Buy One Way Screws Online in Australia
One-Way / Anti-Theft Screw Quick Reference
One-way screws are tamper-resistant fasteners — driven in with a standard slotted screwdriver but designed so conventional tools can't remove them. The asymmetric drive recess engages in the drive direction only, slipping on reverse rotation. Used for security applications: panel covers, electrical enclosures, signage, access plates, public infrastructure. Removal requires either a dedicated one-way bit or destructive methods.
| Screw Type | Common Sizes | Drive Method | Best For |
|---|---|---|---|
| One-Way Pan Head | M3, M4, M5, M6 × various lengths | Slotted (one-way recess) — drives in but slips on reverse | Machine panels, electrical enclosures, equipment covers |
| One-Way Self-Tapping | 10G × 3/4" (Champion NPS7), 8G × 1/2" | Slotted self-tap into sheet metal | Sheet metal panels, signs, access covers, light security mounts |
| Snake Eye / Spanner Drive | M3, M4, M5, M6, M8 × various | Two-pin spanner — non-standard tool required | Higher security than slot one-way — vandalism resistance |
| Pin Hex (Tamper-Proof Hex) | M3, M4, M5, M6, M8 | Hex with centre pin — needs pin-hex bit | Common tamper-resistant — security cameras, equipment |
| Pin Torx (Tamper-Proof Star) | T10, T15, T20, T25, T30, T40 | Torx with centre pin — needs pin-torx bit | Higher security applications, electronic device assembly |
| Breakaway / Shear-Off | Various | Drives in normally; bolt head shears off when fully tightened | One-time install permanent security (signage, anchors) |
Security level scale: one-way slot (low — slot can be picked) → snake-eye / pin hex (medium) → pin Torx (medium-high) → shear-off (one-time permanent). Match the security level to the threat. For removal, dedicated one-way removal bits + pin-drive bits exist. Companion ranges: security fasteners, screws, self-tapping screws.
One Way & Anti-Theft Screws — Tamper-Resistant Security Fasteners
One-way screws are security fasteners engineered to be driven in using a standard slotted screwdriver but cannot be removed using conventional tools. The head geometry — typically a rounded or asymmetric drive recess — allows the driver to engage in the drive direction only, slipping out on the reverse. AIMS Industrial stocks one-way screws from Champion in metric and self-tapping configurations.
Metric One-Way Screws
Champion NPS5 M6 × 20 one-way screws are supplied in 50-piece packs. Suitable for machine panels, electrical enclosures and access covers where tamper-resistance is required but ease of installation with a standard tool is desired.
Anti-Theft Self-Tapping Screws
Champion NPS7 anti-theft self-tapping screws in 10G × 3/4" are supplied in 50-piece packs. Self-tapping variants are suited to sheet metal, plastic and thin-section applications — typical uses include public fixtures, signage mounts and equipment that requires weather-resistant tamper protection.
Applications
Common applications for one-way and anti-theft screws include: electrical meter boxes and switchboard covers, public seating and street furniture, access panels on commercial equipment, machinery guarding and covers, and any installation where unauthorised removal must be prevented.
Need a different size or drive type? Contact our team — we may be able to source other configurations.
People Also Ask — One-Way Security Screws
Q: What's a one-way screw?
A one-way screw is a tamper-resistant fastener with a drive head that allows tightening but resists loosening. The drive geometry typically uses curved or sloped ramps that engage a standard slotted screwdriver in one rotation direction (tightening) but slip in the other direction (loosening). Used for: public infrastructure security, retail anti-theft fixtures, licence plate mounting, vehicle anti-theft, and any application where unauthorised removal must be prevented.
Q: How do you remove one-way screws?
Difficult by design — that's the security feature. Removal methods: (1) drill out the screw with a drill bit, (2) cut a slot across the head for screwdriver leverage in reverse direction, (3) use specialty one-way screw extractors (rare), (4) destructive removal with screw extractors or chisels. For installations where you might need to remove the screw later: don't use one-way screws. They're permanent or near-permanent fasteners.
Q: What sizes do one-way screws come in?
Common workshop sizes: M4, M5, M6, M8 metric; #6, #8, #10 imperial. Head styles: countersunk, pan, and oval head are most common. Materials: zinc-plated steel (general security), stainless 304/316 (outdoor and marine), aluminium (lightweight applications). Length range typically 8-50mm. Match to the application (substrate thickness + protrusion required). For workshop kit, common sizes covers most security applications.
Q: When should I use one-way screws?
Public infrastructure where unauthorised access prevention is the primary requirement. Permanent or near-permanent installations where future access isn't anticipated. Applications where the cost of theft outweighs the inconvenience of difficult removal. Don't use where: regular service access is needed, the installation might need to move, the operator may need to replace the fasteners themselves. The one-way design is a permanent commitment.
Q: Alternative security fasteners?
If you might need to remove the screws later but want security: pin-Torx fasteners (require specialty pin-Torx bits but can be removed with the right tool), snake-eye fasteners (two-hole drive — same principle), or breakaway head bolts (snap off at the head, leaving smooth surface that prevents standard tool engagement). For applications requiring authorised removal capability + security: pin-Torx or snake-eye. For permanent: one-way or breakaway. See [Security Fasteners collection](/collections/security-fasteners).