The 27mm bi‑hex socket with a 1/2in square drive is a metric socket designed to engage 12‑point (bi‑hex) fasteners and standard hexagonal bolts. Its primary use is general workshop and maintenance work where a 1/2in drive ratchet, breaker bar or torque wrench is used to apply or remove threaded fasteners on vehicles, plant and equipment.

This socket is manufactured from heat‑treated chrome‑vanadium (Cr‑V) steel and finished with a bright chrome plating to provide surface corrosion resistance and to ease cleaning. The bi‑hex (12‑point) profile allows engagement every 30°, which makes it easier to locate the socket on fasteners in confined spaces compared with 6‑point variants. The socket accepts a standard 1/2in (12.7mm) square drive tool and is compatible with common drive retention systems such as spring detent balls or friction rings as used on ratchets and extensions. Manufactured to recognised DIN/ISO/BS standards for hand sockets, the part is suitable for professional workshop use and meets typical dimensional and strength requirements for industrial sockets.

Typical applications include automotive repair and servicing, commercial vehicle maintenance, agricultural and construction equipment servicing, plant maintenance and light fabrication work. The 27mm size is commonly found on suspension, drivetrain and engine fastenings on cars, vans and many pieces of off‑road machinery, and it is frequently used by mechanics, service engineers and maintenance technicians.

Key benefits of this 27mm bi‑hex socket include the corrosion resistance from the chrome finish, the toughness and torque capacity afforded by heat‑treated Cr‑V steel, and the wide compatibility with standard 1/2in drive tools and accessories. The 12‑point profile speeds alignment in tight locations and reduces the time taken to engage fasteners, while the hardened steel construction helps resist rounding and wear under repeated use.

Duchy Fasteners stocks the 27mm 1/2in drive bi‑hex socket individually and as part of metric socket sets. Our range covers common metric sizes (typically from 8mm up to 32mm) and is available in single‑unit packs and multi‑piece sets to suit workshops and trade users.