For a deep 16-gauge bowl in a 33-inch cabinet, pick the Kraus KHU100-30. For a longer 18-gauge bowl, the Kraus KBU14. For quartz composite, the Elkay ELGU13322. For an accessible kitchen, the Elkay ELUHAD211555.
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This guide compares four undermount kitchen sinks using Kraus and Elkay spec sheets.
Undermount kitchen sinks compared (maker spec sheets)
On a phone, swipe or scroll the table sideways to see every column.
| Model | Material | Size | Depth | Min. cabinet |
|---|---|---|---|---|
| Kraus KHU100-30 | 16-gauge stainless | 30 x 18 in. | 10 in. | 33 in. |
| Kraus KBU14 | 18-gauge stainless | 31-1/2 x 18-3/8 in. | 9-1/4 in. bowl | 36 in. |
| Elkay Quartz Classic ELGU13322 | Quartz composite | 33 x 18-3/4 in. | 9-1/2 in. | 36 in. |
| Elkay Lustertone ELUHAD211555 | 18-gauge stainless | 23-1/2 x 18-1/4 in. | 5-3/8 in. | 27 in. |
An undermount sink is attached to the underside of a solid countertop, so there is no rim on top to catch crumbs and you can wipe the counter straight into the bowl. It needs a counter that can take a finished cut edge, such as stone or quartz. Every sink here is a single bowl; for two bowls, see our double bowl kitchen sink guide, and for all kitchen sink types, our kitchen sink guide.
Kraus KHU100-30: 16-gauge, 10 inches deep
Choose the KHU100-30 for a 33-inch cabinet and a deep, tight-cornered bowl. Kraus’s spec sheet (kraususa.com) lists 16-gauge stainless steel, a handmade single bowl undermount design, a 30 by 18-inch outside size, a 28 by 16-inch bowl and a 10-inch depth.
It lists a 33-inch minimum cabinet width, a rear center-set drain with a 3-1/2-inch opening, NoiseDefend undercoating and sound dampening pads, and includes a basket strainer, bottom grid, cut-out template, mounting hardware and a towel. On October 15, 2026, the standard new offer sold by Amazon.com was in stock with model KHU100-30.
Check Kraus KHU100-30 undermount kitchen sink on Amazon →
Kraus KBU14: a wider 18-gauge bowl
Choose the KBU14 for a longer bowl with rounded corners. Kraus’s spec sheet (kraususa.com) lists 18-gauge stainless steel, a pressed single bowl undermount design, a 31-1/2 by 18-3/8-inch outside size, a 29-1/2 by 16-1/4-inch bowl and a 9-1/4-inch bowl depth, with 3-1/2-inch corner radii in the drawing.
It lists a 36-inch minimum cabinet width, a center-set drain with a 3-1/2-inch opening, NoiseDefend undercoating and sound dampening pads, and includes a strainer, cut-out template and mounting hardware. A bottom grid is not on its included list. On October 15, 2026, the standard new offer sold by Amazon.com was in stock with model KBU14.
Check Kraus KBU14 undermount kitchen sink on Amazon →
Elkay Quartz Classic ELGU13322: composite, not steel
Choose the Quartz Classic if you want a colored, non-metal sink. Elkay’s spec sheet (elkayfiles.com) says the sink is molded with up to 80% natural quartz and acrylic resins, lists a 33 by 18-3/4 by 9-1/2-inch sink with a 30-5/16 by 16-7/16-inch bowl, and describes it as naturally sound deadening.
The drain is a 3-1/2-inch opening at the rear right. Elkay lists a 36-inch minimum cabinet, mounting hardware and a template included, and five finishes; the linked offer is white, model ELGU13322WH0. On October 15, 2026, the standard new offer sold by Amazon.com showed limited stock. More in our Elkay sink guide.
Check Elkay Quartz Classic ELGU13322WH0 undermount sink on Amazon →
Elkay Lustertone ELUHAD211555: shallow ADA bowl
Choose the ELUHAD211555 for an accessible kitchen or a small 27-inch base. Elkay’s spec sheet (elkayfiles.com) lists 18-gauge 304 stainless steel with a lustrous satin finish, a 23-1/2 by 18-1/4 by 5-3/8-inch sink, a 21 by 15-3/4-inch bowl, a rear center 3-1/2-inch drain and pads on the bottom only.
It lists compliance with ADA and ICC A117.1 accessibility requirements and a 27-inch minimum cabinet. Note that the sheet says undermount brackets are sold separately; the template is included. On October 15, 2026, the standard new offer sold by Amazon.com was in stock with model ELUHAD211555.
