Proto J111012L Box End Wrench 5/16 X 3/8 in 12 Pt

Product Description

The PROTO J111012L is a double-end box wrench sized 5/16 inch by 3/8 inch, built for fastener work in tight spaces where an open-end wrench cannot seat fully. Both ends feature 12-point box profiles, allowing the wrench to engage hex fasteners at 30-degree increments for repositioning in confined areas. Constructed from steel with a polished finish, this wrench is designed for repeated use in professional trade environments including HVAC, plumbing, and electrical work where small fasteners are common. It meets ASME B107.10 standards and carries a lifetime warranty.

This wrench is suited for residential and light commercial service work wherever 5/16 inch or 3/8 inch hex fasteners appear. Typical applications include equipment panels, motor mounting hardware, pipe fittings, and electrical enclosures. The compact overall length of 8.84 inches makes it practical in restricted access areas such as inside air handlers, electrical panels, and mechanical equipment cabinets. It is a single-piece hand tool requiring no power source, used by HVAC technicians, plumbers, electricians, and general mechanical service professionals.

Key Features

• Dual-size ends: 5/16 inch and 3/8 inch box openings in one tool
• 12-point profile allows repositioning at 30-degree increments in tight spaces
• Steel construction with polished finish for corrosion resistance and durability
• Meets ASME B107.10 standards for box wrenches
• Lifetime warranty from the manufacturer
• Compact at 8.84 inches overall length for restricted-access service work

Compatibility

Designed for use with standard 5/16 inch and 3/8 inch hex fasteners across residential and commercial HVAC, plumbing, and electrical applications.

Installation Notes

This is a hand tool requiring no installation. Ensure the box end is fully seated on the fastener before applying torque to avoid rounding the fastener head. When working in or around energized electrical equipment, follow NFPA 70E arc flash safety procedures and de-energize circuits where required. Keep the wrench clean and dry to maintain grip and finish.