Upgrade your workshop with this comprehensive 522-piece M3 and M4 Hex Socket Screw Kit. Whether you are repairing RC cars (drones/models), working on 3D printer maintenance, or handling precision electronics, this assortment provides the high-quality fasteners you need in one organized case.

Key Features:

• Premium Material: Screws are crafted from high-grade Black Carbon Steel for durability and strength. Washers are made from 304 Stainless Steel for corrosion resistance.
• Versatile Assortment: Includes a wide range of M3 and M4 sizes (8mm to 16mm lengths), covering both Flat Head (Countersunk) and Round Head styles.
• Complete Accessories: Comes with essential hardware including Nylon Lock Nuts, Flat Washers, O-rings, R-clips, E-clips, and Grub Screws.
• Ready to Use: Includes 2 matching Hex Keys (Allen Wrenches) so you can start working immediately.
• Organized Storage: Packaged in a sturdy 15-grid PP plastic box with clear labeling, keeping your parts sorted and easy to find.

Package Contents (522pcs Total):

• Screws (Black Carbon Steel):
  • M3 Series:
    • Flat Head: M3x8 (30pcs), M3x10 (30pcs), M3x12 (30pcs), M3x16 (30pcs)
    • Round Head: M3x8 (30pcs), M3x10 (30pcs), M3x12 (30pcs), M3x16 (30pcs)
  • M4 Series:
    • Flat Head: M4x8 (20pcs), M4x12 (20pcs)
    • Round Head: M4x8 (20pcs), M4x12 (20pcs)
• Nuts & Washers:
  • Nylon Insert Lock Nuts: M3 (20pcs), M4 (20pcs) - Stainless Steel
  • 304 Stainless Steel Flat Washers: M3 (20pcs), M4 (20pcs)
• Specialty Fasteners:
  • Red Silicone O-Rings (5x1mm): 20pcs
  • Galvanized R-Type Cotter Pins (1.5x28mm): 20pcs
  • Dowel Pins (φ2x10mm): 20pcs
  • Black Manganese Steel E-Clips (3.0mm): 20pcs
  • Hex Set Screws (Grub Screws) DIN913: M3x3 (20pcs), M4x4 (20pcs)
• Tools & Storage:
  • Hex Key φ1.5mm (for M3 set screws): 1pc
  • Hex Key φ2.0mm (for M4 set screws): 1pc
  • 15-Grid Plastic Storage Box (17.8 x 10.5 x 2.3cm): 1pc