Molly Bolts vs. Self-Drilling Drywall Anchors
Comparing 2 standards across 13 specifications. 13 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 Self-Drilling Drywall Anchor (EZ-Ancor / Zip-It / WallDog) is a wide-threaded, pointed nylon, zinc, or cast alloy anchor that drives directly into drywall sheets using a standard Phillips screwdriver without pre-drilling. Its deep, aggressive external threads bite into the gypsum core, providing fast and clean installation for lightweight wall fixtures.
Specification Comparison Table
13 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 | — |
|
Material Options
|
— | Die-cast Zinc Alloy (high strength / fire rated) or Engineered Polyamide Nylon |
|
Pre-Drilling Requirement
|
— | None (Sharp self-piercing tip and cutting flute drills its own hole directly through sheetrock) |
|
Drive Recess
|
— | Phillips #2 / Pozidriv #2 / Slotted Combo |
|
Mating Screw Required
|
— | Included #6 or #8 sheet metal/wood screw (typically 1-1/4" length) |
|
Substrate Compatibility
|
— | 1/2" and 5/8" Gypsum Wallboard (Drywall/Sheetrock) |
|
Safe Shear Load Rating
|
— | Zinc model: up to 50 lbs (23 kg) / Nylon model: up to 30 lbs (14 kg) in 1/2" drywall |
|
Stud Collision Behavior
|
— | Zinc models can pierce wooden wall studs; nylon models will snap if driven into a hidden stud |