M4 Nickel Plated Slot Head Binding Barrels and Screws

M4 nickel-plated binding barrels and screws for removable clamping joints. Each set pairs an internally threaded barrel/post with a matching M4 screw; choose 20 mm, 25 mm, or 30 mm barrel length.

Why use binding barrels here

• Removable two-piece fastener: the barrel and screw clamp material from both sides, so panels, plates, folders, leather, fixtures, and printer mods can be opened again later.
• M4 internal thread: the screw and barrel are M4-threaded even though the outside of the barrel may be listed elsewhere by its roughly 5 mm outer diameter.
• Nickel-plated finish: silver-tone plating gives a clean, corrosion-resistant surface for visible hardware.
• Slotted head: installs with a flat-blade screwdriver; no hex key required.

Specifications

• Thread: M4 internal barrel thread with matching M4 screw
• Barrel lengths: 20 mm, 25 mm, or 30 mm
• Finish: nickel plated, silver tone
• Fastener style: binding barrel / binding post / Chicago screw / sex bolt
• Drive: slotted head

Intended use

Useful anywhere you need a clean removable post-and-screw joint: bookbinding, leather and strap work, panels, brackets, fixtures, and 3D-printer projects that call for a binding screw or sex bolt. For Voron-style endstop work, compare the length and outside barrel diameter against the original BOM before ordering.

Pick the right length

• 20 mm: shortest stocked barrel, best when the clamped stack is thin.
• 25 mm: mid-length option when 20 mm is too short.
• 30 mm: longest stocked option for thicker stacks or spacer-style use.

What it is not

• Not a standard socket-head cap screw or machine screw by itself; it is a two-piece binding post set.
• Not guaranteed to fit every “M5 sexbolt” BOM callout unless the BOM is referring to the barrel outside diameter and the required length matches.