Torx Screwdriver

The straight-shaft Torx in a single size, with a security-Torx-compatible tip. Buy the one you reach for most, in the format that handles deep-recess Torx fasteners a T-handle or Y-handle can't enter. Available individually across the Torx sizes the 621 line covers.

The straight-shaft Torx is the format for two specific situations on a bike: deep-recess Torx fasteners (some derailleur hangers, some shifter-clamp covers), and the security-Torx variants that show up on certain e-bike battery hardware and some component fasteners where the manufacturer wants to make casual tampering harder. The tip geometry on this screwdriver engages both standard Torx recesses and the security-Torx with a center hole (sometimes called Torx-tamper-resistant or "security Torx").

The chrome-vanadium shank is hardened and tempered. The tip is black-oxide treated for corrosion resistance and a precise fit into the Torx recess. The black-oxide finish is the deliberate alternative to chrome plating for the tip: chrome plating adds a small amount of dimensional thickness, which on a Torx tip is the difference between a clean engagement and a tip that bottoms out before fully seating. The non-tip shank surfaces still carry trivalent chrome to ISO 1456:2009 for the corrosion resistance the rest of the tool needs.

Compatibility

The 621 line covers the Torx sizes used most often on bikes, sized per individual order. The most-reached sizes:

• T25: 6-bolt disc rotor bolts (the industry-standard rotor interface; covered by the security-Torx tip)
• T27: Some SRAM disc-brake hardware
• T30: Current Shimano and SRAM chainring bolts; some crank-arm fixing bolts

The straight-shaft format earns its place anywhere a Torx fastener sits below a recess that fouls a T-handle or Y-handle's cross-bar geometry.

Specs

• Single-size straight-shaft Torx screwdriver (size selected at order)
• Hardened, tempered steel blade
• Black-oxide tip treatment for corrosion resistance and recess fit
• Tip compatible with both standard and security-Torx (center-hole) recesses
• Three-material composition handle
• Hex bolster at the handle base for wrench-assist torque
• Trivalent chrome plating to ISO 1456:2009 on the non-tip shank surfaces
• Manufactured in Slovenia

Built in Zreče, Slovenia

Unior has been forging hand tools in Zreče since 1919, and sponsors professional road and mountain-bike race teams. The straight-shaft Torx screwdriver is the deep-recess counterpart to the T-handle and Y-handle Torx tools in the line; the security-Torx tip geometry is the same tip you'd find on the pro-shop Torx set, which means it covers both standard and security-Torx recesses without two separate tools in the drawer.

Pro tip from our mechanics

E-bike battery and motor-cover fasteners are where security-Torx most often shows up on a bike, alongside some component manufacturers' choice to use it on warranty-seal bolts. If a Torx bolt has a small raised pin in the centre of the recess, that's a security-Torx; a standard Torx driver won't engage. The 621 line's tip geometry handles both, so the same tool that drives a rotor bolt drives the battery-cover screw.

For the Torx-to-fastener map on a typical bike and the access-condition decisions between straight-shaft, T-handle, and Y-handle formats: Hex and Torx wrenches: how to pick the right tool for the job →.