#3 Diameter Screws

Welcome to the “3-Diameter Screws” collection at Old West Iron. This section gathers our decorative and functional screws organized by shank diameter (also known as gauge) rather than by head size. Screws are grouped by their shaft thickness — from #3 through #24 — to help you find the right screw thickness for your project quickly and reliably. Whether you’re doing fine woodworking or heavy-duty construction, choosing by shank diameter ensures proper size and strength for structural integrity and secure fit.

FAQ

Q: Why are the screws grouped by diameter instead of head size?
A: Screws are sized based on their shank diameter — the thickness of the shaft — because that determines their holding strength and suitability for different materials and load requirements. Head size may vary for design or functional reasons, but the shank (or gauge) determines structural performance. 

Q: What does “# 6,” “# 10,” or “# 14” mean?
A: The “#” gauge number refers to the screw’s diameter: higher numbers indicate thicker screws. For example, a #6 screw has a thinner shank than a #10 screw. 

Q: How do I choose the right screw diameter for my project?
A: Use smaller-gauge screws (e.g. #4 or #6) for light-duty tasks like attaching trim or hardware. Use larger-gauge screws (e.g. #10, #12, or above) when you need greater strength — for furniture, structural woodwork, or heavy builds. 

Q: Can I mix screws with different head sizes but the same diameter?
A: Yes — because the grouping is by shank diameter, you may find screws with different head styles or finishes under the same diameter category. Head design affects appearance or installation method, but not the nominal strength of the screw.

Q: Are these screws suitable for structural applications?
A: That depends on the gauge and length. For heavy load or structural projects, choose a larger diameter and sufficient length. If in doubt, a lag or bolt may be more appropriate for high-stress connections.