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Keep-Nut® Undermount Sink Anchors for Stone, Quartz & Porcelain

Keep-Nut® Undermount Sink Anchors

Faster, Stronger, Epoxy-Free — Universal Anchoring for Stone, Quartz, Porcelain & Solid Surface

Keep-Nut® is a high-strength, stainless steel insert system that eliminates adhesives and curing time for undermount sink installations. Designed for speed and precision, Keep-Nut installs flush for a professional finish in stone, quartz, porcelain, solid surface, and more. Trusted by fabricators nationwide, it delivers the durability, reliability, and efficiency you need on every project.

Keep-Nut Anchors in Use

Why Fabricators Choose Keep-Nut®

  • Exceptional holding power – tested pull-out resistance up to 650 lbs.
  • Versatile across materials – works in granite, quartz, porcelain, Corian®, UHPC, and more.
  • Fast, epoxy-free installation – no adhesives, no mess, installs with manual tools, CNC machines, or the KDM115 system.
  • Durable stainless steel design – fully corrosion-resistant and fireproof for long-lasting performance.
  • Clean, professional finish – anchors are hidden and flush-mounted.
  • Certified reliability – ASTM and ETA tested for proven structural strength.
Keep-Nut Kit

Installation Videos

CNC Router Installation

Manual Drilling Installation

Solid Surface Installation

*For best view on mobile, please scroll tables left/right.

Keep-Nut Sets & Starter Kits

Product Description Photo
Full Sink Mounting Set Full set of Inserts and Hardware. Most sinks take 4 sets. Mounting Set
Starter Kits Includes all the essential tooling needed to begin. Starter Kit

Inserts, Fasteners & Clips

Product Description Photo
Keep-Nut™ Inserts (100-Pk) 100 Pack of Keep-Nut Inserts Only. Inserts
Mounting Hardware (100-Pk) Allen Posts, Wing Nuts, and Washers. Hardware
Z-Shaped Sink Clips (100-Pk) Stamped metal clips, Made in USA. Sink Clips

Installation Tools

Tool Function Photo
Go/No-Go Gauge Verifies correct hole dimensions prior to install. Gauge
Keep-Nut Setting Tool Ensures insert installs flush and protects surface. Setting Tool
KDM115 Drilling Machine Vacuum base drill with water feed & depth stop. KDM115

Drilling Bits – CNC & Manual

Bit Method Use Case Photo
CNC Bit (Blue – 11.8 mm) CNC Router Quartz, Stone Blue CNC
CNC Bit (White – 11.8 mm) CNC Router Porcelain White CNC
Manual Bit (Blue – 11.4) Grinder / KDM115 Quartz, Stone Blue Manual
Manual Bit (White – 11.4) Grinder / KDM115 Porcelain White Manual
EVO Manual (Orange – 11.5) Grinder / KDM115 All surfaces EVO Manual
EVO CNC (Orange – 11.5) CNC Router All surfaces EVO CNC

Certified Performance

Keep-Nut meets ASTM C1354 and ETA testing standards. Example pull-out results:

Material Thickness Avg Pull-Out Strength
Corian 10 mm 650 lbs
Porcelain 12 mm 562 lbs
Quartz 12 mm 540 lbs
Granite 12 mm 530 lbs
Marble 12 mm 495 lbs

Compatible Surfaces

  • Natural Stone: Granite, Marble, Limestone, Travertine, Slate, Quartz, Quartzite
  • Sintered Stone: Lapitec®, Dekton®, Neolith®
  • Porcelain: Stoneware®, Sapienstone®, Crossville®
  • Solid Surface: Corian®, Krion, Staron, Wilsonart
  • Other: UHPC, GFRC, Fiberglass, HPL, Composites, Glass
Compatible Surfaces Example

Common Applications

  • Undermount Sinks
  • Interior Wall Panels
  • Custom Hood Vents
  • Fireplace Surrounds
  • Furniture & Architectural Elements

Need Help or Bulk Pricing?

