Comparison : Item # Z400030, Slotted Round Head Machine Screws, National Coarse, Zinc Plated Steel (4-40)
Item # Z400035, Slotted Round Head Machine Screws, National Coarse, Zinc Plated Steel (4-40)
Item # Z400040, Slotted Round Head Machine Screws, National Coarse, Zinc Plated Steel (4-40)
Item # Z400045, Slotted Round Head Machine Screws, National Coarse, Zinc Plated Steel (4-40)
Item # Z400050, Slotted Round Head Machine Screws, National Coarse, Zinc Plated Steel (4-40)