KRAUS 31" Undermount Single Bowl Black Onyx Granite Kitchen Sink - KGU-413B

KRAUS 31" Undermount Single Bowl Black Onyx Granite Kitchen Sink - KGU-413B

Beautiful and versatile, Quarza granite kitchen sinks are made from quartz composite material that brings the high-end look of natural granite with rounded corners and smooth easy-clean surface. White kitchen sink offers a clean, bright aesthetic that works with any kitchen from classic to modern and pairs with trending black faucet finish. Undermount sink installation simplifies cleanup by letting you wipe water right into the sink. Durable sink for kitchen stands up to impact, scratches and shock. White sink is colored all the way through to resist fading. Deep sink with sloped bottom for easy draining has ample room for large items. Installation-ready white granite sink comes with drain and hardware. Quarza sink is also available as drop in sink to install with any countertop material.

Features

• • GRANITE KITCHEN SINK: Durable kitchen sink is made from advanced quartz composite material that delivers the elegant look of natural granite with great resistance to impact, scratches, and thermal shock
  • EXTERNAL DIMS: 30 1/2” L x 17” W x 9 1/4” D – BOWL DIMS: 28 3/8” L x 14 1/2” W x 8 7/8” D – MIN CABINET SIZE: 33”
  • KIT INCLUDES: White granite sink, stainless steel drain assembly with removable strainer, heat-resistant silicone mitt and trivet, mounting hardware, cut-out template 
  • ADVANCED QUARTZ COMPOSITE SINK: White kitchen sink is made from natural quartz and premium acrylic resin, with a hard, smooth, non-porous surface for durability and easy cleaning
  • WHITE SINK offers timeless versatility, balancing classic charm with modern style to create a clean, bright look that makes any space feel lighter and more open – Pairs with trending gold faucet or black faucet finish and works with any style of kitchen 
  • UNDERMOUNT SINK INSTALLATION creates a seamless transition from sink to countertop with no exposed mounting deck to trap debris – Simplifies cleanup by letting you wipe water and crumbs right into the sink
  • EASY TO CLEAN: Sink for kitchen with smooth non-porous surface resists stains and stands up to household cleaners – Gently rounded corners minimize build-up for easy maintenance 
  • SPACIOUS SINGLE BOWL SINK offers generous workspace for oversized cookware, with a deep kitchen sink bowl that helps contain mess and splatter – Rear-offset drain creates an uninterrupted work surface and maximizes usable storage space under the sink
  • ENGINEERED FOR EASY DRAINING: Gently sloped bottom and smooth surface help keep water from pooling in the sink – OPTIMIZED SLOPE helps stop fragile glassware from tipping over
  • COLOR-STABLE MATERIAL: Vivid color penetrates all the way through the material for a lasting beautiful look that resists fading – HEAT SAFE up to 500°F to stand up to hot cookware
  • NATURALLY SOUND-ABSORBING material helps reduce noise and vibration from dishes and garbage disposal for a quieter kitchen sink
  • STAINLESS STEEL DRAIN ASSEMBLY with removable strainer catches food waste to help prevent clogging the drainpipe, strainer lifts out for easy cleaning – Included silicone mitt and trivet protect your hands and counters from hot items
  • INSTALLATION-READY SINK comes with all mounting hardware and cut-out template for undermount kitchen sink installation
  • UNIVERSAL DESIGN with soft lines and rounded corners offers an elegant look that complements the style of any kitchen – Kraus granite sinks are also available in drop in sink models that install with any countertop material

   

  What our Experts Think

  • Premium Granite Composite Durability
    The KRAUS Forteza 31" Undermount Single Bowl Black Onyx Granite Kitchen Sink (KGU-413B) is crafted from quartz composite engineered for stone-like strength, delivering excellent resistance to scratches, chips, heat, and daily wear.
  • Sleek Undermount Seamless Design
    Designed for undermount installation, it creates a flush transition with countertops, allowing easy wipe-down of crumbs and water directly into the sink for a cleaner kitchen workflow.
  • Compact Yet Highly Functional 31" Basin
    The single-bowl layout offers a spacious, uninterrupted washing area, ideal for large cookware while still fitting standard 33" base cabinet configurations.
  • Naturally Quiet Performance
    Dense granite composite construction provides excellent sound absorption, reducing noise from dishwashing and running water for a quieter kitchen environment.
  • Heat, Stain & Impact Resistant Surface
    Engineered with a thermal finishing process, the sink surface is highly resistant to heat damage, staining, and discoloration, ensuring long-term visual appeal.
  • Easy-Clean Rounded Corners
    Gently curved interior edges are designed to prevent debris buildup and simplify maintenance, supporting better hygiene with less effort.
  • Modern Black Onyx Aesthetic
    The deep matte black finish delivers a bold, contemporary stone look that pairs well with modern fixtures and minimalist kitchen designs.
  • Expert Verdict
    A strong choice for homeowners wanting a durable, low-maintenance granite sink with premium aesthetics and everyday practicality, especially for modern remodels focused on style + performance.

  
  Q&A

  Q1: What material is this sink made of?
  A: It is made from granite composite (about 80% natural quartz and acrylic resin), offering a natural stone look with high durability and strength.

  Q2: What installation type does it use?
  A: It features an undermount design, creating a seamless transition from countertop to sink for a clean, modern finish.

  Q3: What are the sink dimensions?
  A: The sink measures approximately 31-1/2" x 17" x 8-7/8" and requires a minimum 33" cabinet base.

  Q4: Is it resistant to heat, stains, and scratches?
  A: Yes, the granite composite surface is highly resistant to heat, chipping, scratching, and discoloration due to a thermal finishing process.

  Q5: Is the sink noisy during use?
  A: No, the non-porous granite material naturally absorbs sound, making it quieter than stainless steel sinks.

  Q6: Does it have a deep bowl?
  A: Yes, it features an extra-deep single bowl design, ideal for washing large pots, pans, and cookware.

  Q7: Is it easy to clean?
  A: Yes, the smooth, non-porous surface and rounded corners make cleaning simple and help prevent buildup.

  Q8: Does it come with installation accessories?
  A: Yes, it typically includes mounting hardware, template, and installation accessories for easier setup.

  
  Maintenance Tips

  • Clean daily with mild dish soap + soft sponge – Keeps the non-porous granite surface smooth and prevents residue buildup.
  • Rinse and dry after each use – Prevents water spots, clouding, and mineral deposits, especially on the black onyx finish.
  • Avoid harsh chemicals – No bleach, ammonia, or acidic cleaners; they can damage the protective resin layer.
  • No abrasive pads or steel wool – These can scratch and dull the surface over time.
  • Use a sink grid for protection – Helps prevent scratches from heavy cookware and maintains the deep basin finish.
  • Clean stains early – Coffee, tea, and food residues should be wiped promptly to avoid dark staining or dull spots.
  • Occasional deep clean – Use baking soda paste or manufacturer-approved non-abrasive cleaners for stubborn marks.
  • Prevent standing water – Keeps the sink looking uniformly dark and avoids mineral outlines.
  • Maintain drain area regularly – Flush with warm water to prevent debris buildup and odor in the rear drain system.