Our technical sales team is ready to help you select the right tools and anchors for your shop.

Keep-Nut® Undermount Sink Anchors

Faster, Stronger, Epoxy-Free — Universal Anchoring for Stone, Quartz, Porcelain & Solid Surface

Keep-Nut® is a high-strength, stainless steel insert system that eliminates adhesives and curing time for undermount sink installations. Designed for speed and precision, Keep-Nut installs flush for a professional finish in stone, quartz, porcelain, solid surface, and more. Trusted by fabricators nationwide, it delivers the durability, reliability, and efficiency you need on every project.

Keep-Nut Anchors in Use

Why Fabricators Choose Keep-Nut®

  • Exceptional holding power – tested pull-out resistance up to 650 lbs.
  • Versatile across materials – works in granite, quartz, porcelain, Corian®, UHPC, and more.
  • Fast, epoxy-free installation – no adhesives, no mess, installs with manual tools, CNC machines, or the KDM115 system.
  • Durable stainless steel design – fully corrosion-resistant and fireproof for long-lasting performance.
  • Clean, professional finish – anchors are hidden and flush-mounted.
  • Certified reliability – ASTM and ETA tested for proven structural strength.
Keep-Nut Kit

Installation Videos

CNC Router Installation

Manual Drilling Installation

Solid Surface Installation

*For best view on mobile, please scroll tables left/right.

Keep-Nut Sets & Starter Kits

Product Description Photo
Full Sink Mounting Set Full set of Inserts and Hardware. Most sinks take 4 sets. Mounting Set
Starter Kits Includes all the essential tooling needed to begin. Starter Kit

Inserts, Fasteners & Clips

Product Description Photo
Keep-Nut™ Inserts (100-Pk) 100 Pack of Keep-Nut Inserts Only. Inserts
Mounting Hardware (100-Pk) Allen Posts, Wing Nuts, and Washers. Hardware
Z-Shaped Sink Clips (100-Pk) Stamped metal clips, Made in USA. Sink Clips

Installation Tools

Tool Function Photo
Go/No-Go Gauge Verifies correct hole dimensions prior to install. Gauge
Keep-Nut Setting Tool Ensures insert installs flush and protects surface. Setting Tool
KDM115 Drilling Machine Vacuum base drill with water feed & depth stop. KDM115

Drilling Bits – CNC & Manual

Bit Method Use Case Photo
CNC Bit (Blue – 11.8 mm) CNC Router Quartz, Stone Blue CNC
CNC Bit (White – 11.8 mm) CNC Router Porcelain White CNC
Manual Bit (Blue – 11.4) Grinder / KDM115 Quartz, Stone Blue Manual
Manual Bit (White – 11.4) Grinder / KDM115 Porcelain White Manual
EVO Manual (Orange – 11.5) Grinder / KDM115 All surfaces EVO Manual
EVO CNC (Orange – 11.5) CNC Router All surfaces EVO CNC

Certified Performance

Keep-Nut meets ASTM C1354 and ETA testing standards. Example pull-out results:

Material Thickness Avg Pull-Out Strength
Corian 10 mm 650 lbs
Porcelain 12 mm 562 lbs
Quartz 12 mm 540 lbs
Granite 12 mm 530 lbs
Marble 12 mm 495 lbs

Compatible Surfaces

  • Natural Stone: Granite, Marble, Limestone, Travertine, Slate, Quartz, Quartzite
  • Sintered Stone: Lapitec®, Dekton®, Neolith®
  • Porcelain: Stoneware®, Sapienstone®, Crossville®
  • Solid Surface: Corian®, Krion, Staron, Wilsonart
  • Other: UHPC, GFRC, Fiberglass, HPL, Composites, Glass
Compatible Surfaces Example

Common Applications

  • Undermount Sinks
  • Interior Wall Panels
  • Custom Hood Vents
  • Fireplace Surrounds
  • Furniture & Architectural Elements

Need Help or Bulk Pricing?

Our technical sales team is ready to help you select the right tools and anchors for your shop.

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