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MEGA Flat Boxes

High-Capacity Design




A flat box is used in conjunction with a flat box handle to efficiently apply a crowned, feathered coat of joint compound over taped joints on walls and ceilings. DEWALT MEGA flat boxes hold up to 30% more joint compound than DEWALT standard flat boxes.

DEWALT MEGA flat boxes feature a premium grade aluminum housing that has been hard-coat anodized for extreme durability and easy cleaning. They are fitted with a flexible brass blade holder and a stainless steel blade, as well as stainless steel skids and shoes. A crown adjustment dial provides 5 settings, so the ideal amount of compound can be dispensed on the wall to ensure consistent, professional results. 

DEWALT MEGA flat boxes have a premium composite pressure plate seal and beveled edges on the box housing ensure easy open and close. The pressure plate itself also opens extra wide for easy cleaning.  They are outfitted with non-marring wheels with durable bearings for ultra-smooth operation.  Our 7” and 10” versions also come standard with “outsider” wheel extensions for use when finishing outside corner beads.


  • Joint edges are feathered to perfection.
  • Efficiently applies an even, consistent layer of joint compound to taped flat and butt joints on walls and ceilings.
  • Flexible brass blade holder and SS blade allows for proper compound application and crown.
  • Adjustable crown dial ensures the precise amount of mud.
  • DEWALT automatic drywall tools are backed by a 10-year limited warranty.


DEWALT “Outsider” wheel extensions for finishing outside corner beads (DXTT 2-862). Comes standard with 7” and 10” DEWALT MEGA flat boxes.

DEWALT extendable flat box handles are available in four lengths:

  • 23” – 32” (DXTT 2-782)
  • 30” – 42” (DXTT 2-781)
  • 40” – 62” (DXTT 2-780)
  • 48” – 78” (DXTT 2-759)



All DEWALT automatic taping tools come with a ten (10) year warranty to the original owner that these products will be free from defects in materials and/or workmanship under normal operating conditions.


The DEWALT Drywall MEGA Flat Box is Guaranteed Tough® and backed by DEWALT‘s Nationwide Service Network. We back all of our tools with the best warranties in the industry and they are guaranteed to exceed your expectations.

Have questions about your DEWALT drywall tools? Send us as an email ( or give our toll-free support line a call (800.820.0647). If you need any assistance, parts or tool maintenance, our service center is located in Kansas and our technical experts are just a call away.


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Automatic Taping Tools

DEWALT Drywall Tools warrants to the original owner that all of its automatic drywall taping tools will be free from defects in material and function for a period of ten (10) years from date of purchase excluding commonly replaced wear parts. This warranty is valid only in the USA, Canada, Australia, the United Kingdom and Europe. A one (1) year warranty applies in all other countries/markets.

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