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Gray Tools 3178B combination wrench, 12-point, black oxide finish

Gray Tools

Gray Tools 3178B Combination Wrench 12 Point Black Oxide

SKU CH-SXMJ-H9R27

A 12-point combination wrench with a corrosion-resistant black oxide finish for a secure fit on 2-7/16 inch fasteners

  • 12-point broached opening grips fastener flats securely
  • 2-7/16 inch hex size fits large bolts and nuts
  • Black oxide coating resists corrosion during heavy use
  • Meets ANSI dimensional standards for professional reliability
  • Brand-new Gray Tools 3178B combination wrench ready for work

Professional 12-Point Combination Wrench

The Gray Tools 3178B is a single-piece combination wrench built for mechanics and technicians who need a reliable 2-7/16 inch hex size. Its 12-point broached opening provides multiple engagement angles for faster fastener access in tight engine bays or industrial equipment. The black oxide coating adds corrosion resistance for daily shop use.

Upgrade from worn or rounded open-end tools

This wrench replaces adjustable wrenches or damaged fixed-size spanners that slip on stubborn bolts. The precision broaching ensures a secure fit on 12-point and compatible 6-point fasteners, reducing rounding risk. The jump is worth it when a technician repeatedly works on the same large hex size and needs consistent torque transfer without play.

Handles high-torque applications on large hex

The 2-7/16 inch capacity suits heavy-duty automotive, agricultural and industrial maintenance tasks. It delivers solid leverage for seized bolts on suspension components or machinery mounts. Headroom runs out when clearance demands a ratcheting box end or when the fastener exceeds the fixed 2-7/16 inch opening.

Highlights

  • 12-point broached opening grips fastener flats securely
  • 2-7/16 inch hex size fits large bolts and nuts
  • Black oxide coating resists corrosion during heavy use
  • Meets ANSI dimensional standards for professional reliability
  • Brand-new Gray Tools 3178B combination wrench ready for work

Specifications

BrandGRAY TOOLS

Questions about this item

What size fastener does the 3178B wrench fit?

The 3178B combination wrench fits a 2-7/16 inch hex fastener with its 12 point box end.

How do I properly seat the wrench on a stubborn bolt?

Fully engage the 12 point box end squarely on the fastener before applying force to avoid rounding the corners.

Will the black oxide finish wear off with heavy use?

The corrosion resistant black oxide finish will gradually wear on contact surfaces but continues to protect the underlying steel.

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