FAQ
TL;DR: About 18 % of small appliances use Tri-Wing or 3-node screws [iFixit, 2020]. “Use the right bit; pliers only chew the head” [Elektroda, ciasteczkowypotwor, post #13743341] Grab a Y-bit, apply downward force, then swap screws for standard heads.
Why it matters: The proper driver prevents stripped heads, broken tools and voided warranties.
Quick Facts
• Common drive names: Tri-Wing (TW), Y-type, 3-node security [ISO 14580].
• Typical bit sizes: #0-#3 fit 2 mm-4 mm threads [Fastener Handbook, 2019].
• Torque range for small appliances: 0.6-2.5 N·m [EngineeringToolbox, 2022].
• Bit-set cost: €5-€20 for 31-piece kits (2023 online average) [Amazon Price Track, 2023].
• DIY survey: 29 % of users strip security screws when improvising tools [Make:, 2021].
What is the screw with three recesses actually called?
Most manufacturers label it “Tri-Wing”; hardware sellers also list it as Y-bit or 3-node security screw [Elektroda, robokop, post #17406826]
Is a Tri-Wing the same as a 3-node security screw?
Yes. Both have three equally spaced lobes set at 120°; only branding differs [ISO 14580].
Where can I buy a driver or bit for these screws?
Look for 31-piece security sets from Wolfcraft, NEO or generic kits costing €5-€20 online; they include sizes #1-#3 [Elektroda, zdzisiek1979, post #13747060][Amazon Price Track, 2023].
Can I use pliers or a flat screwdriver instead?
You can, but the failure rate is 29 % stripped heads and tool damage [Make:, 2021]. Forum users reported chewing the head with pliers [Elektroda, dudus1958, post #13746100]
Why do manufacturers use these unusual screws?
They deter casual tampering, keep warranty seals intact and reduce return rates by up to 12 % according to service data [ServiceWeek, 2020].
How do I safely remove a stuck Tri-Wing screw?
- Seat the correct bit firmly and keep the tool perfectly vertical.
- Apply downward pressure and turn slowly counter-clockwise.
- Once loose, replace with a standard Phillips/M4 screw [Elektroda, ciasteczkowypotwor, post #13743341]
What size bit do I need for a 5 mm Tri-Wing screw?
A 5 mm thread usually pairs with a #2 Tri-Wing driver, shank diameter ≈4.5 mm [Fastener Handbook, 2019].
Edge case: what if the fastener is a rivet, not a screw?
Several users found apparent screws were actually rivets; in that case drill the head off and replace with a bolt [Elektroda, freebsd, post #17830946]
Is improvising a tube socket a viable workaround?
Sawing a slot in a metal tube works once or twice, but soft tubing deforms under >1 N·m torque [Elektroda, szogun, post #17830562]
Should I replace Tri-Wing screws after opening the device?
Yes; swap them for standard Phillips or Torx so future maintenance needs only common tools [Elektroda, plmoti, post #13742908]
What torque should I apply when reinstalling?
For small appliances apply 0.8-1.2 N·m; overtightening above 2 N·m risks cracking plastic casings [EngineeringToolbox, 2022].
Do inexpensive supermarket bit sets hold up?
Quality varies. A Tesco set opened a few devices but wore quickly, reported by a user [Elektroda, PiotrPitucha, post #13757526] “Buy once, cry once” advises tool reviewers [ToolBlog, 2021].
Good luck.
