Molly Bolts vs. Toggle Bolts
Comparing 2 standards across 12 specifications. 12 key differences identified.
The Hollow Wall Anchor (Molly Bolt, patented by George F. Croessant in 1934) is an all-metal expansion fastener featuring a slotted steel sleeve that permanently crimps into 4 outward-flaring legs behind hollow drywall or plaster. Unlike toggle bolts, the anchor sleeve remains permanently clamped to the wall, allowing the machine screw to be removed and re-inserted repeatedly.
The Toggle Bolt (Butterfly Anchor / Spring Toggle) is a two-piece hollow cavity anchor consisting of a long machine screw threaded through a spring-loaded dual-winged metal crossbar. When pushed through a pre-drilled wall hole, the wings snap open inside the hollow wall cavity, distributing heavy pull-out tension across the rear face of drywall, plaster, or hollow cinder block.
Specification Comparison Table
12 Parameters| Parameter / Spec | ||
|---|---|---|
|
Sleeve Material
|
Pre-slotted zinc-plated cold rolled steel sleeve with barbed anti-spin collar | — |
|
Internal Machine Screw Thread
|
M4, M5, M6 (Metric) or 1/8", 3/16", 1/4" (Imperial) | — |
|
Grip Range Sizing
|
Short (1/8" to 3/8" wall thickness), Medium (3/8" to 1/2" drywall), Long (5/8" to 1" double-drywall/lath) | — |
|
Permanent Retention
|
Yes (Sleeve stays permanently crimped into the wall when screw is removed) | — |
|
Setting Method
|
Tightening the screw with a screwdriver or using a specialized manual Molly setting plier tool | — |
|
Safe Shear Load (1/2" Drywall)
|
Up to 50 lbs (23 kg) shear per anchor | — |
|
Assembly Components
|
— | Truss-head / round-head machine screw (typically 1/8", 3/16", 1/4", 3/8" or M4, M5, M6, M8) + spring toggle wings |
|
Required Clearance Hole
|
— | Large borehole required to pass folded wings (e.g. 1/4" toggle requires 5/8" [16 mm] hole) |
|
Substrate Compatibility
|
— | Drywall (1/2" & 5/8"), lath & plaster, hollow concrete masonry blocks (CMU), ceiling drywall |
|
Working Mechanism
|
— | Spring-loaded carbon steel wings snap open to 180° perpendicular clamp bar behind wall |
|
Safe Working Tension Load (1/2" Drywall)
|
— | 1/4" Toggle: ~50–90 lbs (22–40 kg) tension / ~100–150 lbs (45–68 kg) shear |
|
Single-Use Disassembly Warning
|
— | If screw is fully removed, the toggle wings fall permanently down inside the wall cavity |