Open-end/box wrench Unior U600379 28 mm, chrome-vanadium steel, single piece

Unior U600379 28 mm combined open-end/box wrench is a single-piece hand tool manufactured from chrome-vanadium steel. It features a closed 12-point ring at one end and an open jaw at the opposite end, designed to engage hexagonal fasteners and bolts. The tool is intended for medium to high torque applications and is suitable for automotive, mechanical and general maintenance work where a reliable, durable wrench is needed.

Advantages

The one-piece construction provides torsional strength and reduces the risk of joint failure compared with multi-piece designs. Chrome-vanadium steel construction delivers good hardness and wear resistance while the chrome finish helps protect against corrosion and facilitates cleaning. Having both a ring and an open end on the same 28 mm wrench increases versatility on the job, allowing fast switching between confined and more accessible fasteners without changing tools.

Suitable for

• Automotive repair and maintenance tasks involving 28 mm hex bolts and nuts
• Mechanical assembly and disassembly where medium to high torque is required
• Workshop and field service work that needs a durable, single-piece wrench
• Maintenance of agricultural and industrial equipment with compatible fasteners

When it may not be suitable

This 28 mm combined wrench is not suitable for fasteners that require torque values beyond manual capability or where a torque-limiting tool is required for precision tightening. It may also be impractical for very confined spaces where only a low-profile or crowfoot-style wrench will fit. For soft or plated fasteners where damage is a concern, alternative tools or protective measures should be considered.

Key specifications

• Size: 28 mm
• Type: combined open-end and 12-point box end (single piece)
• Material: chrome-vanadium steel
• Finish: chrome plated
• Application: manual turning of hexagonal nuts and bolts

How to use

Select the 28 mm size on the wrench and position either the ring end or the open jaw onto the fastener so the tool fully contacts the flats of the nut or bolt. Apply steady manual force in the required direction, keeping the wrench aligned with the fastener axis to minimise rounding. Use the ring end for better grip and reduced slippage on tightly torqued fasteners, and use the open end where the ring cannot reach. Do not use the wrench with impact tools or as a hammer.

What to consider before purchase

• Confirm the fastener size is 28 mm to ensure proper fit
• Assess working clearance to determine whether the ring or open end will be more practical
• Consider required torque levels and whether a torque wrench or powered tool is needed
• Prefer single-piece chrome-vanadium designs for durability in demanding use

Usage recommendations

Store the wrench dry and clean the chrome finish after use to maintain corrosion resistance. Inspect the tool regularly for rounding or wear at the jaws and ring; replace if fit becomes loose to avoid damage to fasteners. When higher accuracy of torque is required, use this wrench to position components and finish tightening with a calibrated torque wrench.