Comparison : Item # Z400505, Slotted Round Head Machine Screws, National Coarse, Zinc Plated Steel (1/4"-20)
Item # Z400510, Slotted Round Head Machine Screws, National Coarse, Zinc Plated Steel (1/4"-20)
Item # Z400515, Slotted Round Head Machine Screws, National Coarse, Zinc Plated Steel (1/4"-20)
Item # Z400520, Slotted Round Head Machine Screws, National Coarse, Zinc Plated Steel (1/4"-20)
Item # Z400525, Slotted Round Head Machine Screws, National Coarse, Zinc Plated Steel (1/4"-20)