: 1 x box of screws 200Pcs