Check Elkay Lustertone ELUHAD211555 ADA undermount sink on Amazon →
16-gauge or 18-gauge?
Gauge is steel thickness; the lower number is thicker. The KHU100-30 is 16-gauge, while the KBU14 and the Elkay ADA sink are 18-gauge. Kraus also lists different construction: the KHU100-30 is handmade with tight corners, and the KBU14 is pressed with rounded corners. Rounded corners are easier to wipe; tight corners give more flat bottom area. The quartz Elkay is not graded by gauge at all.
Stainless or quartz?
Three of the four sinks here are stainless steel; the fourth is quartz composite. Elkay describes its quartz sink as non-porous, with heat, scratch, fade and stain resistance; those are the maker’s claims, and we have not tested them. Elkay lists five finishes for the quartz sink, from white to matte black. Both Kraus sheets list NoiseDefend undercoating and pads for sound, Elkay lists pads on the bottom of its ADA sink, and it calls the quartz sink naturally sound deadening.
Fitting the sink to your cabinet
The minimum cabinet width on each sheet is the base cabinet under the sink, measured left to right. Kraus also lists 24 inches front to back for both its sinks. A 30-inch sink like the KHU100-30 needs a 33-inch base, while the 31-1/2-inch KBU14 and the 33-inch quartz sink need 36 inches. The ADA sink, at 23-1/2 inches wide, fits a 27-inch base. Measure inside the cabinet as well, since a disposal and drain pipes have to fit below the bowl.
How undermount sinks are held up
An undermount sink hangs from the countertop, so its mounting matters. Kraus and the Elkay quartz model include mounting hardware; the Elkay ADA sink does not. Installers often add a bead of sink adhesive or silicone between the rim and the counter; see our undermount sink adhesive guide and sink mounting clip guide. Each sink comes with a cut-out template, which the countertop fabricator uses to cut and finish the opening, so choose the sink before the counter is cut.
Drains and accessories
All four sinks use a standard 3-1/2-inch drain opening, the common size for kitchen basket strainers and disposal flanges; see our basket strainer guide. Drain position varies: rear center on the KHU100-30 and the ADA sink, center on the KBU14 and rear right on the quartz sink. If you want a bottom grid for a sink that does not include one, our sink grid guide covers options; match the grid to the bowl size in the table.
Check these before you order
- Cabinet. 27 to 36 inches minimum by model.
- Material. Stainless or quartz composite.
- Depth. 5-3/8 inches on the ADA sink, about 9 to 10 on the rest.
- Hardware. ADA sink brackets sold separately.
- Drain. Center, rear center or rear right.
- Counter. Solid surface that can take a finished cut edge.
Which undermount kitchen sink should you buy?
For a 33-inch cabinet and a deep 16-gauge bowl, the Kraus KHU100-30. For a longer 18-gauge bowl with rounded corners, the Kraus KBU14. For a non-metal sink with a rear drain, the Elkay Quartz Classic ELGU13322. For an accessible or small-base kitchen, the Elkay Lustertone ELUHAD211555, with brackets bought separately.
Frequently asked questions
What is an undermount kitchen sink?
A sink fastened to the underside of a solid countertop, with no rim on top of the counter.
Which undermount sink here fits a 33-inch cabinet?
The Kraus KHU100-30 lists a 33-inch minimum; the Elkay ADA sink lists 27 inches.
Which is deepest?
The Kraus KHU100-30, at 10 inches.
Do these include mounting hardware?
The Kraus sinks and the Elkay quartz sink do; the Elkay ADA sink’s brackets are sold separately.
Can I put an undermount sink in a laminate counter?
Undermount sinks need a counter with a finished cut edge, such as stone or quartz; check with your counter maker.
How we chose
This document-based guide makes no hands-on testing claim. We read Kraus’s sheets for the KHU100-30 and KBU14 and Elkay’s sheets for the Quartz Classic ELGU13322 and Lustertone ELUHAD211555. On October 15, 2026, we checked each linked standard new Amazon offer for model, seller, stock and an add-to-cart button. Read our selection method and about Plumbing Picks.
Primary sources
- Kraus KHU100-30 spec sheet (kraususa.com): 16-gauge.
- Kraus KBU14 spec sheet (kraususa.com): 18-gauge.
- Elkay ELGU13322 spec sheet (elkayfiles.com): quartz.
- Elkay ELUHAD211555 spec sheet (elkayfiles.com): ADA.