🔩 A2 Stainless Steel Butterfly Wing Thumb Screws with Washer — Hand-Tighten in Seconds
Reaching for a screwdriver every time you adjust a jig, swap an access panel, or tweak a 3D printer frame gets old fast. These double-head butterfly wing thumb screws — trusted by makers, machinists, and hobbyists — are built for exactly that. The wide dual-wing head gives you a firm, slip-free grip so you can tighten and loosen by hand in seconds, even with work gloves on.
Each set includes one thumb screw plus one matching flat washer, so load spreads evenly and your mating surface stays protected — no separate washer hunt required. Built from A2 stainless steel (304 equivalent), these metric hand knob screws won’t rust in a damp shop, outdoor enclosure, or humid environment. Available in metric sizes M3 through M16 and lengths from 16 mm (⅝”) to 250 mm (≈9.8”) — pick the exact size you need. The 5-set packs offer the best cost-per-piece for full builds.
Whether you need a captive thumb screw for a CNC fixture, a metric thumb bolt for a woodworking jig, or a stainless hand knob screw for an outdoor enclosure panel — this is the one to reach for.
🔗 Universal Metric Fit: Standard ISO threads — compatible with any M3–M16 metric nut, hex nut, T-nut, threaded insert, or tapped hole of the matching size. No adapters needed.
✅ Key Features of These A2 Stainless Wing Thumb Screws
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🤜Double-head butterfly wing grip — wider than single-wing hand knob screws; tighten firmly by hand without slipping, even with gloves
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🧲Flat washer included per screw — protects mating surfaces and distributes clamp load; no separate sourcing needed
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⚙️A2 stainless steel (304 equiv.) — corrosion-resistant metric thumb screws rated for indoor, outdoor, and humid workshop environments
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📏Full metric range M3–M16 — covers the most common thread sizes in DIY, CNC, fabrication, and light industrial work
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📐Lengths 16 mm to 250 mm — short sizes for panel work; long captive thumb screw lengths for through-assembly and deep-stack fixtures
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📦1-, 2-, and 5-set packs — buy exactly what you need; 5-set delivers the best per-unit value for full builds
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⚡Tool-free install & removal — ideal for inspection covers, jig clamps, enclosure panels, and frequent-adjustment applications
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✨Clean, consistent finish — smooth ISO metric threads, uniform wing geometry, no sharp edges or casting flash
📐 Technical Specifications — Metric Butterfly Thumb Screw with Washer
| Material |
A2 Stainless Steel (304 equivalent) |
| Head Style |
Double-Head Butterfly Wing Thumb Screw |
| Washer Included |
Yes — one flat washer per thumb screw |
| Thread Standard |
Metric ISO |
| Thread Sizes |
M3, M4, M5, M6, M8, M10, M12, M14, M16 |
| Length Range |
16 mm (5/8”) – 250 mm (≈9.8”) — varies by thread size |
| Pack Options |
1 Set / 2 Set / 5 Set (1 screw + 1 washer per set) |
| Drive Method |
Hand-tightened — no tool required |
| Corrosion Resistance |
Yes — suitable for damp and outdoor use |
| Finish |
Natural stainless (mill / brushed) |
| Compatible Hardware |
M3–M16 metric nuts, T-nuts, threaded inserts, tapped holes |
| Common Applications |
Jigs, CNC fixtures, 3D printer frames, enclosures, access panels, woodworking clamps |
❓ Frequently Asked Questions
What’s included in each set?
Each “set” is one double-head butterfly wing thumb screw plus one matching flat washer. A 5-set pack gives you 5 screws and 5 washers. The washer diameter is sized to match the thread of the screw in that listing.
How do I choose the right length?
Measure the total stack thickness of the material(s) you’re fastening through, then add enough thread engagement — at least 1× the bolt diameter for steel, 1.5–2× for aluminum or plastic. For example, fastening through 10 mm (≈3/8”) of material into a steel nut typically calls for an M6 × 20 mm or M6 × 25 mm. When in doubt, size up slightly — you can always add a spacer or extra nut.
Are these strong enough for structural or load-bearing use?
A2 stainless offers solid tensile strength for most workshop and light industrial tasks — jig clamping, panel retention, fixture assembly. Because these are hand-tightened metric thumb bolts, they won’t reach the clamp load of a torqued hex bolt. For high-vibration or structural joints, use a standard hex fastener. For access panels, adjustable fixtures, and frequent-removal applications, these are the right tool.
Can I use these outdoors or in a humid environment?
Yes. A2 stainless (304 grade equivalent) handles rain, condensation, and mild chemical exposure reliably. It’s a solid choice for outdoor enclosures and damp workshops. For saltwater or highly corrosive settings, A4 (316) stainless is the better option — but for typical shop and outdoor cabinet use, A2 performs well.
Will these fit standard metric nuts and threaded inserts?
Absolutely. Standard metric ISO threads — compatible with any matching metric nut, hex nut, wing nut, T-nut, threaded insert, or tapped hole. M5 thumb screws pair with M5 nuts, M8 with M8 nuts, and so on. No adapters required.
Which pack size should I order?
For a quick fix or prototype, the 1- or 2-set options keep it simple. If you’re outfitting a full machine, jig, or enclosure — or want spares on hand — the 5-set pack gives you the best cost-per-piece. All pack sizes ship the same screw and washer combination.
🛒 Select your thread size and length above, then add to cart — ships from our US warehouse.
