You can freely build on The Invention of the Phillips Head Screw
This patent expired in 1954. Every claim — 0 independent, 0 dependent — is now unenforceable. Anyone can use, reproduce, manufacture, sell, or offer for sale this technology without a license.
Original assignee
Phillips Screw Co
Patent granted
1936
Expired
1954
Forward citations
8
What this patent covers
The patent describes a screw with a cruciform, or cross-shaped, recess in the head. This shape allows a matching screwdriver tip to self-center, meaning the tool naturally stays in the middle of the screw head as it turns. By increasing the surface contact area between the tool and the screw, it allows for higher torque without the screwdriver slipping out of the slot. This design was specifically engineered to be used with power-driven tools on assembly lines.
What is now free to use
All 0 claims of US 2046343 are in the public domain. Specifically:
The 0 dependent claims add narrowing limitations and are also free.
What is NOT covered
Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.
Does not cover standard flat-head or slotted screws.
Does not cover hex-key or Allen-style internal drive systems.
Does not cover square-drive or Robertson head screws.
Does not cover external bolt heads that require a wrench.
Who is building on this today
The Phillips Screw Company continues to license and manage the intellectual property surrounding this design. Thousands of global fastener manufacturers produce these screws daily, as the design has become a universal standard for assembly.
Products built on expired version of this technology
Most consumer electronics assembly
Automotive manufacturing fasteners
General household construction screws
Furniture assembly kits
How to cite this patent in your documentation
Phillips Screw Co. US Patent 2046343. Screw. Granted 1936, expired 1954. Now in the public domain.
Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.
PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.